Python: Hyperlight: thread-confine sandbox, skip parsing on host callbacks, schema/tool cleanup (#5424)

* improved parsing of tool call results and tweaks

* Address PR review: skip_parsing flag, broader registry close, comment fix

- FunctionTool.invoke now takes a boolean skip_parsing flag instead of the
  SKIP_PARSING sentinel; the sentinel is still accepted as result_parser at
  construction time to opt out of parsing for every call. The two paths are
  equivalent.
- _SandboxRegistry.close now invokes any sandbox close/shutdown hook on the
  entry's own worker thread (PyO3 unsendable), then shuts the worker down,
  then cleans up the per-entry temporary directories.
- Clarified the _SandboxWorker.shutdown comment to describe the actual
  ThreadPoolExecutor.shutdown(wait=False, cancel_futures=False) semantics.
- Hyperlight host callback uses skip_parsing=True (the new flag).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Drop redundant 'is not SKIP_PARSING' guard that mypy 1.x flags

After callable(configured_parser) the sentinel is already excluded; the extra
identity check tripped mypy's non-overlapping identity warning.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fixed sandbox working on copy of tool

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

.github/workflows/devflow-pr-review.yml

@@ -0,0 +1,165 @@
+name: DevFlow PR Review
+
+on:
+  pull_request_target:
+    types:
+      - opened
+      - reopened
+      - ready_for_review
+  workflow_dispatch:
+    inputs:
+      pr_number:
+        description: Pull request number to review
+        required: true
+        type: string
+
+permissions:
+  contents: read
+  issues: write
+  pull-requests: write
+
+concurrency:
+  group: devflow-pr-review-${{ github.repository }}-${{ github.event.pull_request.number || inputs.pr_number || github.run_id }}
+  cancel-in-progress: true
+
+env:
+  DEVFLOW_REPOSITORY: ${{ vars.DF_REPO }}
+  DEVFLOW_REF: main
+  TARGET_REPO_PATH: ${{ github.workspace }}/target-repo
+  DEVFLOW_PATH: ${{ github.workspace }}/devflow
+
+jobs:
+  team_check:
+    runs-on: ubuntu-latest
+    outputs:
+      is_team_member: ${{ steps.check.outputs.is_team_member }}
+      pr_number: ${{ steps.pr.outputs.pr_number }}
+      pr_url: ${{ steps.pr.outputs.pr_url }}
+      repo: ${{ steps.pr.outputs.repo }}
+    steps:
+      - name: Resolve PR metadata
+        id: pr
+        shell: bash
+        env:
+          PR_HTML_URL: ${{ github.event.pull_request.html_url }}
+          PR_NUMBER_EVENT: ${{ github.event.pull_request.number }}
+          PR_NUMBER_INPUT: ${{ inputs.pr_number }}
+        run: |
+          set -euo pipefail
+
+          if [[ "${GITHUB_EVENT_NAME}" == "pull_request_target" ]]; then
+            pr_number="${PR_NUMBER_EVENT}"
+            pr_url="${PR_HTML_URL}"
+          else
+            pr_number="${PR_NUMBER_INPUT}"
+            pr_url="https://github.com/${GITHUB_REPOSITORY}/pull/${pr_number}"
+          fi
+
+          if [[ ! "$pr_number" =~ ^[1-9][0-9]*$ ]]; then
+            echo "Could not determine PR number; for workflow_dispatch runs, the 'pr_number' input is required when not running on pull_request_target." >&2
+            exit 1
+          fi
+
+          echo "pr_url=${pr_url}" >> "$GITHUB_OUTPUT"
+          echo "pr_number=${pr_number}" >> "$GITHUB_OUTPUT"
+          echo "repo=${GITHUB_REPOSITORY}" >> "$GITHUB_OUTPUT"
+
+      - name: Check PR author team membership
+        id: check
+        uses: actions/github-script@v8
+        env:
+          TEAM_NAME: ${{ secrets.DEVELOPER_TEAM }}
+          PR_NUMBER: ${{ steps.pr.outputs.pr_number }}
+        with:
+          github-token: ${{ secrets.GH_ACTIONS_PR_WRITE }}
+          script: |
+            let author = context.payload.pull_request?.user?.login;
+            if (!author) {
+              const { data: pr } = await github.rest.pulls.get({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                pull_number: Number(process.env.PR_NUMBER),
+              });
+              author = pr.user.login;
+            }
+
+            let isTeamMember = false;
+            try {
+              const teamMembership = await github.rest.teams.getMembershipForUserInOrg({
+                org: context.repo.owner,
+                team_slug: process.env.TEAM_NAME,
+                username: author,
+              });
+              isTeamMember = teamMembership.data.state === 'active';
+            } catch (error) {
+              console.log(`Team membership lookup failed for ${author}: ${error.message}`);
+              isTeamMember = false;
+            }
+
+            core.setOutput('is_team_member', isTeamMember ? 'true' : 'false');
+            if (isTeamMember) {
+              core.info(`Author ${author} is a team member; proceeding with review.`);
+            } else {
+              core.info(`Author ${author} is not a member of ${process.env.TEAM_NAME}; skipping review.`);
+            }
+
+  review:
+    runs-on: ubuntu-latest
+    needs: team_check
+    if: ${{ needs.team_check.outputs.is_team_member == 'true' }}
+    timeout-minutes: 60
+    # Advisory check: failures here should not block the PR. The reviewer
+    # posts comments as a best-effort signal; if the pipeline breaks, the
+    # PR author should still be able to merge without a red required check.
+    continue-on-error: true
+
+    steps:
+      # Safe checkout: base repo only, not the untrusted PR head.
+      - name: Checkout target repo base
+        uses: actions/checkout@v6
+        with:
+          ref: ${{ github.event_name == 'pull_request_target' && github.event.pull_request.base.sha || github.sha }}
+          fetch-depth: 0
+          persist-credentials: false
+          path: target-repo
+
+      # Private DevFlow checkout: the PAT/token grants access to this repo's code.
+      - name: Checkout DevFlow
+        uses: actions/checkout@v6
+        with:
+          repository: ${{ env.DEVFLOW_REPOSITORY }}
+          ref: ${{ env.DEVFLOW_REF }}
+          token: ${{ secrets.DEVFLOW_TOKEN }}
+          fetch-depth: 1
+          persist-credentials: false
+          path: devflow
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.13"
+
+      - name: Set up uv
+        uses: astral-sh/setup-uv@v7
+        with:
+          version: "0.11.x"
+          enable-cache: true
+
+      - name: Install DevFlow dependencies
+        working-directory: ${{ env.DEVFLOW_PATH }}
+        run: uv sync --frozen
+
+      - name: Run PR review
+        id: review
+        working-directory: ${{ env.DEVFLOW_PATH }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GH_COPILOT_TOKEN: ${{ secrets.GH_COPILOT_TOKEN }}
+          SK_REPO_PATH: ${{ env.TARGET_REPO_PATH }}
+          AGENT_REPO_PATH: ${{ env.TARGET_REPO_PATH }}
+          PR_URL: ${{ needs.team_check.outputs.pr_url }}
+        run: |
+          uv run python scripts/trigger_pr_review.py \
+            --pr-url "$PR_URL" \
+            --github-username "$GITHUB_ACTOR" \
+            --no-require-comment-selection

.github/workflows/python-integration-tests.yml

@@ -87,6 +87,14 @@ jobs:
           -n logical --dist worksteal
           --timeout=120 --session-timeout=900 --timeout_method thread
           --retries 2 --retry-delay 5
+          --junitxml=pytest.xml
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: test-results-openai
+          path: ./python/pytest.xml
+          if-no-files-found: ignore
 
   # Azure OpenAI integration tests
   python-tests-azure-openai:
@@ -130,6 +138,14 @@ jobs:
           -n logical --dist worksteal
           --timeout=120 --session-timeout=900 --timeout_method thread
           --retries 2 --retry-delay 5
+          --junitxml=pytest.xml
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: test-results-azure-openai
+          path: ./python/pytest.xml
+          if-no-files-found: ignore
 
   # Misc integration tests (Anthropic, Hyperlight, Ollama, MCP)
   python-tests-misc-integration:
@@ -173,6 +189,14 @@ jobs:
           -n logical --dist worksteal
           --timeout=120 --session-timeout=900 --timeout_method thread
           --retries 2 --retry-delay 30
+          --junitxml=pytest.xml
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: test-results-misc
+          path: ./python/pytest.xml
+          if-no-files-found: ignore
       - name: Stop local MCP server
         if: always()
         shell: bash
@@ -249,6 +273,14 @@ jobs:
           -x
           --timeout=360 --session-timeout=900 --timeout_method thread
           --retries 2 --retry-delay 5
+          --junitxml=pytest.xml
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: test-results-functions
+          path: ./python/pytest.xml
+          if-no-files-found: ignore
 
   # Foundry integration tests
   python-tests-foundry:
@@ -295,6 +327,14 @@ jobs:
           -n logical --dist worksteal
           --timeout=120 --session-timeout=900 --timeout_method thread
           --retries 2 --retry-delay 5
+          --junitxml=pytest.xml
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: test-results-foundry
+          path: ./python/pytest.xml
+          if-no-files-found: ignore
 
   # Azure Cosmos integration tests
   python-tests-cosmos:
@@ -339,7 +379,80 @@ jobs:
           echo "Cosmos DB emulator did not become ready in time." >&2
           exit 1
       - name: Test with pytest (Cosmos integration)
-        run: uv run --directory packages/azure-cosmos poe integration-tests -n logical --dist worksteal --timeout=120 --session-timeout=900 --timeout_method thread --retries 2 --retry-delay 5
+        run: uv run --directory packages/azure-cosmos poe integration-tests -n logical --dist worksteal --timeout=120 --session-timeout=900 --timeout_method thread --retries 2 --retry-delay 5 --junitxml=${{ github.workspace }}/python/pytest.xml
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: test-results-cosmos
+          path: ./python/pytest.xml
+          if-no-files-found: ignore
+
+  # Flaky test trend report (aggregates per-job JUnit XML results)
+  python-flaky-test-report:
+    name: Flaky Test Report
+    if: >
+      always() &&
+      (contains(join(needs.*.result, ','), 'success') ||
+       contains(join(needs.*.result, ','), 'failure'))
+    needs:
+      [
+        python-tests-openai,
+        python-tests-azure-openai,
+        python-tests-misc-integration,
+        python-tests-functions,
+        python-tests-foundry,
+        python-tests-cosmos,
+      ]
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: python
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          ref: ${{ inputs.checkout-ref }}
+          persist-credentials: false
+      - name: Set up python and install the project
+        uses: ./.github/actions/python-setup
+        with:
+          python-version: ${{ env.UV_PYTHON }}
+          os: ${{ runner.os }}
+      - name: Download all test results from current run
+        uses: actions/download-artifact@v4
+        with:
+          pattern: test-results-*
+          path: test-results/
+      - name: Restore flaky report history cache
+        uses: actions/cache/restore@v4
+        with:
+          path: python/flaky-report-history.json
+          key: flaky-report-history-integration-${{ github.run_id }}
+          restore-keys: |
+            flaky-report-history-integration-
+      - name: Generate trend report
+        run: >
+          uv run python scripts/flaky_report/aggregate.py
+          ../test-results/
+          flaky-report-history.json
+          flaky-test-report.md
+      - name: Post to Job Summary
+        if: always()
+        run: cat flaky-test-report.md >> $GITHUB_STEP_SUMMARY
+      - name: Save flaky report history cache
+        if: always()
+        uses: actions/cache/save@v4
+        with:
+          path: python/flaky-report-history.json
+          key: flaky-report-history-integration-${{ github.run_id }}
+      - name: Upload unified trend report
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: flaky-test-report
+          path: |
+            python/flaky-test-report.md
+            python/flaky-report-history.json
 
   python-integration-tests-check:
     if: always()

.github/workflows/python-merge-tests.yml

@@ -181,6 +181,13 @@ jobs:
           display-options: fEX
           fail-on-empty: false
           title: OpenAI integration test results
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: test-results-openai
+          path: ./python/pytest.xml
+          if-no-files-found: ignore
 
   # Azure OpenAI integration tests
   python-tests-azure-openai:
@@ -244,6 +251,13 @@ jobs:
           display-options: fEX
           fail-on-empty: false
           title: Azure OpenAI integration test results
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: test-results-azure-openai
+          path: ./python/pytest.xml
+          if-no-files-found: ignore
 
   # Misc integration tests (Anthropic, Ollama, MCP)
   python-tests-misc-integration:
@@ -321,6 +335,13 @@ jobs:
           display-options: fEX
           fail-on-empty: false
           title: Misc integration test results
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: test-results-misc
+          path: ./python/pytest.xml
+          if-no-files-found: ignore
 
   # Azure Functions + Durable Task integration tests
   python-tests-functions:
@@ -392,6 +413,13 @@ jobs:
           display-options: fEX
           fail-on-empty: false
           title: Functions integration test results
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: test-results-functions
+          path: ./python/pytest.xml
+          if-no-files-found: ignore
 
   python-tests-foundry:
     name: Python Integration Tests - Foundry
@@ -409,6 +437,10 @@ jobs:
       FOUNDRY_MODEL: ${{ vars.FOUNDRY_MODEL }}
       FOUNDRY_AGENT_NAME: ${{ vars.FOUNDRY_AGENT_NAME }}
       FOUNDRY_AGENT_VERSION: ${{ vars.FOUNDRY_AGENT_VERSION }}
+      FOUNDRY_MODELS_ENDPOINT: ${{ vars.FOUNDRY_MODELS_ENDPOINT || '' }}
+      FOUNDRY_MODELS_API_KEY: ${{ secrets.FOUNDRY_MODELS_API_KEY || '' }}
+      FOUNDRY_EMBEDDING_MODEL: ${{ vars.FOUNDRY_EMBEDDING_MODEL || '' }}
+      FOUNDRY_IMAGE_EMBEDDING_MODEL: ${{ vars.FOUNDRY_IMAGE_EMBEDDING_MODEL || '' }}
       LOCAL_MCP_URL: ${{ vars.LOCAL_MCP__URL }}
     defaults:
       run:
@@ -448,6 +480,13 @@ jobs:
           display-options: fEX
           fail-on-empty: false
           title: Test results
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: test-results-foundry
+          path: ./python/pytest.xml
+          if-no-files-found: ignore
 
   # TODO: Add python-tests-lab
 
@@ -497,7 +536,7 @@ jobs:
           echo "Cosmos DB emulator did not become ready in time." >&2
           exit 1
       - name: Test with pytest (Cosmos integration)
-        run: uv run --directory packages/azure-cosmos poe integration-tests -n logical --dist worksteal --timeout=120 --session-timeout=900 --timeout_method thread --retries 2 --retry-delay 5 --junitxml=pytest.xml
+        run: uv run --directory packages/azure-cosmos poe integration-tests -n logical --dist worksteal --timeout=120 --session-timeout=900 --timeout_method thread --retries 2 --retry-delay 5 --junitxml=${{ github.workspace }}/python/pytest.xml
         working-directory: ./python
       - name: Surface failing tests
         if: always()
@@ -508,6 +547,76 @@ jobs:
           display-options: fEX
           fail-on-empty: false
           title: Cosmos integration test results
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: test-results-cosmos
+          path: ./python/pytest.xml
+          if-no-files-found: ignore
+
+  # Flaky test trend report (aggregates per-job JUnit XML results)
+  python-flaky-test-report:
+    name: Flaky Test Report
+    if: >
+      always() &&
+      (contains(join(needs.*.result, ','), 'success') ||
+       contains(join(needs.*.result, ','), 'failure'))
+    needs:
+      [
+        python-tests-openai,
+        python-tests-azure-openai,
+        python-tests-misc-integration,
+        python-tests-functions,
+        python-tests-foundry,
+        python-tests-cosmos,
+      ]
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: python
+    steps:
+      - uses: actions/checkout@v6
+      - name: Set up python and install the project
+        uses: ./.github/actions/python-setup
+        with:
+          python-version: ${{ env.UV_PYTHON }}
+          os: ${{ runner.os }}
+      - name: Download all test results from current run
+        uses: actions/download-artifact@v4
+        with:
+          pattern: test-results-*
+          path: test-results/
+      - name: Restore flaky report history cache
+        uses: actions/cache/restore@v4
+        with:
+          path: python/flaky-report-history.json
+          key: flaky-report-history-merge-${{ github.run_id }}
+          restore-keys: |
+            flaky-report-history-merge-
+      - name: Generate trend report
+        run: >
+          uv run python scripts/flaky_report/aggregate.py
+          ../test-results/
+          flaky-report-history.json
+          flaky-test-report.md
+      - name: Post to Job Summary
+        if: always()
+        run: cat flaky-test-report.md >> $GITHUB_STEP_SUMMARY
+      - name: Save flaky report history cache
+        if: always()
+        uses: actions/cache/save@v4
+        with:
+          path: python/flaky-report-history.json
+          key: flaky-report-history-merge-${{ github.run_id }}
+      - name: Upload unified trend report
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: flaky-test-report
+          path: |
+            python/flaky-test-report.md
+            python/flaky-report-history.json
 
   python-integration-tests-check:
     if: always()

dotnet/Directory.Packages.props

@@ -42,15 +42,15 @@
     <!-- System.* -->
     <PackageVersion Include="Microsoft.Bcl.AsyncInterfaces" Version="10.0.6" />
     <PackageVersion Include="Microsoft.Bcl.HashCode" Version="6.0.0" />
-    <PackageVersion Include="Microsoft.Bcl.Memory" Version="10.0.4" />
+    <PackageVersion Include="Microsoft.Bcl.Memory" Version="10.0.5" />
     <PackageVersion Include="System.ClientModel" Version="1.10.0" />
     <PackageVersion Include="System.CodeDom" Version="10.0.0" />
     <PackageVersion Include="System.Collections.Immutable" Version="10.0.1" />
     <PackageVersion Include="System.CommandLine" Version="2.0.0-rc.2.25502.107" />
     <PackageVersion Include="System.Diagnostics.DiagnosticSource" Version="10.0.6" />
-    <PackageVersion Include="System.Linq.AsyncEnumerable" Version="10.0.4" />
+    <PackageVersion Include="System.Linq.AsyncEnumerable" Version="10.0.5" />
     <PackageVersion Include="System.Net.Http.Json" Version="10.0.0" />
-    <PackageVersion Include="System.Net.ServerSentEvents" Version="10.0.4" />
+    <PackageVersion Include="System.Net.ServerSentEvents" Version="10.0.5" />
     <PackageVersion Include="System.Text.Json" Version="10.0.6" />
     <PackageVersion Include="System.Threading.Channels" Version="10.0.6" />
     <PackageVersion Include="System.Threading.Tasks.Extensions" Version="4.6.3" />
@@ -104,8 +104,8 @@
     <PackageVersion Include="Microsoft.Agents.Authentication.Msal" Version="1.3.171-beta" />
     <PackageVersion Include="Microsoft.Agents.Hosting.AspNetCore" Version="1.3.171-beta" />
     <!-- A2A -->
-    <PackageVersion Include="A2A" Version="0.3.4-preview" />
-    <PackageVersion Include="A2A.AspNetCore" Version="0.3.4-preview" />
+    <PackageVersion Include="A2A" Version="1.0.0-preview2" />
+    <PackageVersion Include="A2A.AspNetCore" Version="1.0.0-preview2" />
     <!-- MCP -->
     <PackageVersion Include="ModelContextProtocol" Version="1.1.0" />
     <!-- Inference SDKs -->

dotnet/agent-framework-dotnet.slnx

@@ -344,11 +344,13 @@
     <Project Path="samples/04-hosting/DurableAgents/ConsoleApps/06_LongRunningTools/06_LongRunningTools.csproj" />
     <Project Path="samples/04-hosting/DurableAgents/ConsoleApps/07_ReliableStreaming/07_ReliableStreaming.csproj" />
   </Folder>
-  <Folder Name="/Samples/04-hosting/A2A/">
-    <File Path="samples/04-hosting/A2A/README.md" />
-    <Project Path="samples/04-hosting/A2A/A2AAgent_AsFunctionTools/A2AAgent_AsFunctionTools.csproj" />
-    <Project Path="samples/04-hosting/A2A/A2AAgent_PollingForTaskCompletion/A2AAgent_PollingForTaskCompletion.csproj" />
-  </Folder>
+  <Folder Name="/Samples/02-agents/A2A/">
+    <File Path="samples/02-agents/A2A/README.md" />
+    <Project Path="samples/02-agents/A2A/A2AAgent_AsFunctionTools/A2AAgent_AsFunctionTools.csproj" />
+    <Project Path="samples/02-agents/A2A/A2AAgent_PollingForTaskCompletion/A2AAgent_PollingForTaskCompletion.csproj" />
+    <Project Path="samples/02-agents/A2A/A2AAgent_StreamReconnection/A2AAgent_StreamReconnection.csproj" />
+    <Project Path="samples/02-agents/A2A/A2AAgent_ProtocolSelection/A2AAgent_ProtocolSelection.csproj" />
+  </Folder>  
   <Folder Name="/Samples/05-end-to-end/">
     <Project Path="samples/05-end-to-end/AgentWithPurview/AgentWithPurview.csproj" />
     <Project Path="samples/05-end-to-end/M365Agent/M365Agent.csproj" />

dotnet/samples/02-agents/A2A/A2AAgent_PollingForTaskCompletion/A2AAgent_PollingForTaskCompletion.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net10.0</TargetFramework>
+    <TargetFrameworks>net10.0</TargetFrameworks>
 
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
@@ -13,7 +13,6 @@
     <PackageReference Include="Azure.AI.OpenAI" />
     <PackageReference Include="Azure.Identity" />
     <PackageReference Include="Microsoft.Extensions.Hosting" />
-    <PackageReference Include="System.Net.ServerSentEvents" />
   </ItemGroup>
 
   <ItemGroup>

dotnet/samples/02-agents/A2A/A2AAgent_PollingForTaskCompletion/Program.cs

@@ -18,8 +18,12 @@ AIAgent agent = agentCard.AsAIAgent();
 
 AgentSession session = await agent.CreateSessionAsync();
 
+// AllowBackgroundResponses must be true so the server returns immediately with a continuation token
+// instead of blocking until the task is complete.
+AgentRunOptions options = new() { AllowBackgroundResponses = true };
+
 // Start the initial run with a long-running task.
-AgentResponse response = await agent.RunAsync("Conduct a comprehensive analysis of quantum computing applications in cryptography, including recent breakthroughs, implementation challenges, and future roadmap. Please include diagrams and visual representations to illustrate complex concepts.", session);
+AgentResponse response = await agent.RunAsync("Conduct a comprehensive analysis of quantum computing applications in cryptography, including recent breakthroughs, implementation challenges, and future roadmap. Please include diagrams and visual representations to illustrate complex concepts.", session, options: options);
 
 // Poll until the response is complete.
 while (response.ContinuationToken is { } token)

dotnet/samples/02-agents/A2A/A2AAgent_ProtocolSelection/A2AAgent_ProtocolSelection.csproj

@@ -0,0 +1,19 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFrameworks>net10.0</TargetFrameworks>
+
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="A2A" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\..\src\Microsoft.Agents.AI.A2A\Microsoft.Agents.AI.A2A.csproj" />
+  </ItemGroup>
+
+</Project>

dotnet/samples/02-agents/A2A/A2AAgent_ProtocolSelection/Program.cs

@@ -0,0 +1,36 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+// This sample demonstrates how to select the A2A protocol binding (HTTP+JSON vs JSON-RPC) when
+// creating an AIAgent from an A2A agent card using A2AClientOptions.PreferredBindings.
+
+using A2A;
+using Microsoft.Agents.AI;
+
+var a2aAgentHost = Environment.GetEnvironmentVariable("A2A_AGENT_HOST") ?? throw new InvalidOperationException("A2A_AGENT_HOST is not set.");
+
+// Initialize an A2ACardResolver to get an A2A agent card.
+A2ACardResolver agentCardResolver = new(new Uri(a2aAgentHost));
+
+// Get the agent card
+AgentCard agentCard = await agentCardResolver.GetAgentCardAsync();
+
+// Use A2AClientOptions to explicitly select the HTTP+JSON protocol binding.
+// This tells the A2A client factory to prefer the HTTP+JSON interface when the agent card
+// advertises multiple supported interfaces.
+A2AClientOptions options = new()
+{
+    PreferredBindings = [ProtocolBindingNames.HttpJson]
+};
+
+// To prefer JSON-RPC instead, use:
+// A2AClientOptions options = new()
+// {
+//     PreferredBindings = [ProtocolBindingNames.JsonRpc]
+// };
+
+// Create an instance of the AIAgent for an existing A2A agent, using the specified protocol binding.
+AIAgent agent = agentCard.AsAIAgent(options: options);
+
+// Invoke the agent and output the text result.
+AgentResponse response = await agent.RunAsync("Tell me a joke about a pirate.");
+Console.WriteLine(response);

dotnet/samples/02-agents/A2A/A2AAgent_ProtocolSelection/README.md

@@ -0,0 +1,27 @@
+# A2A Agent Protocol Selection
+
+This sample demonstrates how to select the A2A protocol binding when creating an `AIAgent` from an A2A agent card.
+
+A2A agents can expose multiple interfaces with different protocol bindings (e.g., HTTP+JSON, JSON-RPC). By default, `AsAIAgent()` prefers HTTP+JSON with JSON-RPC as a fallback. This sample shows how to use `A2AClientOptions.PreferredBindings` to explicitly control which protocol binding is used.
+
+The sample:
+
+- Connects to an A2A agent server specified in the `A2A_AGENT_HOST` environment variable
+- Configures `A2AClientOptions` to prefer the HTTP+JSON protocol binding
+- Creates an `AIAgent` from the resolved agent card using the specified binding
+- Sends a message to the agent and displays the response
+
+## Prerequisites
+
+Before you begin, ensure you have the following prerequisites:
+
+- .NET 10.0 SDK or later
+- An A2A agent server running and accessible via HTTP
+
+**Note**: These samples need to be run against a valid A2A server. If no A2A server is available, they can be run against the echo-agent that can be spun up locally by following the guidelines at: https://github.com/a2aproject/a2a-dotnet/blob/main/samples/AgentServer/README.md
+
+Set the following environment variable:
+
+```powershell
+$env:A2A_AGENT_HOST="http://localhost:5000"  # Replace with your A2A agent server host
+```

dotnet/samples/02-agents/A2A/A2AAgent_StreamReconnection/A2AAgent_StreamReconnection.csproj

@@ -0,0 +1,23 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFrameworks>net10.0</TargetFrameworks>
+
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="A2A" />
+    <PackageReference Include="Azure.AI.OpenAI" />
+    <PackageReference Include="Azure.Identity" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\..\src\Microsoft.Agents.AI.A2A\Microsoft.Agents.AI.A2A.csproj" />
+    <ProjectReference Include="..\..\..\..\src\Microsoft.Agents.AI.OpenAI\Microsoft.Agents.AI.OpenAI.csproj" />
+  </ItemGroup>
+
+</Project>

dotnet/samples/02-agents/A2A/A2AAgent_StreamReconnection/Program.cs

@@ -0,0 +1,55 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+// This sample demonstrates how to reconnect to an A2A agent's streaming response using continuation tokens,
+// allowing recovery from stream interruptions without losing progress.
+
+using A2A;
+using Microsoft.Agents.AI;
+using Microsoft.Extensions.AI;
+
+var a2aAgentHost = Environment.GetEnvironmentVariable("A2A_AGENT_HOST") ?? throw new InvalidOperationException("A2A_AGENT_HOST is not set.");
+
+// Initialize an A2ACardResolver to get an A2A agent card.
+A2ACardResolver agentCardResolver = new(new Uri(a2aAgentHost));
+
+// Get the agent card
+AgentCard agentCard = await agentCardResolver.GetAgentCardAsync();
+
+// Create an instance of the AIAgent for an existing A2A agent specified by the agent card.
+AIAgent agent = agentCard.AsAIAgent();
+
+AgentSession session = await agent.CreateSessionAsync();
+
+ResponseContinuationToken? continuationToken = null;
+
+await foreach (var update in agent.RunStreamingAsync("Conduct a comprehensive analysis of quantum computing applications in cryptography, including recent breakthroughs, implementation challenges, and future roadmap. Please include diagrams and visual representations to illustrate complex concepts.", session))
+{
+    // Saving the continuation token to be able to reconnect to the same response stream later.
+    // Note: Continuation tokens are only returned for long-running tasks. If the underlying A2A agent
+    // returns a message instead of a task, the continuation token will not be initialized.
+    // A2A agents do not support stream resumption from a specific point in the stream,
+    // but only reconnection to obtain the same response stream from the beginning.
+    // So, A2A agents will return an initialized continuation token in the first update
+    // representing the beginning of the stream, and it will be null in all subsequent updates.
+    if (update.ContinuationToken is { } token)
+    {
+        continuationToken = token;
+    }
+
+    // Imitating stream interruption
+    break;
+}
+
+// Reconnect to the same response stream using the continuation token obtained from the previous run.
+// As a first update, the agent will return an update representing the current state of the response at the moment of calling
+// RunStreamingAsync with the same continuation token, followed by other updates until the end of the stream is reached.
+if (continuationToken is not null)
+{
+    await foreach (var update in agent.RunStreamingAsync(session, options: new() { ContinuationToken = continuationToken }))
+    {
+        if (!string.IsNullOrEmpty(update.Text))
+        {
+            Console.WriteLine(update.Text);
+        }
+    }
+}

dotnet/samples/02-agents/A2A/A2AAgent_StreamReconnection/README.md

@@ -0,0 +1,29 @@
+# A2A Agent Stream Reconnection
+
+This sample demonstrates how to reconnect to an A2A agent's streaming response using continuation tokens, allowing recovery from stream interruptions without losing progress.
+
+The sample:
+
+- Connects to an A2A agent server specified in the `A2A_AGENT_HOST` environment variable
+- Sends a request to the agent and begins streaming the response
+- Captures a continuation token from the stream for later reconnection
+- Simulates a stream interruption by breaking out of the streaming loop
+- Reconnects to the same response stream using the captured continuation token
+- Displays the response received after reconnection
+
+This pattern is useful when network interruptions or other failures may disrupt an ongoing streaming response, and you need to recover and continue processing.
+
+> **Note:** Continuation tokens are only available when the underlying A2A agent returns a task. If the agent returns a message instead, the continuation token will not be initialized and stream reconnection is not applicable.
+
+# Prerequisites
+
+Before you begin, ensure you have the following prerequisites:
+
+- .NET 10.0 SDK or later
+- An A2A agent server running and accessible via HTTP
+
+Set the following environment variable:
+
+```powershell
+$env:A2A_AGENT_HOST="http://localhost:5000"  # Replace with your A2A agent server host
+```

dotnet/samples/02-agents/A2A/README.md

@@ -3,7 +3,7 @@
 These samples demonstrate how to work with Agent-to-Agent (A2A) specific features in the Agent Framework.
 
 For other samples that demonstrate how to use AIAgent instances,
-see the [Getting Started With Agents](../../02-agents/Agents/README.md) samples.
+see the [Getting Started With Agents](../Agents/README.md) samples.
 
 ## Prerequisites
 
@@ -15,6 +15,8 @@ See the README.md for each sample for the prerequisites for that sample.
 |---|---|
 |[A2A Agent As Function Tools](./A2AAgent_AsFunctionTools/)|This sample demonstrates how to represent an A2A agent as a set of function tools, where each function tool corresponds to a skill of the A2A agent, and register these function tools with another AI agent so it can leverage the A2A agent's skills.|
 |[A2A Agent Polling For Task Completion](./A2AAgent_PollingForTaskCompletion/)|This sample demonstrates how to poll for long-running task completion using continuation tokens with an A2A agent.|
+|[A2A Agent Stream Reconnection](./A2AAgent_StreamReconnection/)|This sample demonstrates how to reconnect to an A2A agent's streaming response using continuation tokens, allowing recovery from stream interruptions.|
+|[A2A Agent Protocol Selection](./A2AAgent_ProtocolSelection/)|This sample demonstrates how to select the A2A protocol binding (HTTP+JSON vs JSON-RPC) when creating an AIAgent from an A2A agent card using A2AClientOptions.|
 
 ## Running the samples from the console
 

dotnet/samples/02-agents/README.md

@@ -19,3 +19,4 @@ The getting started samples demonstrate the fundamental concepts and functionali
 | [Declarative Agents](./DeclarativeAgents) | Loading and executing AI agents from YAML configuration files |
 | [AG-UI](./AGUI/README.md) | Getting started with AG-UI (Agent UI Protocol) servers and clients |
 | [Dev UI](./DevUI/README.md) | Interactive web interface for testing and debugging AI agents during development |
+| [A2A Agents](./A2A/README.md) | Working with Agent-to-Agent (A2A) specific features |

dotnet/samples/05-end-to-end/A2AClientServer/A2AClient/Program.cs

@@ -62,12 +62,10 @@ public static class Program
                 }
 
                 var agentResponse = await hostAgent.Agent!.RunAsync(message, session, cancellationToken: cancellationToken);
-                foreach (var chatMessage in agentResponse.Messages)
-                {
-                    Console.ForegroundColor = ConsoleColor.Cyan;
-                    Console.WriteLine($"\nAgent: {chatMessage.Text}");
-                    Console.ResetColor();
-                }
+
+                Console.ForegroundColor = ConsoleColor.Cyan;
+                Console.WriteLine($"\nAgent: {agentResponse.Text}");
+                Console.ResetColor();
             }
         }
         catch (Exception ex)

dotnet/samples/05-end-to-end/A2AClientServer/A2AServer/HostAgentFactory.cs

@@ -14,7 +14,7 @@ namespace A2AServer;
 
 internal static class HostAgentFactory
 {
-    internal static async Task<(AIAgent, AgentCard)> CreateFoundryHostAgentAsync(string agentType, string model, string endpoint, string agentName, IList<AITool>? tools = null)
+    internal static async Task<(AIAgent, AgentCard)> CreateFoundryHostAgentAsync(string agentType, string model, string endpoint, string agentName, string[] agentUrls, IList<AITool>? tools = null)
     {
         // WARNING: DefaultAzureCredential is convenient for development but requires careful consideration in production.
         // In production, consider using a specific credential (e.g., ManagedIdentityCredential) to avoid
@@ -26,16 +26,16 @@ internal static class HostAgentFactory
 
         AgentCard agentCard = agentType.ToUpperInvariant() switch
         {
-            "INVOICE" => GetInvoiceAgentCard(),
-            "POLICY" => GetPolicyAgentCard(),
-            "LOGISTICS" => GetLogisticsAgentCard(),
+            "INVOICE" => GetInvoiceAgentCard(agentUrls),
+            "POLICY" => GetPolicyAgentCard(agentUrls),
+            "LOGISTICS" => GetLogisticsAgentCard(agentUrls),
             _ => throw new ArgumentException($"Unsupported agent type: {agentType}"),
         };
 
         return new(agent, agentCard);
     }
 
-    internal static async Task<(AIAgent, AgentCard)> CreateChatCompletionHostAgentAsync(string agentType, string model, string apiKey, string name, string instructions, IList<AITool>? tools = null)
+    internal static async Task<(AIAgent, AgentCard)> CreateChatCompletionHostAgentAsync(string agentType, string model, string apiKey, string name, string instructions, string[] agentUrls, IList<AITool>? tools = null)
     {
         AIAgent agent = new OpenAIClient(apiKey)
              .GetChatClient(model)
@@ -43,9 +43,9 @@ internal static class HostAgentFactory
 
         AgentCard agentCard = agentType.ToUpperInvariant() switch
         {
-            "INVOICE" => GetInvoiceAgentCard(),
-            "POLICY" => GetPolicyAgentCard(),
-            "LOGISTICS" => GetLogisticsAgentCard(),
+            "INVOICE" => GetInvoiceAgentCard(agentUrls),
+            "POLICY" => GetPolicyAgentCard(agentUrls),
+            "LOGISTICS" => GetLogisticsAgentCard(agentUrls),
             _ => throw new ArgumentException($"Unsupported agent type: {agentType}"),
         };
 
@@ -53,7 +53,7 @@ internal static class HostAgentFactory
     }
 
     #region private
-    private static AgentCard GetInvoiceAgentCard()
+    private static AgentCard GetInvoiceAgentCard(string[] agentUrls)
     {
         var capabilities = new AgentCapabilities()
         {
@@ -82,10 +82,11 @@ internal static class HostAgentFactory
             DefaultOutputModes = ["text"],
             Capabilities = capabilities,
             Skills = [invoiceQuery],
+            SupportedInterfaces = CreateAgentInterfaces(agentUrls)
         };
     }
 
-    private static AgentCard GetPolicyAgentCard()
+    private static AgentCard GetPolicyAgentCard(string[] agentUrls)
     {
         var capabilities = new AgentCapabilities()
         {
@@ -114,10 +115,11 @@ internal static class HostAgentFactory
             DefaultOutputModes = ["text"],
             Capabilities = capabilities,
             Skills = [policyQuery],
+            SupportedInterfaces = CreateAgentInterfaces(agentUrls)
         };
     }
 
-    private static AgentCard GetLogisticsAgentCard()
+    private static AgentCard GetLogisticsAgentCard(string[] agentUrls)
     {
         var capabilities = new AgentCapabilities()
         {
@@ -146,7 +148,29 @@ internal static class HostAgentFactory
             DefaultOutputModes = ["text"],
             Capabilities = capabilities,
             Skills = [logisticsQuery],
+            SupportedInterfaces = CreateAgentInterfaces(agentUrls)
         };
     }
+
+    private static List<AgentInterface> CreateAgentInterfaces(string[] agentUrls)
+    {
+        List<AgentInterface> agentInterfaces = [];
+
+        agentInterfaces.AddRange(agentUrls.Select(url => new AgentInterface
+        {
+            Url = url,
+            ProtocolBinding = ProtocolBindingNames.JsonRpc,
+            ProtocolVersion = "1.0",
+        }));
+
+        agentInterfaces.AddRange(agentUrls.Select(url => new AgentInterface
+        {
+            Url = url,
+            ProtocolBinding = ProtocolBindingNames.HttpJson,
+            ProtocolVersion = "1.0",
+        }));
+
+        return agentInterfaces;
+    }
     #endregion
 }

dotnet/samples/05-end-to-end/A2AClientServer/A2AServer/Program.cs

@@ -25,10 +25,6 @@ for (var i = 0; i < args.Length; i++)
 
 var builder = WebApplication.CreateBuilder(args);
 builder.Services.AddHttpClient().AddLogging();
-var app = builder.Build();
-
-var httpClient = app.Services.GetRequiredService<IHttpClientFactory>().CreateClient();
-var logger = app.Logger;
 
 IConfigurationRoot configuration = new ConfigurationBuilder()
     .AddEnvironmentVariables()
@@ -38,14 +34,15 @@ IConfigurationRoot configuration = new ConfigurationBuilder()
 string? apiKey = configuration["OPENAI_API_KEY"];
 string model = configuration["OPENAI_CHAT_MODEL_NAME"] ?? "gpt-5.4-mini";
 string? endpoint = configuration["AZURE_AI_PROJECT_ENDPOINT"];
+string[] agentUrls = (builder.Configuration["urls"] ?? "http://localhost:5000").Split(';');
 
 var invoiceQueryPlugin = new InvoiceQuery();
 IList<AITool> tools =
-    [
+[
     AIFunctionFactory.Create(invoiceQueryPlugin.QueryInvoices),
     AIFunctionFactory.Create(invoiceQueryPlugin.QueryByTransactionId),
     AIFunctionFactory.Create(invoiceQueryPlugin.QueryByInvoiceId)
-    ];
+];
 
 AIAgent hostA2AAgent;
 AgentCard hostA2AAgentCard;
@@ -54,9 +51,9 @@ if (!string.IsNullOrEmpty(endpoint) && !string.IsNullOrEmpty(agentName))
 {
     (hostA2AAgent, hostA2AAgentCard) = agentType.ToUpperInvariant() switch
     {
-        "INVOICE" => await HostAgentFactory.CreateFoundryHostAgentAsync(agentType, model, endpoint, agentName, tools),
-        "POLICY" => await HostAgentFactory.CreateFoundryHostAgentAsync(agentType, model, endpoint, agentName),
-        "LOGISTICS" => await HostAgentFactory.CreateFoundryHostAgentAsync(agentType, model, endpoint, agentName),
+        "INVOICE" => await HostAgentFactory.CreateFoundryHostAgentAsync(agentType, model, endpoint, agentName, agentUrls, tools),
+        "POLICY" => await HostAgentFactory.CreateFoundryHostAgentAsync(agentType, model, endpoint, agentName, agentUrls),
+        "LOGISTICS" => await HostAgentFactory.CreateFoundryHostAgentAsync(agentType, model, endpoint, agentName, agentUrls),
         _ => throw new ArgumentException($"Unsupported agent type: {agentType}"),
     };
 }
@@ -68,7 +65,7 @@ else if (!string.IsNullOrEmpty(apiKey))
             agentType, model, apiKey, "InvoiceAgent",
             """
             You specialize in handling queries related to invoices.
-            """, tools),
+            """, agentUrls, tools),
         "POLICY" => await HostAgentFactory.CreateChatCompletionHostAgentAsync(
             agentType, model, apiKey, "PolicyAgent",
             """
@@ -84,7 +81,7 @@ else if (!string.IsNullOrEmpty(apiKey))
             resolution in SAP CRM and notify the customer via email within 2 business days, referencing the
             original invoice and the credit memo number. Use the 'Formal Credit Notification' email
             template."
-            """),
+            """, agentUrls),
         "LOGISTICS" => await HostAgentFactory.CreateChatCompletionHostAgentAsync(
             agentType, model, apiKey, "LogisticsAgent",
             """
@@ -95,7 +92,7 @@ else if (!string.IsNullOrEmpty(apiKey))
             Shipment number: SHPMT-SAP-001
             Item: TSHIRT-RED-L
             Quantity: 900
-            """),
+            """, agentUrls),
         _ => throw new ArgumentException($"Unsupported agent type: {agentType}"),
     };
 }
@@ -104,10 +101,12 @@ else
     throw new ArgumentException("Either A2AServer:ApiKey or A2AServer:ConnectionString & agentName must be provided");
 }
 
-var a2aTaskManager = app.MapA2A(
-    hostA2AAgent,
-    path: "/",
-    agentCard: hostA2AAgentCard,
-    taskManager => app.MapWellKnownAgentCard(taskManager, "/"));
+builder.AddA2AServer(hostA2AAgent);
+
+var app = builder.Build();
+app.MapA2AHttpJson(hostA2AAgent, "/");
+app.MapA2AJsonRpc(hostA2AAgent, "/");
+
+app.MapWellKnownAgentCard(hostA2AAgentCard);
 
 await app.RunAsync();

dotnet/samples/05-end-to-end/AgentWebChat/AgentWebChat.AgentHost/Program.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Microsoft. All rights reserved.
 
-using A2A.AspNetCore;
 using AgentWebChat.AgentHost;
 using AgentWebChat.AgentHost.Custom;
 using AgentWebChat.AgentHost.Utilities;
@@ -146,6 +145,9 @@ builder.Services.AddKeyedSingleton<AIAgent>("my-di-matchingname-agent", (sp, nam
         instructions: "you are a dependency inject agent. Tell me all about dependency injection.");
 });
 
+pirateAgentBuilder.AddA2AServer();
+knightsKnavesAgentBuilder.AddA2AServer();
+
 var app = builder.Build();
 
 app.MapOpenApi();
@@ -154,17 +156,9 @@ app.UseSwaggerUI(options => options.SwaggerEndpoint("/openapi/v1.json", "Agents
 // Configure the HTTP request pipeline.
 app.UseExceptionHandler();
 
-// attach a2a with simple message communication
-app.MapA2A(pirateAgentBuilder, path: "/a2a/pirate");
-app.MapA2A(knightsKnavesAgentBuilder, path: "/a2a/knights-and-knaves", agentCard: new()
-{
-    Name = "Knights and Knaves",
-    Description = "An agent that helps you solve the knights and knaves puzzle.",
-    Version = "1.0",
-
-    // Url can be not set, and SDK will help assign it.
-    // Url = "http://localhost:5390/a2a/knights-and-knaves"
-});
+// Expose A2A servers over HTTP with JSON payloads
+app.MapA2AHttpJson(pirateAgentBuilder, path: "/a2a/pirate");
+app.MapA2AHttpJson(knightsKnavesAgentBuilder, path: "/a2a/knights-and-knaves");
 
 app.MapDevUI();
 

dotnet/samples/05-end-to-end/AgentWebChat/AgentWebChat.Web/A2AAgentClient.cs

@@ -43,20 +43,21 @@ internal sealed class A2AAgentClient : AgentClientBase
         {
             // Convert all messages to A2A parts and create a single message
             var parts = messages.ToParts();
-            var a2aMessage = new AgentMessage
+            var a2aMessage = new Message
             {
                 MessageId = Guid.NewGuid().ToString("N"),
                 ContextId = contextId,
-                Role = MessageRole.User,
+                Role = Role.User,
                 Parts = parts
             };
 
-            var messageSendParams = new MessageSendParams { Message = a2aMessage };
+            var messageSendParams = new SendMessageRequest { Message = a2aMessage };
             var a2aResponse = await a2aClient.SendMessageAsync(messageSendParams, cancellationToken);
 
             // Handle different response types
-            if (a2aResponse is AgentMessage message)
+            if (a2aResponse.PayloadCase == SendMessageResponseCase.Message)
             {
+                var message = a2aResponse.Message!;
                 var responseMessage = message.ToChatMessage();
                 if (responseMessage is { Contents.Count: > 0 })
                 {
@@ -67,9 +68,10 @@ internal sealed class A2AAgentClient : AgentClientBase
                     });
                 }
             }
-            else if (a2aResponse is AgentTask agentTask)
+            else if (a2aResponse.PayloadCase == SendMessageResponseCase.Task)
             {
                 // Manually convert AgentTask artifacts to ChatMessages since the extension method is internal
+                var agentTask = a2aResponse.Task!;
                 if (agentTask.Artifacts is not null)
                 {
                     foreach (var artifact in agentTask.Artifacts)

dotnet/samples/README.md

@@ -16,7 +16,7 @@ were local agents. These are supported using various `AIAgent` subclasses.
 | [`01-get-started/`](./01-get-started/) | Progressive tutorial: hello agent → hosting |
 | [`02-agents/`](./02-agents/) | Deep-dive by concept: tools, middleware, providers, orchestrations |
 | [`03-workflows/`](./03-workflows/) | Workflow patterns: sequential, concurrent, state, declarative |
-| [`04-hosting/`](./04-hosting/) | Deployment: Azure Functions, Durable Tasks, A2A |
+| [`04-hosting/`](./04-hosting/) | Deployment: Azure Functions, Durable Tasks |
 | [`05-end-to-end/`](./05-end-to-end/) | Full applications, evaluation, demos |
 
 ## Getting Started

dotnet/src/Microsoft.Agents.AI.A2A/A2AAgent.cs

@@ -3,7 +3,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Net.ServerSentEvents;
 using System.Runtime.CompilerServices;
 using System.Text.Json;
 using System.Threading;
@@ -28,7 +27,7 @@ public sealed class A2AAgent : AIAgent
 {
     private static readonly AIAgentMetadata s_agentMetadata = new("a2a");
 
-    private readonly A2AClient _a2aClient;
+    private readonly IA2AClient _a2aClient;
     private readonly string? _id;
     private readonly string? _name;
     private readonly string? _description;
@@ -42,7 +41,7 @@ public sealed class A2AAgent : AIAgent
     /// <param name="name">The the name of the agent.</param>
     /// <param name="description">The description of the agent.</param>
     /// <param name="loggerFactory">Optional logger factory to use for logging.</param>
-    public A2AAgent(A2AClient a2aClient, string? id = null, string? name = null, string? description = null, ILoggerFactory? loggerFactory = null)
+    public A2AAgent(IA2AClient a2aClient, string? id = null, string? name = null, string? description = null, ILoggerFactory? loggerFactory = null)
     {
         _ = Throw.IfNull(a2aClient);
 
@@ -100,64 +99,47 @@ public sealed class A2AAgent : AIAgent
 
         this._logger.LogA2AAgentInvokingAgent(nameof(RunAsync), this.Id, this.Name);
 
-        A2AResponse? a2aResponse = null;
-
         if (GetContinuationToken(messages, options) is { } token)
         {
-            a2aResponse = await this._a2aClient.GetTaskAsync(token.TaskId, cancellationToken).ConfigureAwait(false);
-        }
-        else
-        {
-            MessageSendParams sendParams = new()
-            {
-                Message = CreateA2AMessage(typedSession, messages),
-                Metadata = options?.AdditionalProperties?.ToA2AMetadata()
-            };
+            AgentTask agentTask = await this._a2aClient.GetTaskAsync(new GetTaskRequest { Id = token.TaskId }, cancellationToken).ConfigureAwait(false);
 
-            a2aResponse = await this._a2aClient.SendMessageAsync(sendParams, cancellationToken).ConfigureAwait(false);
+            this._logger.LogAgentChatClientInvokedAgent(nameof(RunAsync), this.Id, this.Name);
+
+            UpdateSession(typedSession, agentTask.ContextId, agentTask.Id);
+
+            return this.ConvertToAgentResponse(agentTask);
         }
 
+        SendMessageRequest sendParams = new()
+        {
+            Message = CreateA2AMessage(typedSession, messages),
+            Metadata = options?.AdditionalProperties?.ToA2AMetadata(),
+            Configuration = new SendMessageConfiguration { ReturnImmediately = options?.AllowBackgroundResponses is true }
+        };
+
+        SendMessageResponse a2aResponse = await this._a2aClient.SendMessageAsync(sendParams, cancellationToken).ConfigureAwait(false);
+
         this._logger.LogAgentChatClientInvokedAgent(nameof(RunAsync), this.Id, this.Name);
 
-        if (a2aResponse is AgentMessage message)
+        if (a2aResponse.PayloadCase == SendMessageResponseCase.Message)
         {
+            var message = a2aResponse.Message!;
+
             UpdateSession(typedSession, message.ContextId);
 
-            return new AgentResponse
-            {
-                AgentId = this.Id,
-                ResponseId = message.MessageId,
-                FinishReason = ChatFinishReason.Stop,
-                RawRepresentation = message,
-                Messages = [message.ToChatMessage()],
-                AdditionalProperties = message.Metadata?.ToAdditionalProperties(),
-            };
+            return this.ConvertToAgentResponse(message);
         }
 
-        if (a2aResponse is AgentTask agentTask)
+        if (a2aResponse.PayloadCase == SendMessageResponseCase.Task)
         {
+            var agentTask = a2aResponse.Task!;
+
             UpdateSession(typedSession, agentTask.ContextId, agentTask.Id);
 
-            var response = new AgentResponse
-            {
-                AgentId = this.Id,
-                ResponseId = agentTask.Id,
-                FinishReason = MapTaskStateToFinishReason(agentTask.Status.State),
-                RawRepresentation = agentTask,
-                Messages = agentTask.ToChatMessages() ?? [],
-                ContinuationToken = CreateContinuationToken(agentTask.Id, agentTask.Status.State),
-                AdditionalProperties = agentTask.Metadata?.ToAdditionalProperties(),
-            };
-
-            if (agentTask.ToChatMessages() is { Count: > 0 } taskMessages)
-            {
-                response.Messages = taskMessages;
-            }
-
-            return response;
+            return this.ConvertToAgentResponse(agentTask);
         }
 
-        throw new NotSupportedException($"Only Message and AgentTask responses are supported from A2A agents. Received: {a2aResponse.GetType().FullName ?? "null"}");
+        throw new NotSupportedException($"Only Message and AgentTask responses are supported from A2A agents. Received: {a2aResponse.PayloadCase}");
     }
 
     /// <inheritdoc/>
@@ -169,59 +151,61 @@ public sealed class A2AAgent : AIAgent
 
         this._logger.LogA2AAgentInvokingAgent(nameof(RunStreamingAsync), this.Id, this.Name);
 
-        ConfiguredCancelableAsyncEnumerable<SseItem<A2AEvent>> a2aSseEvents;
+        ConfiguredCancelableAsyncEnumerable<StreamResponse> streamEvents;
 
-        if (options?.ContinuationToken is not null)
+        if (GetContinuationToken(messages, options) is { } token)
         {
-            // Task stream resumption is not well defined in the A2A v2.* specification, leaving it to the agent implementations.  
-            // The v3.0 specification improves this by defining task stream reconnection that allows obtaining the same stream  
-            // from the beginning, but it does not define stream resumption from a specific point in the stream.  
-            // Therefore, the code should be updated once the A2A .NET library supports the A2A v3.0 specification,  
-            // and AF has the necessary model to allow consumers to know whether they need to resume the stream and add new updates to  
-            // the existing ones or reconnect the stream and obtain all updates again.  
-            // For more details, see the following issue: https://github.com/microsoft/agent-framework/issues/1764  
-            throw new InvalidOperationException("Reconnecting to task streams using continuation tokens is not supported yet.");
-            // a2aSseEvents = this._a2aClient.SubscribeToTaskAsync(token.TaskId, cancellationToken).ConfigureAwait(false);  
+            streamEvents = this.SubscribeToTaskWithFallbackAsync(token.TaskId, cancellationToken).ConfigureAwait(false);
         }
-
-        MessageSendParams sendParams = new()
+        else
         {
-            Message = CreateA2AMessage(typedSession, messages),
-            Metadata = options?.AdditionalProperties?.ToA2AMetadata()
-        };
+            SendMessageRequest sendParams = new()
+            {
+                Message = CreateA2AMessage(typedSession, messages),
+                Metadata = options?.AdditionalProperties?.ToA2AMetadata()
+            };
 
-        a2aSseEvents = this._a2aClient.SendMessageStreamingAsync(sendParams, cancellationToken).ConfigureAwait(false);
+            streamEvents = this._a2aClient.SendStreamingMessageAsync(sendParams, cancellationToken).ConfigureAwait(false);
+        }
 
         this._logger.LogAgentChatClientInvokedAgent(nameof(RunStreamingAsync), this.Id, this.Name);
 
         string? contextId = null;
         string? taskId = null;
 
-        await foreach (var sseEvent in a2aSseEvents)
+        await foreach (var streamResponse in streamEvents)
         {
-            if (sseEvent.Data is AgentMessage message)
+            switch (streamResponse.PayloadCase)
             {
-                contextId = message.ContextId;
+                case StreamResponseCase.Message:
+                    var message = streamResponse.Message!;
+                    contextId = message.ContextId;
+                    yield return this.ConvertToAgentResponseUpdate(message);
+                    break;
 
-                yield return this.ConvertToAgentResponseUpdate(message);
-            }
-            else if (sseEvent.Data is AgentTask task)
-            {
-                contextId = task.ContextId;
-                taskId = task.Id;
+                case StreamResponseCase.Task:
+                    var task = streamResponse.Task!;
+                    contextId = task.ContextId;
+                    taskId = task.Id;
+                    yield return this.ConvertToAgentResponseUpdate(task);
+                    break;
 
-                yield return this.ConvertToAgentResponseUpdate(task);
-            }
-            else if (sseEvent.Data is TaskUpdateEvent taskUpdateEvent)
-            {
-                contextId = taskUpdateEvent.ContextId;
-                taskId = taskUpdateEvent.TaskId;
+                case StreamResponseCase.StatusUpdate:
+                    var statusUpdate = streamResponse.StatusUpdate!;
+                    contextId = statusUpdate.ContextId;
+                    taskId = statusUpdate.TaskId;
+                    yield return this.ConvertToAgentResponseUpdate(statusUpdate);
+                    break;
 
-                yield return this.ConvertToAgentResponseUpdate(taskUpdateEvent);
-            }
-            else
-            {
-                throw new NotSupportedException($"Only message, task, task update events are supported from A2A agents. Received: {sseEvent.Data.GetType().FullName ?? "null"}");
+                case StreamResponseCase.ArtifactUpdate:
+                    var artifactUpdate = streamResponse.ArtifactUpdate!;
+                    contextId = artifactUpdate.ContextId;
+                    taskId = artifactUpdate.TaskId;
+                    yield return this.ConvertToAgentResponseUpdate(artifactUpdate);
+                    break;
+
+                default:
+                    throw new NotSupportedException($"Only message, task, task update events are supported from A2A agents. Received: {streamResponse.PayloadCase}");
             }
         }
 
@@ -240,7 +224,7 @@ public sealed class A2AAgent : AIAgent
     /// <inheritdoc/>
     public override object? GetService(Type serviceType, object? serviceKey = null)
         => base.GetService(serviceType, serviceKey)
-           ?? (serviceType == typeof(A2AClient) ? this._a2aClient
+           ?? (serviceType == typeof(IA2AClient) ? this._a2aClient
             : serviceType == typeof(AIAgentMetadata) ? s_agentMetadata
             : null);
 
@@ -264,6 +248,75 @@ public sealed class A2AAgent : AIAgent
         return typedSession;
     }
 
+    /// <summary>
+    /// Subscribes to task updates, falling back to <see cref="A2AClient.GetTaskAsync"/>
+    /// when the task has already reached a terminal state and the server responds with
+    /// <see cref="A2AErrorCode.UnsupportedOperation"/>.
+    /// </summary>
+    /// <remarks>
+    /// Per A2A spec §3.1.6, subscribing to a task in a terminal state (completed, failed,
+    /// canceled, or rejected) results in an <c>UnsupportedOperationError</c>.
+    /// See: <see href="https://a2a-protocol.org/latest/specification/#332-error-handling"/>.
+    /// </remarks>
+    private async IAsyncEnumerable<StreamResponse> SubscribeToTaskWithFallbackAsync(
+        string taskId,
+        [EnumeratorCancellation] CancellationToken cancellationToken)
+    {
+        var subscribeStream = this._a2aClient.SubscribeToTaskAsync(new SubscribeToTaskRequest { Id = taskId }, cancellationToken);
+
+        var enumerator = subscribeStream.GetAsyncEnumerator(cancellationToken);
+
+        // yield return cannot appear inside a try block that has catch clauses,
+        // so we manually advance the enumerator within try/catch and yield outside it.
+        // The outer try/finally (no catch) is allowed to contain yield return in C#.
+        StreamResponse? fallbackResponse = null;
+        bool disposed = false;
+
+        try
+        {
+            while (true)
+            {
+                bool hasNext;
+                try
+                {
+                    hasNext = await enumerator.MoveNextAsync().ConfigureAwait(false);
+                }
+                catch (A2AException ex) when (ex.ErrorCode == A2AErrorCode.UnsupportedOperation)
+                {
+                    this._logger.LogA2ASubscribeToTaskFallback(this.Id, this.Name, taskId, ex.Message);
+
+                    // Dispose the enumerator before the fallback call to release the HTTP/SSE connection.
+                    await enumerator.DisposeAsync().ConfigureAwait(false);
+                    disposed = true;
+
+                    AgentTask agentTask = await this._a2aClient.GetTaskAsync(new GetTaskRequest { Id = taskId }, cancellationToken).ConfigureAwait(false);
+
+                    fallbackResponse = new StreamResponse { Task = agentTask };
+                    break;
+                }
+
+                if (!hasNext)
+                {
+                    break;
+                }
+
+                yield return enumerator.Current;
+            }
+
+            if (fallbackResponse is not null)
+            {
+                yield return fallbackResponse;
+            }
+        }
+        finally
+        {
+            if (!disposed)
+            {
+                await enumerator.DisposeAsync().ConfigureAwait(false);
+            }
+        }
+    }
+
     private static void UpdateSession(A2AAgentSession? session, string? contextId, string? taskId = null)
     {
         if (session is null)
@@ -284,7 +337,7 @@ public sealed class A2AAgent : AIAgent
         session.TaskId = taskId;
     }
 
-    private static AgentMessage CreateA2AMessage(A2AAgentSession typedSession, IEnumerable<ChatMessage> messages)
+    private static Message CreateA2AMessage(A2AAgentSession typedSession, IEnumerable<ChatMessage> messages)
     {
         var a2aMessage = messages.ToA2AMessage();
 
@@ -324,7 +377,34 @@ public sealed class A2AAgent : AIAgent
         return null;
     }
 
-    private AgentResponseUpdate ConvertToAgentResponseUpdate(AgentMessage message)
+    private AgentResponse ConvertToAgentResponse(Message message)
+    {
+        return new AgentResponse
+        {
+            AgentId = this.Id,
+            ResponseId = message.MessageId,
+            FinishReason = ChatFinishReason.Stop,
+            RawRepresentation = message,
+            Messages = [message.ToChatMessage()],
+            AdditionalProperties = message.Metadata?.ToAdditionalProperties(),
+        };
+    }
+
+    private AgentResponse ConvertToAgentResponse(AgentTask task)
+    {
+        return new AgentResponse
+        {
+            AgentId = this.Id,
+            ResponseId = task.Id,
+            FinishReason = MapTaskStateToFinishReason(task.Status.State),
+            RawRepresentation = task,
+            Messages = task.ToChatMessages() ?? [],
+            ContinuationToken = CreateContinuationToken(task.Id, task.Status.State),
+            AdditionalProperties = task.Metadata?.ToAdditionalProperties(),
+        };
+    }
+
+    private AgentResponseUpdate ConvertToAgentResponseUpdate(Message message)
     {
         return new AgentResponseUpdate
         {
@@ -349,32 +429,35 @@ public sealed class A2AAgent : AIAgent
             RawRepresentation = task,
             Role = ChatRole.Assistant,
             Contents = task.ToAIContents(),
+            ContinuationToken = CreateContinuationToken(task.Id, task.Status.State),
             AdditionalProperties = task.Metadata?.ToAdditionalProperties(),
         };
     }
 
-    private AgentResponseUpdate ConvertToAgentResponseUpdate(TaskUpdateEvent taskUpdateEvent)
+    private AgentResponseUpdate ConvertToAgentResponseUpdate(TaskStatusUpdateEvent statusUpdateEvent)
     {
-        AgentResponseUpdate responseUpdate = new()
+        return new AgentResponseUpdate
         {
             AgentId = this.Id,
-            ResponseId = taskUpdateEvent.TaskId,
-            RawRepresentation = taskUpdateEvent,
+            ResponseId = statusUpdateEvent.TaskId,
+            RawRepresentation = statusUpdateEvent,
             Role = ChatRole.Assistant,
-            AdditionalProperties = taskUpdateEvent.Metadata?.ToAdditionalProperties() ?? [],
+            FinishReason = MapTaskStateToFinishReason(statusUpdateEvent.Status.State),
+            AdditionalProperties = statusUpdateEvent.Metadata?.ToAdditionalProperties() ?? [],
         };
+    }
 
-        if (taskUpdateEvent is TaskArtifactUpdateEvent artifactUpdateEvent)
+    private AgentResponseUpdate ConvertToAgentResponseUpdate(TaskArtifactUpdateEvent artifactUpdateEvent)
+    {
+        return new AgentResponseUpdate
         {
-            responseUpdate.Contents = artifactUpdateEvent.Artifact.ToAIContents();
-            responseUpdate.RawRepresentation = artifactUpdateEvent;
-        }
-        else if (taskUpdateEvent is TaskStatusUpdateEvent statusUpdateEvent)
-        {
-            responseUpdate.FinishReason = MapTaskStateToFinishReason(statusUpdateEvent.Status.State);
-        }
-
-        return responseUpdate;
+            AgentId = this.Id,
+            ResponseId = artifactUpdateEvent.TaskId,
+            RawRepresentation = artifactUpdateEvent,
+            Role = ChatRole.Assistant,
+            Contents = artifactUpdateEvent.Artifact.ToAIContents(),
+            AdditionalProperties = artifactUpdateEvent.Metadata?.ToAdditionalProperties() ?? [],
+        };
     }
 
     private static ChatFinishReason? MapTaskStateToFinishReason(TaskState state)

dotnet/src/Microsoft.Agents.AI.A2A/A2AAgentLogMessages.cs

@@ -34,4 +34,17 @@ internal static partial class A2AAgentLogMessages
         string methodName,
         string agentId,
         string? agentName);
+
+    /// <summary>
+    /// Logs <see cref="A2AAgent"/> falling back to GetTaskAsync after SubscribeToTaskAsync failed with UnsupportedOperation.
+    /// </summary>
+    [LoggerMessage(
+        Level = LogLevel.Warning,
+        Message = "A2AAgent {AgentId}/{AgentName} SubscribeToTask for task '{TaskId}' failed with UnsupportedOperation: {ErrorMessage}. Falling back to GetTaskAsync.")]
+    public static partial void LogA2ASubscribeToTaskFallback(
+        this ILogger logger,
+        string agentId,
+        string? agentName,
+        string taskId,
+        string errorMessage);
 }

dotnet/src/Microsoft.Agents.AI.A2A/A2AContinuationToken.cs

@@ -52,7 +52,7 @@ internal class A2AContinuationToken : ResponseContinuationToken
             {
                 case "taskId":
                     reader.Read();
-                    taskId = reader.GetString()!;
+                    taskId = reader.GetString() ?? throw new JsonException("The 'taskId' property must contain a non-null string value.");
                     break;
                 default:
                     throw new JsonException($"Unrecognized property '{propertyName}'.");

dotnet/src/Microsoft.Agents.AI.A2A/Extensions/A2AAgentCardExtensions.cs

@@ -1,6 +1,5 @@
 // Copyright (c) Microsoft. All rights reserved.
 
-using System;
 using System.Net.Http;
 using Microsoft.Agents.AI;
 using Microsoft.Extensions.Logging;
@@ -25,12 +24,15 @@ public static class A2AAgentCardExtensions
     /// </remarks>
     /// <param name="card">The <see cref="AgentCard" /> to use for the agent creation.</param>
     /// <param name="httpClient">The <see cref="HttpClient"/> to use for HTTP requests.</param>
+    /// <param name="options">
+    /// Optional <see cref="A2AClientOptions"/> controlling protocol binding preference.
+    /// When not provided, defaults to preferring HTTP+JSON first, with JSON-RPC as fallback.
+    /// </param>
     /// <param name="loggerFactory">The logger factory for enabling logging within the agent.</param>
     /// <returns>An <see cref="AIAgent"/> instance backed by the A2A agent.</returns>
-    public static AIAgent AsAIAgent(this AgentCard card, HttpClient? httpClient = null, ILoggerFactory? loggerFactory = null)
+    public static AIAgent AsAIAgent(this AgentCard card, HttpClient? httpClient = null, A2AClientOptions? options = null, ILoggerFactory? loggerFactory = null)
     {
-        // Create the A2A client using the agent URL from the card.
-        var a2aClient = new A2AClient(new Uri(card.Url), httpClient);
+        var a2aClient = A2AClientFactory.Create(card, httpClient, options);
 
         return a2aClient.AsAIAgent(name: card.Name, description: card.Description, loggerFactory: loggerFactory);
     }

dotnet/src/Microsoft.Agents.AI.A2A/Extensions/A2ACardResolverExtensions.cs

@@ -34,14 +34,18 @@ public static class A2ACardResolverExtensions
     /// </remarks>
     /// <param name="resolver">The <see cref="A2ACardResolver" /> to use for the agent creation.</param>
     /// <param name="httpClient">The <see cref="HttpClient"/> to use for HTTP requests.</param>
+    /// <param name="options">
+    /// Optional <see cref="A2AClientOptions"/> controlling protocol binding preference.
+    /// When not provided, defaults to preferring HTTP+JSON first, with JSON-RPC as fallback.
+    /// </param>
     /// <param name="loggerFactory">The logger factory for enabling logging within the agent.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>An <see cref="AIAgent"/> instance backed by the A2A agent.</returns>
-    public static async Task<AIAgent> GetAIAgentAsync(this A2ACardResolver resolver, HttpClient? httpClient = null, ILoggerFactory? loggerFactory = null, CancellationToken cancellationToken = default)
+    public static async Task<AIAgent> GetAIAgentAsync(this A2ACardResolver resolver, HttpClient? httpClient = null, A2AClientOptions? options = null, ILoggerFactory? loggerFactory = null, CancellationToken cancellationToken = default)
     {
         // Obtain the agent card from the resolver.
         var agentCard = await resolver.GetAgentCardAsync(cancellationToken).ConfigureAwait(false);
 
-        return agentCard.AsAIAgent(httpClient, loggerFactory);
+        return agentCard.AsAIAgent(httpClient, options, loggerFactory);
     }
 }

dotnet/src/Microsoft.Agents.AI.A2A/Extensions/A2AClientExtensions.cs

@@ -7,7 +7,7 @@ using Microsoft.Extensions.Logging;
 namespace A2A;
 
 /// <summary>
-/// Provides extension methods for <see cref="A2AClient"/>
+/// Provides extension methods for <see cref="IA2AClient"/>
 /// to simplify the creation of A2A agents.
 /// </summary>
 /// <remarks>
@@ -29,12 +29,12 @@ public static class A2AClientExtensions
     /// <see href="https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md#3-direct-configuration--private-discovery">Direct Configuration / Private Discovery</see>
     /// discovery mechanism.
     /// </remarks>
-    /// <param name="client">The <see cref="A2AClient" /> to use for the agent.</param>
+    /// <param name="client">The <see cref="IA2AClient" /> to use for the agent.</param>
     /// <param name="id">The unique identifier for the agent.</param>
     /// <param name="name">The the name of the agent.</param>
     /// <param name="description">The description of the agent.</param>
     /// <param name="loggerFactory">Optional logger factory for enabling logging within the agent.</param>
     /// <returns>An <see cref="AIAgent"/> instance backed by the A2A agent.</returns>
-    public static AIAgent AsAIAgent(this A2AClient client, string? id = null, string? name = null, string? description = null, ILoggerFactory? loggerFactory = null) =>
+    public static AIAgent AsAIAgent(this IA2AClient client, string? id = null, string? name = null, string? description = null, ILoggerFactory? loggerFactory = null) =>
         new A2AAgent(client, id, name, description, loggerFactory);
 }

dotnet/src/Microsoft.Agents.AI.A2A/Extensions/ChatMessageExtensions.cs

@@ -11,7 +11,7 @@ namespace Microsoft.Extensions.AI;
 /// </summary>
 internal static class ChatMessageExtensions
 {
-    internal static AgentMessage ToA2AMessage(this IEnumerable<ChatMessage> messages)
+    internal static Message ToA2AMessage(this IEnumerable<ChatMessage> messages)
     {
         List<Part> allParts = [];
 
@@ -23,10 +23,10 @@ internal static class ChatMessageExtensions
             }
         }
 
-        return new AgentMessage
+        return new Message
         {
             MessageId = Guid.NewGuid().ToString("N"),
-            Role = MessageRole.User,
+            Role = Role.User,
             Parts = allParts,
         };
     }

dotnet/src/Microsoft.Agents.AI.A2A/Microsoft.Agents.AI.A2A.csproj

@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
+    <TargetFrameworks>$(TargetFrameworksCore)</TargetFrameworks>
     <VersionSuffix>preview</VersionSuffix>
     <NoWarn>$(NoWarn);MEAI001</NoWarn>
   </PropertyGroup>

dotnet/src/Microsoft.Agents.AI.Hosting.A2A.AspNetCore/A2AEndpointRouteBuilderExtensions.cs

@@ -0,0 +1,138 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Diagnostics.CodeAnalysis;
+using A2A;
+using A2A.AspNetCore;
+using Microsoft.Agents.AI;
+using Microsoft.Agents.AI.Hosting;
+using Microsoft.AspNetCore.Routing;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Shared.DiagnosticIds;
+
+namespace Microsoft.AspNetCore.Builder;
+
+/// <summary>
+/// Provides extension methods for mapping A2A protocol endpoints for AI agents.
+/// </summary>
+[Experimental(DiagnosticIds.Experiments.AIResponseContinuations)]
+public static class A2AEndpointRouteBuilderExtensions
+{
+    /// <summary>
+    /// Maps A2A HTTP+JSON endpoints for the specified agent to the given path.
+    /// An <see cref="A2AServer"/> for the agent must be registered first by calling
+    /// <c>AddA2AServer</c> during service registration.
+    /// </summary>
+    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
+    /// <param name="agentBuilder">The configuration builder for the agent.</param>
+    /// <param name="path">The route path prefix for A2A endpoints.</param>
+    /// <returns>An <see cref="IEndpointConventionBuilder"/> for further endpoint configuration.</returns>
+    public static IEndpointConventionBuilder MapA2AHttpJson(this IEndpointRouteBuilder endpoints, IHostedAgentBuilder agentBuilder, string path)
+    {
+        ArgumentNullException.ThrowIfNull(agentBuilder);
+
+        return endpoints.MapA2AHttpJson(agentBuilder.Name, path);
+    }
+
+    /// <summary>
+    /// Maps A2A HTTP+JSON endpoints for the specified agent to the given path.
+    /// An <see cref="A2AServer"/> for the agent must be registered first by calling
+    /// <c>AddA2AServer</c> during service registration.
+    /// </summary>
+    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
+    /// <param name="agent">The agent whose name identifies the registered A2A server.</param>
+    /// <param name="path">The route path prefix for A2A endpoints.</param>
+    /// <returns>An <see cref="IEndpointConventionBuilder"/> for further endpoint configuration.</returns>
+    public static IEndpointConventionBuilder MapA2AHttpJson(this IEndpointRouteBuilder endpoints, AIAgent agent, string path)
+    {
+        ArgumentNullException.ThrowIfNull(agent);
+        ArgumentException.ThrowIfNullOrWhiteSpace(agent.Name, nameof(agent) + "." + nameof(agent.Name));
+
+        return endpoints.MapA2AHttpJson(agent.Name, path);
+    }
+
+    /// <summary>
+    /// Maps A2A HTTP+JSON endpoints for the agent with the specified name to the given path.
+    /// An <see cref="A2AServer"/> for the agent must be registered first by calling
+    /// <c>AddA2AServer</c> during service registration.
+    /// </summary>
+    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
+    /// <param name="agentName">The name of the agent to use for A2A protocol integration.</param>
+    /// <param name="path">The route path prefix for A2A endpoints.</param>
+    /// <returns>An <see cref="IEndpointConventionBuilder"/> for further endpoint configuration.</returns>
+    public static IEndpointConventionBuilder MapA2AHttpJson(this IEndpointRouteBuilder endpoints, string agentName, string path)
+    {
+        ArgumentNullException.ThrowIfNull(endpoints);
+        ArgumentException.ThrowIfNullOrWhiteSpace(agentName);
+        ArgumentException.ThrowIfNullOrWhiteSpace(path);
+
+        var a2aServer = endpoints.ServiceProvider.GetKeyedService<A2AServer>(agentName)
+            ?? throw new InvalidOperationException(
+                $"No A2AServer is registered for agent '{agentName}'. " +
+                $"Call services.AddA2AServer(\"{agentName}\") or agentBuilder.AddA2AServer() during service registration to register one.");
+
+        // TODO: The stub AgentCard is temporary and will be removed once the A2A SDK either removes the
+        // agentCard parameter of MapHttpA2A or makes it optional. MapHttpA2A exposes the agent card via a
+        // GET {path}/card endpoint that is not part of the A2A spec, so it is not expected to be consumed
+        // by any agent - returning a stub agent card here is safe.
+        var stubAgentCard = new AgentCard { Name = "A2A Agent" };
+
+        return endpoints.MapHttpA2A(a2aServer, stubAgentCard, path);
+    }
+
+    /// <summary>
+    /// Maps A2A JSON-RPC endpoints for the specified agent to the given path.
+    /// An <see cref="A2AServer"/> for the agent must be registered first by calling
+    /// <c>AddA2AServer</c> during service registration.
+    /// </summary>
+    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
+    /// <param name="agentBuilder">The configuration builder for the agent.</param>
+    /// <param name="path">The route path prefix for A2A endpoints.</param>
+    /// <returns>An <see cref="IEndpointConventionBuilder"/> for further endpoint configuration.</returns>
+    public static IEndpointConventionBuilder MapA2AJsonRpc(this IEndpointRouteBuilder endpoints, IHostedAgentBuilder agentBuilder, string path)
+    {
+        ArgumentNullException.ThrowIfNull(agentBuilder);
+
+        return endpoints.MapA2AJsonRpc(agentBuilder.Name, path);
+    }
+
+    /// <summary>
+    /// Maps A2A JSON-RPC endpoints for the specified agent to the given path.
+    /// An <see cref="A2AServer"/> for the agent must be registered first by calling
+    /// <c>AddA2AServer</c> during service registration.
+    /// </summary>
+    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
+    /// <param name="agent">The agent whose name identifies the registered A2A server.</param>
+    /// <param name="path">The route path prefix for A2A endpoints.</param>
+    /// <returns>An <see cref="IEndpointConventionBuilder"/> for further endpoint configuration.</returns>
+    public static IEndpointConventionBuilder MapA2AJsonRpc(this IEndpointRouteBuilder endpoints, AIAgent agent, string path)
+    {
+        ArgumentNullException.ThrowIfNull(agent);
+        ArgumentException.ThrowIfNullOrWhiteSpace(agent.Name, nameof(agent) + "." + nameof(agent.Name));
+
+        return endpoints.MapA2AJsonRpc(agent.Name, path);
+    }
+
+    /// <summary>
+    /// Maps A2A JSON-RPC endpoints for the agent with the specified name to the given path.
+    /// An <see cref="A2AServer"/> for the agent must be registered first by calling
+    /// <c>AddA2AServer</c> during service registration.
+    /// </summary>
+    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
+    /// <param name="agentName">The name of the agent to use for A2A protocol integration.</param>
+    /// <param name="path">The route path prefix for A2A endpoints.</param>
+    /// <returns>An <see cref="IEndpointConventionBuilder"/> for further endpoint configuration.</returns>
+    public static IEndpointConventionBuilder MapA2AJsonRpc(this IEndpointRouteBuilder endpoints, string agentName, string path)
+    {
+        ArgumentNullException.ThrowIfNull(endpoints);
+        ArgumentException.ThrowIfNullOrWhiteSpace(agentName);
+        ArgumentException.ThrowIfNullOrWhiteSpace(path);
+
+        var a2aServer = endpoints.ServiceProvider.GetKeyedService<A2AServer>(agentName)
+            ?? throw new InvalidOperationException(
+                $"No A2AServer is registered for agent '{agentName}'. " +
+                $"Call services.AddA2AServer(\"{agentName}\") or agentBuilder.AddA2AServer() during service registration to register one.");
+
+        return endpoints.MapA2A(a2aServer, path);
+    }
+}

dotnet/src/Microsoft.Agents.AI.Hosting.A2A.AspNetCore/EndpointRouteBuilderExtensions.cs

@@ -1,385 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-
-using System;
-using System.Diagnostics.CodeAnalysis;
-using A2A;
-using A2A.AspNetCore;
-using Microsoft.Agents.AI;
-using Microsoft.Agents.AI.Hosting;
-using Microsoft.Agents.AI.Hosting.A2A;
-using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Routing;
-using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Logging;
-using Microsoft.Shared.DiagnosticIds;
-
-namespace Microsoft.AspNetCore.Builder;
-
-/// <summary>
-/// Provides extension methods for configuring A2A (Agent2Agent) communication in a host application builder.
-/// </summary>
-[Experimental(DiagnosticIds.Experiments.AIResponseContinuations)]
-public static class MicrosoftAgentAIHostingA2AEndpointRouteBuilderExtensions
-{
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agentBuilder">The configuration builder for <see cref="AIAgent"/>.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    /// <remarks>
-    /// This method can be used to access A2A agents that support the
-    /// <see href="https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md#2-curated-registries-catalog-based-discovery">Curated Registries (Catalog-Based Discovery)</see>
-    /// discovery mechanism.
-    /// </remarks>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, IHostedAgentBuilder agentBuilder, string path)
-        => endpoints.MapA2A(agentBuilder, path, _ => { });
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agentBuilder">The configuration builder for <see cref="AIAgent"/>.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentRunMode">Controls the response behavior of the agent run.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, IHostedAgentBuilder agentBuilder, string path, AgentRunMode agentRunMode)
-    {
-        ArgumentNullException.ThrowIfNull(agentBuilder);
-        return endpoints.MapA2A(agentBuilder.Name, path, agentRunMode);
-    }
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agentName">The name of the agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, string agentName, string path)
-        => endpoints.MapA2A(agentName, path, _ => { });
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agentName">The name of the agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentRunMode">Controls the response behavior of the agent run.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, string agentName, string path, AgentRunMode agentRunMode)
-    {
-        ArgumentNullException.ThrowIfNull(endpoints);
-        var agent = endpoints.ServiceProvider.GetRequiredKeyedService<AIAgent>(agentName);
-        return endpoints.MapA2A(agent, path, _ => { }, agentRunMode);
-    }
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agentBuilder">The configuration builder for <see cref="AIAgent"/>.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="configureTaskManager">The callback to configure <see cref="ITaskManager"/>.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    /// <remarks>
-    /// This method can be used to access A2A agents that support the
-    /// <see href="https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md#2-curated-registries-catalog-based-discovery">Curated Registries (Catalog-Based Discovery)</see>
-    /// discovery mechanism.
-    /// </remarks>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, IHostedAgentBuilder agentBuilder, string path, Action<ITaskManager> configureTaskManager)
-    {
-        ArgumentNullException.ThrowIfNull(agentBuilder);
-        return endpoints.MapA2A(agentBuilder.Name, path, configureTaskManager);
-    }
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agentName">The name of the agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="configureTaskManager">The callback to configure <see cref="ITaskManager"/>.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, string agentName, string path, Action<ITaskManager> configureTaskManager)
-    {
-        ArgumentNullException.ThrowIfNull(endpoints);
-        var agent = endpoints.ServiceProvider.GetRequiredKeyedService<AIAgent>(agentName);
-        return endpoints.MapA2A(agent, path, configureTaskManager);
-    }
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agentBuilder">The configuration builder for <see cref="AIAgent"/>.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentCard">Agent card info to return on query.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    /// <remarks>
-    /// This method can be used to access A2A agents that support the
-    /// <see href="https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md#2-curated-registries-catalog-based-discovery">Curated Registries (Catalog-Based Discovery)</see>
-    /// discovery mechanism.
-    /// </remarks>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, IHostedAgentBuilder agentBuilder, string path, AgentCard agentCard)
-        => endpoints.MapA2A(agentBuilder, path, agentCard, _ => { });
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agentName">The name of the agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentCard">Agent card info to return on query.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    /// <remarks>
-    /// This method can be used to access A2A agents that support the
-    /// <see href="https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md#2-curated-registries-catalog-based-discovery">Curated Registries (Catalog-Based Discovery)</see>
-    /// discovery mechanism.
-    /// </remarks>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, string agentName, string path, AgentCard agentCard)
-        => endpoints.MapA2A(agentName, path, agentCard, _ => { });
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agentBuilder">The configuration builder for <see cref="AIAgent"/>.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentCard">Agent card info to return on query.</param>
-    /// <param name="agentRunMode">Controls the response behavior of the agent run.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, IHostedAgentBuilder agentBuilder, string path, AgentCard agentCard, AgentRunMode agentRunMode)
-    {
-        ArgumentNullException.ThrowIfNull(agentBuilder);
-        return endpoints.MapA2A(agentBuilder.Name, path, agentCard, agentRunMode);
-    }
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agentName">The name of the agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentCard">Agent card info to return on query.</param>
-    /// <param name="agentRunMode">Controls the response behavior of the agent run.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, string agentName, string path, AgentCard agentCard, AgentRunMode agentRunMode)
-    {
-        ArgumentNullException.ThrowIfNull(endpoints);
-        var agent = endpoints.ServiceProvider.GetRequiredKeyedService<AIAgent>(agentName);
-        return endpoints.MapA2A(agent, path, agentCard, agentRunMode);
-    }
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agentBuilder">The configuration builder for <see cref="AIAgent"/>.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentCard">Agent card info to return on query.</param>
-    /// <param name="configureTaskManager">The callback to configure <see cref="ITaskManager"/>.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    /// <remarks>
-    /// This method can be used to access A2A agents that support the
-    /// <see href="https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md#2-curated-registries-catalog-based-discovery">Curated Registries (Catalog-Based Discovery)</see>
-    /// discovery mechanism.
-    /// </remarks>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, IHostedAgentBuilder agentBuilder, string path, AgentCard agentCard, Action<ITaskManager> configureTaskManager)
-    {
-        ArgumentNullException.ThrowIfNull(agentBuilder);
-        return endpoints.MapA2A(agentBuilder.Name, path, agentCard, configureTaskManager);
-    }
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agentName">The name of the agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentCard">Agent card info to return on query.</param>
-    /// <param name="configureTaskManager">The callback to configure <see cref="ITaskManager"/>.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    /// <remarks>
-    /// This method can be used to access A2A agents that support the
-    /// <see href="https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md#2-curated-registries-catalog-based-discovery">Curated Registries (Catalog-Based Discovery)</see>
-    /// discovery mechanism.
-    /// </remarks>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, string agentName, string path, AgentCard agentCard, Action<ITaskManager> configureTaskManager)
-        => endpoints.MapA2A(agentName, path, agentCard, configureTaskManager, AgentRunMode.DisallowBackground);
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agentName">The name of the agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentCard">Agent card info to return on query.</param>
-    /// <param name="configureTaskManager">The callback to configure <see cref="ITaskManager"/>.</param>
-    /// <param name="agentRunMode">Controls the response behavior of the agent run.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    /// <remarks>
-    /// This method can be used to access A2A agents that support the
-    /// <see href="https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md#2-curated-registries-catalog-based-discovery">Curated Registries (Catalog-Based Discovery)</see>
-    /// discovery mechanism.
-    /// </remarks>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, string agentName, string path, AgentCard agentCard, Action<ITaskManager> configureTaskManager, AgentRunMode agentRunMode)
-    {
-        ArgumentNullException.ThrowIfNull(endpoints);
-        var agent = endpoints.ServiceProvider.GetRequiredKeyedService<AIAgent>(agentName);
-        return endpoints.MapA2A(agent, path, agentCard, configureTaskManager, agentRunMode);
-    }
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agent">The agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, AIAgent agent, string path)
-        => endpoints.MapA2A(agent, path, _ => { });
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agent">The agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentRunMode">Controls the response behavior of the agent run.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, AIAgent agent, string path, AgentRunMode agentRunMode)
-        => endpoints.MapA2A(agent, path, _ => { }, agentRunMode);
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agent">The agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="configureTaskManager">The callback to configure <see cref="ITaskManager"/>.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, AIAgent agent, string path, Action<ITaskManager> configureTaskManager)
-        => endpoints.MapA2A(agent, path, configureTaskManager, AgentRunMode.DisallowBackground);
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agent">The agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="configureTaskManager">The callback to configure <see cref="ITaskManager"/>.</param>
-    /// <param name="agentRunMode">Controls the response behavior of the agent run.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, AIAgent agent, string path, Action<ITaskManager> configureTaskManager, AgentRunMode agentRunMode)
-    {
-        ArgumentNullException.ThrowIfNull(endpoints);
-        ArgumentNullException.ThrowIfNull(agent);
-
-        var loggerFactory = endpoints.ServiceProvider.GetRequiredService<ILoggerFactory>();
-        var agentSessionStore = endpoints.ServiceProvider.GetKeyedService<AgentSessionStore>(agent.Name);
-        var taskManager = agent.MapA2A(loggerFactory: loggerFactory, agentSessionStore: agentSessionStore, runMode: agentRunMode);
-        var endpointConventionBuilder = endpoints.MapA2A(taskManager, path);
-
-        configureTaskManager(taskManager);
-        return endpointConventionBuilder;
-    }
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agent">The agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentCard">Agent card info to return on query.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    /// <remarks>
-    /// This method can be used to access A2A agents that support the
-    /// <see href="https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md#2-curated-registries-catalog-based-discovery">Curated Registries (Catalog-Based Discovery)</see>
-    /// discovery mechanism.
-    /// </remarks>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, AIAgent agent, string path, AgentCard agentCard)
-        => endpoints.MapA2A(agent, path, agentCard, _ => { });
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agent">The agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentCard">Agent card info to return on query.</param>
-    /// <param name="agentRunMode">Controls the response behavior of the agent run.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    /// <remarks>
-    /// This method can be used to access A2A agents that support the
-    /// <see href="https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md#2-curated-registries-catalog-based-discovery">Curated Registries (Catalog-Based Discovery)</see>
-    /// discovery mechanism.
-    /// </remarks>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, AIAgent agent, string path, AgentCard agentCard, AgentRunMode agentRunMode)
-        => endpoints.MapA2A(agent, path, agentCard, _ => { }, agentRunMode);
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agent">The agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentCard">Agent card info to return on query.</param>
-    /// <param name="configureTaskManager">The callback to configure <see cref="ITaskManager"/>.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    /// <remarks>
-    /// This method can be used to access A2A agents that support the
-    /// <see href="https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md#2-curated-registries-catalog-based-discovery">Curated Registries (Catalog-Based Discovery)</see>
-    /// discovery mechanism.
-    /// </remarks>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, AIAgent agent, string path, AgentCard agentCard, Action<ITaskManager> configureTaskManager)
-        => endpoints.MapA2A(agent, path, agentCard, configureTaskManager, AgentRunMode.DisallowBackground);
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) communication capabilities via Message processing to the specified web application.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="agent">The agent to use for A2A protocol integration.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <param name="agentCard">Agent card info to return on query.</param>
-    /// <param name="configureTaskManager">The callback to configure <see cref="ITaskManager"/>.</param>
-    /// <param name="agentRunMode">Controls the response behavior of the agent run.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    /// <remarks>
-    /// This method can be used to access A2A agents that support the
-    /// <see href="https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md#2-curated-registries-catalog-based-discovery">Curated Registries (Catalog-Based Discovery)</see>
-    /// discovery mechanism.
-    /// </remarks>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, AIAgent agent, string path, AgentCard agentCard, Action<ITaskManager> configureTaskManager, AgentRunMode agentRunMode)
-    {
-        ArgumentNullException.ThrowIfNull(endpoints);
-        ArgumentNullException.ThrowIfNull(agent);
-
-        var loggerFactory = endpoints.ServiceProvider.GetRequiredService<ILoggerFactory>();
-        var agentSessionStore = endpoints.ServiceProvider.GetKeyedService<AgentSessionStore>(agent.Name);
-        var taskManager = agent.MapA2A(agentCard: agentCard, agentSessionStore: agentSessionStore, loggerFactory: loggerFactory, runMode: agentRunMode);
-        var endpointConventionBuilder = endpoints.MapA2A(taskManager, path);
-
-        configureTaskManager(taskManager);
-
-        return endpointConventionBuilder;
-    }
-
-    /// <summary>
-    /// Maps HTTP A2A communication endpoints to the specified path using the provided TaskManager.
-    /// TaskManager should be preconfigured before calling this method.
-    /// </summary>
-    /// <param name="endpoints">The <see cref="IEndpointRouteBuilder"/> to add the A2A endpoints to.</param>
-    /// <param name="taskManager">Pre-configured A2A TaskManager to use for A2A endpoints handling.</param>
-    /// <param name="path">The route group to use for A2A endpoints.</param>
-    /// <returns>Configured <see cref="ITaskManager"/> for A2A integration.</returns>
-    public static IEndpointConventionBuilder MapA2A(this IEndpointRouteBuilder endpoints, ITaskManager taskManager, string path)
-    {
-        // note: current SDK version registers multiple `.well-known/agent.json` handlers here.
-        // it makes app return HTTP 500, but will be fixed once new A2A SDK is released.
-        // see https://github.com/microsoft/agent-framework/issues/476 for details
-        A2ARouteBuilderExtensions.MapA2A(endpoints, taskManager, path);
-        return endpoints.MapHttpA2A(taskManager, path);
-    }
-}

dotnet/src/Microsoft.Agents.AI.Hosting.A2A.AspNetCore/Microsoft.Agents.AI.Hosting.A2A.AspNetCore.csproj

@@ -1,9 +1,12 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFrameworks>$(TargetFrameworksCore)</TargetFrameworks>
     <RootNamespace>Microsoft.Agents.AI.Hosting.A2A.AspNetCore</RootNamespace>
     <VersionSuffix>preview</VersionSuffix>
+    <!-- RT0002: Microsoft.Agents.AI.Hosting.A2A is intentionally referenced as a transitive dependency
+         so that consumers of this package automatically get the AddA2AServer registration extensions. -->
+    <NoWarn>$(NoWarn);RT0002</NoWarn>
   </PropertyGroup>
 
   <Import Project="$(RepoRoot)/dotnet/nuget/nuget-package.props" />
@@ -13,7 +16,7 @@
     <InjectSharedDiagnosticIds>true</InjectSharedDiagnosticIds>
     <InjectExperimentalAttributeOnLegacy>true</InjectExperimentalAttributeOnLegacy>
   </PropertyGroup>
-  
+
   <ItemGroup>
     <PackageReference Include="A2A.AspNetCore" />
   </ItemGroup>
@@ -21,7 +24,7 @@
   <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible($(TargetFramework), 'net10.0'))">
     <PackageReference Include="System.Linq.AsyncEnumerable" />
   </ItemGroup>
-  
+
   <ItemGroup>
     <ProjectReference Include="..\Microsoft.Agents.AI.Hosting.A2A\Microsoft.Agents.AI.Hosting.A2A.csproj" />
   </ItemGroup>

dotnet/src/Microsoft.Agents.AI.Hosting.A2A/A2AAgentHandler.cs

@@ -0,0 +1,192 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Threading;
+using System.Threading.Tasks;
+using A2A;
+using Microsoft.Agents.AI.Hosting.A2A.Converters;
+using Microsoft.Extensions.AI;
+using Microsoft.Shared.DiagnosticIds;
+
+namespace Microsoft.Agents.AI.Hosting.A2A;
+
+/// <summary>
+/// An <see cref="IAgentHandler"/> implementation that bridges an <see cref="AIAgent"/> to the
+/// A2A (Agent2Agent) protocol. Handles message execution and cancellation by delegating to
+/// the underlying agent and translating responses into A2A events.
+/// </summary>
+[Experimental(DiagnosticIds.Experiments.AIResponseContinuations)]
+internal sealed class A2AAgentHandler : IAgentHandler
+{
+    private readonly AIHostAgent _hostAgent;
+    private readonly AgentRunMode _runMode;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="A2AAgentHandler"/> class.
+    /// </summary>
+    /// <param name="hostAgent">The hosted agent that provides the execution logic.</param>
+    /// <param name="runMode">Controls whether the agent runs in background mode.</param>
+    public A2AAgentHandler(
+        AIHostAgent hostAgent,
+        AgentRunMode runMode)
+    {
+        ArgumentNullException.ThrowIfNull(hostAgent);
+        ArgumentNullException.ThrowIfNull(runMode);
+
+        this._hostAgent = hostAgent;
+        this._runMode = runMode;
+    }
+
+    /// <inheritdoc/>
+    public Task ExecuteAsync(RequestContext context, AgentEventQueue eventQueue, CancellationToken cancellationToken)
+    {
+        if (context.IsContinuation)
+        {
+            return this.HandleTaskUpdateAsync(context, eventQueue, cancellationToken);
+        }
+
+        return this.HandleNewMessageAsync(context, eventQueue, cancellationToken);
+    }
+
+    /// <inheritdoc/>
+    public async Task CancelAsync(RequestContext context, AgentEventQueue eventQueue, CancellationToken cancellationToken)
+    {
+        var taskUpdater = new TaskUpdater(eventQueue, context.TaskId, context.ContextId);
+        await taskUpdater.CancelAsync(cancellationToken).ConfigureAwait(false);
+    }
+
+    private async Task HandleNewMessageAsync(RequestContext context, AgentEventQueue eventQueue, CancellationToken cancellationToken)
+    {
+        var contextId = context.ContextId ?? Guid.NewGuid().ToString("N");
+        var session = await this._hostAgent.GetOrCreateSessionAsync(contextId, cancellationToken).ConfigureAwait(false);
+
+        // AIAgent does not support resuming from arbitrary prior tasks.
+        // Throw explicitly so the client gets a clear error rather than a response
+        // that silently ignores the referenced task context.
+        if (context.Message?.ReferenceTaskIds is { Count: > 0 })
+        {
+            throw new NotSupportedException("ReferenceTaskIds is not supported. AIAgent cannot resume from arbitrary prior task context.");
+        }
+
+        List<ChatMessage> chatMessages = context.Message is not null ? [context.Message.ToChatMessage()] : [];
+
+        // Decide whether to run in background based on user preferences and agent capabilities
+        var decisionContext = new A2ARunDecisionContext(context);
+        var allowBackgroundResponses = await this._runMode.ShouldRunInBackgroundAsync(decisionContext, cancellationToken).ConfigureAwait(false);
+
+        var options = context.Metadata is not { Count: > 0 }
+            ? new AgentRunOptions { AllowBackgroundResponses = allowBackgroundResponses }
+            : new AgentRunOptions { AllowBackgroundResponses = allowBackgroundResponses, AdditionalProperties = context.Metadata.ToAdditionalProperties() };
+
+        var response = await this._hostAgent.RunAsync(
+            chatMessages,
+            session: session,
+            options: options,
+            cancellationToken: cancellationToken).ConfigureAwait(false);
+
+        await this._hostAgent.SaveSessionAsync(contextId, session, cancellationToken).ConfigureAwait(false);
+
+        if (response.ContinuationToken is null)
+        {
+            // Return a lightweight message response (no task lifecycle needed).
+            var message = CreateMessageFromResponse(contextId, response);
+            await eventQueue.EnqueueMessageAsync(message, cancellationToken).ConfigureAwait(false);
+        }
+        else
+        {
+            // Long-running operation: emit task lifecycle events.
+            var taskUpdater = new TaskUpdater(eventQueue, context.TaskId, contextId);
+            await taskUpdater.SubmitAsync(cancellationToken).ConfigureAwait(false);
+
+            Message? progressMessage = response.Messages.Count > 0
+                ? CreateMessageFromResponse(contextId, response)
+                : null;
+
+            await taskUpdater.StartWorkAsync(progressMessage, cancellationToken).ConfigureAwait(false);
+        }
+    }
+
+    private async Task HandleTaskUpdateAsync(RequestContext context, AgentEventQueue eventQueue, CancellationToken cancellationToken)
+    {
+        var contextId = context.ContextId ?? Guid.NewGuid().ToString("N");
+        var session = await this._hostAgent.GetOrCreateSessionAsync(contextId, cancellationToken).ConfigureAwait(false);
+
+        List<ChatMessage> chatMessages = ExtractChatMessagesFromTaskHistory(context.Task);
+
+        var decisionContext = new A2ARunDecisionContext(context);
+        var allowBackgroundResponses = await this._runMode.ShouldRunInBackgroundAsync(decisionContext, cancellationToken).ConfigureAwait(false);
+
+        var options = context.Metadata is not { Count: > 0 }
+            ? new AgentRunOptions { AllowBackgroundResponses = allowBackgroundResponses }
+            : new AgentRunOptions { AllowBackgroundResponses = allowBackgroundResponses, AdditionalProperties = context.Metadata.ToAdditionalProperties() };
+
+        AgentResponse response;
+        try
+        {
+            response = await this._hostAgent.RunAsync(
+                chatMessages,
+                session: session,
+                options: options,
+                cancellationToken: cancellationToken).ConfigureAwait(false);
+        }
+        catch (OperationCanceledException)
+        {
+            throw;
+        }
+        catch (Exception)
+        {
+            var failUpdater = new TaskUpdater(eventQueue, context.TaskId, contextId);
+            await failUpdater.FailAsync(message: null, CancellationToken.None).ConfigureAwait(false);
+            throw;
+        }
+
+        await this._hostAgent.SaveSessionAsync(contextId, session, cancellationToken).ConfigureAwait(false);
+
+        if (response.ContinuationToken is null)
+        {
+            // Complete the task with an artifact containing the response.
+            var taskUpdater = new TaskUpdater(eventQueue, context.TaskId, contextId);
+            await taskUpdater.AddArtifactAsync(response.Messages.ToParts(), cancellationToken: cancellationToken).ConfigureAwait(false);
+            await taskUpdater.CompleteAsync(message: null, cancellationToken).ConfigureAwait(false);
+        }
+        else
+        {
+            // Still working: emit progress status.
+            var taskUpdater = new TaskUpdater(eventQueue, context.TaskId, contextId);
+
+            Message? progressMessage = response.Messages.Count > 0
+                ? CreateMessageFromResponse(contextId, response)
+                : null;
+
+            await taskUpdater.StartWorkAsync(progressMessage, cancellationToken).ConfigureAwait(false);
+        }
+    }
+
+    private static Message CreateMessageFromResponse(string contextId, AgentResponse response) =>
+        new()
+        {
+            MessageId = response.ResponseId ?? Guid.NewGuid().ToString("N"),
+            ContextId = contextId,
+            Role = Role.Agent,
+            Parts = response.Messages.ToParts(),
+            Metadata = response.AdditionalProperties?.ToA2AMetadata()
+        };
+
+    private static List<ChatMessage> ExtractChatMessagesFromTaskHistory(AgentTask? agentTask)
+    {
+        if (agentTask?.History is not { Count: > 0 })
+        {
+            return [];
+        }
+
+        var chatMessages = new List<ChatMessage>(agentTask.History.Count);
+        foreach (var message in agentTask.History)
+        {
+            chatMessages.Add(message.ToChatMessage());
+        }
+
+        return chatMessages;
+    }
+}

dotnet/src/Microsoft.Agents.AI.Hosting.A2A/A2ARunDecisionContext.cs

@@ -9,13 +9,13 @@ namespace Microsoft.Agents.AI.Hosting.A2A;
 /// </summary>
 public sealed class A2ARunDecisionContext
 {
-    internal A2ARunDecisionContext(MessageSendParams messageSendParams)
+    internal A2ARunDecisionContext(RequestContext requestContext)
     {
-        this.MessageSendParams = messageSendParams;
+        this.RequestContext = requestContext;
     }
 
     /// <summary>
-    /// Gets the parameters of the incoming A2A message that triggered this run.
+    /// Gets the request context of the incoming A2A request that triggered this run.
     /// </summary>
-    public MessageSendParams MessageSendParams { get; }
+    public RequestContext RequestContext { get; }
 }

dotnet/src/Microsoft.Agents.AI.Hosting.A2A/A2AServerRegistrationOptions.cs

@@ -0,0 +1,30 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Diagnostics.CodeAnalysis;
+using A2A;
+using Microsoft.Shared.DiagnosticIds;
+
+namespace Microsoft.Agents.AI.Hosting.A2A;
+
+/// <summary>
+/// Options for configuring A2A server registration.
+/// </summary>
+[Experimental(DiagnosticIds.Experiments.AIResponseContinuations)]
+public sealed class A2AServerRegistrationOptions
+{
+    /// <summary>
+    /// Gets or sets the agent run mode that controls how the agent responds to A2A requests.
+    /// </summary>
+    /// <remarks>
+    /// When <see langword="null"/>, defaults to <see cref="AgentRunMode.DisallowBackground"/>.
+    /// </remarks>
+    public AgentRunMode? AgentRunMode { get; set; }
+
+    /// <summary>
+    /// Gets or sets the A2A server options used to configure the underlying <see cref="A2AServer"/>.
+    /// </summary>
+    /// <remarks>
+    /// When <see langword="null"/>, no custom server options are applied.
+    /// </remarks>
+    public A2AServerOptions? ServerOptions { get; set; }
+}

dotnet/src/Microsoft.Agents.AI.Hosting.A2A/A2AServerServiceCollectionExtensions.cs

@@ -0,0 +1,160 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Diagnostics.CodeAnalysis;
+using A2A;
+using Microsoft.Agents.AI;
+using Microsoft.Agents.AI.Hosting;
+using Microsoft.Agents.AI.Hosting.A2A;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.Shared.DiagnosticIds;
+
+namespace Microsoft.Extensions.DependencyInjection;
+
+/// <summary>
+/// Provides extension methods for registering A2A server instances in the dependency injection container.
+/// </summary>
+[Experimental(DiagnosticIds.Experiments.AIResponseContinuations)]
+public static class A2AServerServiceCollectionExtensions
+{
+    /// <summary>
+    /// Registers an <see cref="A2AServer"/> in the dependency injection container, keyed by the agent name
+    /// specified in the <paramref name="agentBuilder"/>. This method only registers the server; to expose it
+    /// as an HTTP endpoint, call one of the <c>MapA2AHttpJson</c> or <c>MapA2AJsonRpc</c> endpoint mapping
+    /// methods during application startup.
+    /// </summary>
+    /// <param name="agentBuilder">The agent builder whose name identifies the agent.</param>
+    /// <param name="configureOptions">An optional callback to configure <see cref="A2AServerRegistrationOptions"/>.</param>
+    /// <returns>The <paramref name="agentBuilder"/> for chaining.</returns>
+    public static IHostedAgentBuilder AddA2AServer(this IHostedAgentBuilder agentBuilder, Action<A2AServerRegistrationOptions>? configureOptions = null)
+    {
+        ArgumentNullException.ThrowIfNull(agentBuilder);
+
+        agentBuilder.ServiceCollection.AddA2AServer(agentBuilder.Name, configureOptions);
+
+        return agentBuilder;
+    }
+
+    /// <summary>
+    /// Registers an <see cref="A2AServer"/> in the dependency injection container, keyed by the specified
+    /// agent name. This method only registers the server; to expose it as an HTTP endpoint, call one of the
+    /// <c>MapA2AHttpJson</c> or <c>MapA2AJsonRpc</c> endpoint mapping methods during application startup.
+    /// </summary>
+    /// <param name="builder">The host application builder to configure.</param>
+    /// <param name="agentName">The name of the agent to create an A2A server for.</param>
+    /// <param name="configureOptions">An optional callback to configure <see cref="A2AServerRegistrationOptions"/>.</param>
+    /// <returns>The <paramref name="builder"/> for chaining.</returns>
+    public static IHostApplicationBuilder AddA2AServer(this IHostApplicationBuilder builder, string agentName, Action<A2AServerRegistrationOptions>? configureOptions = null)
+    {
+        ArgumentNullException.ThrowIfNull(builder);
+
+        builder.Services.AddA2AServer(agentName, configureOptions);
+
+        return builder;
+    }
+
+    /// <summary>
+    /// Registers an <see cref="A2AServer"/> in the dependency injection container for the specified
+    /// <see cref="AIAgent"/> instance, keyed by the agent's <see cref="AIAgent.Name"/>. This method only
+    /// registers the server; to expose it as an HTTP endpoint, call one of the <c>MapA2AHttpJson</c> or
+    /// <c>MapA2AJsonRpc</c> endpoint mapping methods during application startup.
+    /// </summary>
+    /// <param name="builder">The host application builder to configure.</param>
+    /// <param name="agent">The agent instance to create an A2A server for.</param>
+    /// <param name="configureOptions">An optional callback to configure <see cref="A2AServerRegistrationOptions"/>.</param>
+    /// <returns>The <paramref name="builder"/> for chaining.</returns>
+    public static IHostApplicationBuilder AddA2AServer(this IHostApplicationBuilder builder, AIAgent agent, Action<A2AServerRegistrationOptions>? configureOptions = null)
+    {
+        ArgumentNullException.ThrowIfNull(builder);
+
+        builder.Services.AddA2AServer(agent, configureOptions);
+
+        return builder;
+    }
+
+    /// <summary>
+    /// Registers an <see cref="A2AServer"/> in the dependency injection container, keyed by the specified
+    /// agent name. This method only registers the server; to expose it as an HTTP endpoint, call one of the
+    /// <c>MapA2AHttpJson</c> or <c>MapA2AJsonRpc</c> endpoint mapping methods during application startup.
+    /// </summary>
+    /// <param name="services">The service collection to add the A2A server to.</param>
+    /// <param name="agentName">The name of the agent to create an A2A server for.</param>
+    /// <param name="configureOptions">An optional callback to configure <see cref="A2AServerRegistrationOptions"/>.</param>
+    /// <returns>The <paramref name="services"/> for chaining.</returns>
+    public static IServiceCollection AddA2AServer(this IServiceCollection services, string agentName, Action<A2AServerRegistrationOptions>? configureOptions = null)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        ArgumentException.ThrowIfNullOrWhiteSpace(agentName);
+
+        A2AServerRegistrationOptions? options = null;
+        if (configureOptions is not null)
+        {
+            options = new A2AServerRegistrationOptions();
+            configureOptions(options);
+        }
+
+        services.AddKeyedSingleton(agentName, (sp, _) =>
+        {
+            var agent = sp.GetRequiredKeyedService<AIAgent>(agentName);
+            return CreateA2AServer(sp, agent, options);
+        });
+
+        return services;
+    }
+
+    /// <summary>
+    /// Registers an <see cref="A2AServer"/> in the dependency injection container for the specified
+    /// <see cref="AIAgent"/> instance, keyed by the agent's <see cref="AIAgent.Name"/>. This method only
+    /// registers the server; to expose it as an HTTP endpoint, call one of the <c>MapA2AHttpJson</c> or
+    /// <c>MapA2AJsonRpc</c> endpoint mapping methods during application startup.
+    /// </summary>
+    /// <param name="services">The service collection to add the A2A server to.</param>
+    /// <param name="agent">The agent instance to create an A2A server for.</param>
+    /// <param name="configureOptions">An optional callback to configure <see cref="A2AServerRegistrationOptions"/>.</param>
+    /// <returns>The <paramref name="services"/> for chaining.</returns>
+    public static IServiceCollection AddA2AServer(this IServiceCollection services, AIAgent agent, Action<A2AServerRegistrationOptions>? configureOptions = null)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        ArgumentNullException.ThrowIfNull(agent);
+        ArgumentException.ThrowIfNullOrWhiteSpace(agent.Name, nameof(agent) + "." + nameof(agent.Name));
+
+        A2AServerRegistrationOptions? options = null;
+        if (configureOptions is not null)
+        {
+            options = new A2AServerRegistrationOptions();
+            configureOptions(options);
+        }
+
+        services.AddKeyedSingleton(agent.Name, (sp, _) => CreateA2AServer(sp, agent, options));
+
+        return services;
+    }
+
+    private static A2AServer CreateA2AServer(IServiceProvider serviceProvider, AIAgent agent, A2AServerRegistrationOptions? options)
+    {
+        var agentHandler = serviceProvider.GetKeyedService<IAgentHandler>(agent.Name);
+        if (agentHandler is null)
+        {
+            var agentSessionStore = serviceProvider.GetKeyedService<AgentSessionStore>(agent.Name);
+            var runMode = options?.AgentRunMode ?? AgentRunMode.DisallowBackground;
+
+            var hostAgent = new AIHostAgent(
+                innerAgent: agent,
+                sessionStore: agentSessionStore ?? new InMemoryAgentSessionStore());
+
+            agentHandler = new A2AAgentHandler(hostAgent, runMode);
+        }
+
+        var loggerFactory = serviceProvider.GetService<ILoggerFactory>() ?? NullLoggerFactory.Instance;
+        var taskStore = serviceProvider.GetKeyedService<ITaskStore>(agent.Name) ?? new InMemoryTaskStore();
+
+        return new A2AServer(
+            agentHandler,
+            taskStore,
+            new ChannelEventNotifier(),
+            loggerFactory.CreateLogger<A2AServer>(),
+            options?.ServerOptions);
+    }
+}

dotnet/src/Microsoft.Agents.AI.Hosting.A2A/AIAgentExtensions.cs

@@ -1,309 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-
-using System;
-using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
-using System.Text.Json;
-using System.Threading;
-using System.Threading.Tasks;
-using A2A;
-using Microsoft.Agents.AI.Hosting.A2A.Converters;
-using Microsoft.Extensions.AI;
-using Microsoft.Extensions.Logging;
-using Microsoft.Shared.DiagnosticIds;
-
-namespace Microsoft.Agents.AI.Hosting.A2A;
-
-/// <summary>
-/// Provides extension methods for attaching A2A (Agent2Agent) messaging capabilities to an <see cref="AIAgent"/>.
-/// </summary>
-[Experimental(DiagnosticIds.Experiments.AIResponseContinuations)]
-public static class AIAgentExtensions
-{
-    // Metadata key used to store continuation tokens for long-running background operations
-    // in the AgentTask.Metadata dictionary, persisted by the task store.
-    private const string ContinuationTokenMetadataKey = "__a2a__continuationToken";
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) messaging capabilities via Message processing to the specified <see cref="AIAgent"/>.
-    /// </summary>
-    /// <param name="agent">Agent to attach A2A messaging processing capabilities to.</param>
-    /// <param name="taskManager">Instance of <see cref="TaskManager"/> to configure for A2A messaging. New instance will be created if not passed.</param>
-    /// <param name="loggerFactory">The logger factory to use for creating <see cref="ILogger"/> instances.</param>
-    /// <param name="agentSessionStore">The store to store session contents and metadata.</param>
-    /// <param name="runMode">Controls the response behavior of the agent run.</param>
-    /// <param name="jsonSerializerOptions">Optional <see cref="JsonSerializerOptions"/> for serializing and deserializing continuation tokens. Use this when the agent's continuation token contains custom types not registered in the default options. Falls back to <see cref="A2AHostingJsonUtilities.DefaultOptions"/> if not provided.</param>
-    /// <returns>The configured <see cref="TaskManager"/>.</returns>
-    public static ITaskManager MapA2A(
-        this AIAgent agent,
-        ITaskManager? taskManager = null,
-        ILoggerFactory? loggerFactory = null,
-        AgentSessionStore? agentSessionStore = null,
-        AgentRunMode? runMode = null,
-        JsonSerializerOptions? jsonSerializerOptions = null)
-    {
-        ArgumentNullException.ThrowIfNull(agent);
-        ArgumentNullException.ThrowIfNull(agent.Name);
-
-        runMode ??= AgentRunMode.DisallowBackground;
-
-        var hostAgent = new AIHostAgent(
-            innerAgent: agent,
-            sessionStore: agentSessionStore ?? new NoopAgentSessionStore());
-
-        taskManager ??= new TaskManager();
-
-        // Resolve the JSON serializer options for continuation token serialization. May be custom for the user's agent.
-        JsonSerializerOptions continuationTokenJsonOptions = jsonSerializerOptions ?? A2AHostingJsonUtilities.DefaultOptions;
-
-        // OnMessageReceived handles both message-only and task-based flows.
-        // The A2A SDK prioritizes OnMessageReceived over OnTaskCreated when both are set,
-        // so we consolidate all initial message handling here and return either
-        // an AgentMessage or AgentTask depending on the agent response.
-        // When the agent returns a ContinuationToken (long-running operation), a task is
-        // created for stateful tracking. Otherwise a lightweight AgentMessage is returned.
-        // See https://github.com/a2aproject/a2a-dotnet/issues/275
-        taskManager.OnMessageReceived += (p, ct) => OnMessageReceivedAsync(p, hostAgent, runMode, taskManager, continuationTokenJsonOptions, ct);
-
-        // Task flow for subsequent updates and cancellations
-        taskManager.OnTaskUpdated += (t, ct) => OnTaskUpdatedAsync(t, hostAgent, taskManager, continuationTokenJsonOptions, ct);
-        taskManager.OnTaskCancelled += OnTaskCancelledAsync;
-
-        return taskManager;
-    }
-
-    /// <summary>
-    /// Attaches A2A (Agent2Agent) messaging capabilities via Message processing to the specified <see cref="AIAgent"/>.
-    /// </summary>
-    /// <param name="agent">Agent to attach A2A messaging processing capabilities to.</param>
-    /// <param name="agentCard">The agent card to return on query.</param>
-    /// <param name="taskManager">Instance of <see cref="TaskManager"/> to configure for A2A messaging. New instance will be created if not passed.</param>
-    /// <param name="loggerFactory">The logger factory to use for creating <see cref="ILogger"/> instances.</param>
-    /// <param name="agentSessionStore">The store to store session contents and metadata.</param>
-    /// <param name="runMode">Controls the response behavior of the agent run.</param>
-    /// <param name="jsonSerializerOptions">Optional <see cref="JsonSerializerOptions"/> for serializing and deserializing continuation tokens. Use this when the agent's continuation token contains custom types not registered in the default options. Falls back to <see cref="A2AHostingJsonUtilities.DefaultOptions"/> if not provided.</param>
-    /// <returns>The configured <see cref="TaskManager"/>.</returns>
-    public static ITaskManager MapA2A(
-        this AIAgent agent,
-        AgentCard agentCard,
-        ITaskManager? taskManager = null,
-        ILoggerFactory? loggerFactory = null,
-        AgentSessionStore? agentSessionStore = null,
-        AgentRunMode? runMode = null,
-        JsonSerializerOptions? jsonSerializerOptions = null)
-    {
-        taskManager = agent.MapA2A(taskManager, loggerFactory, agentSessionStore, runMode, jsonSerializerOptions);
-
-        taskManager.OnAgentCardQuery += (context, query) =>
-        {
-            // A2A SDK assigns the url on its own
-            // we can help user if they did not set Url explicitly.
-            if (string.IsNullOrEmpty(agentCard.Url))
-            {
-                agentCard.Url = context.TrimEnd('/');
-            }
-
-            return Task.FromResult(agentCard);
-        };
-        return taskManager;
-    }
-
-    private static async Task<A2AResponse> OnMessageReceivedAsync(
-        MessageSendParams messageSendParams,
-        AIHostAgent hostAgent,
-        AgentRunMode runMode,
-        ITaskManager taskManager,
-        JsonSerializerOptions continuationTokenJsonOptions,
-        CancellationToken cancellationToken)
-    {
-        // AIAgent does not support resuming from arbitrary prior tasks.
-        // Throw explicitly so the client gets a clear error rather than a response
-        // that silently ignores the referenced task context.
-        // Follow-ups on the *same* task are handled via OnTaskUpdated instead.
-        if (messageSendParams.Message.ReferenceTaskIds is { Count: > 0 })
-        {
-            throw new NotSupportedException("ReferenceTaskIds is not supported. AIAgent cannot resume from arbitrary prior task context. Use OnTaskUpdated for follow-ups on the same task.");
-        }
-
-        var contextId = messageSendParams.Message.ContextId ?? Guid.NewGuid().ToString("N");
-        var session = await hostAgent.GetOrCreateSessionAsync(contextId, cancellationToken).ConfigureAwait(false);
-
-        // Decide whether to run in background based on user preferences and agent capabilities
-        var decisionContext = new A2ARunDecisionContext(messageSendParams);
-        var allowBackgroundResponses = await runMode.ShouldRunInBackgroundAsync(decisionContext, cancellationToken).ConfigureAwait(false);
-
-        var options = messageSendParams.Metadata is not { Count: > 0 }
-            ? new AgentRunOptions { AllowBackgroundResponses = allowBackgroundResponses }
-            : new AgentRunOptions { AllowBackgroundResponses = allowBackgroundResponses, AdditionalProperties = messageSendParams.Metadata.ToAdditionalProperties() };
-
-        var response = await hostAgent.RunAsync(
-            messageSendParams.ToChatMessages(),
-            session: session,
-            options: options,
-            cancellationToken: cancellationToken).ConfigureAwait(false);
-
-        await hostAgent.SaveSessionAsync(contextId, session, cancellationToken).ConfigureAwait(false);
-
-        if (response.ContinuationToken is null)
-        {
-            return CreateMessageFromResponse(contextId, response);
-        }
-
-        var agentTask = await InitializeTaskAsync(contextId, messageSendParams.Message, taskManager, cancellationToken).ConfigureAwait(false);
-        StoreContinuationToken(agentTask, response.ContinuationToken, continuationTokenJsonOptions);
-        await TransitionToWorkingAsync(agentTask.Id, contextId, response, taskManager, cancellationToken).ConfigureAwait(false);
-        return agentTask;
-    }
-
-    private static async Task OnTaskUpdatedAsync(
-        AgentTask agentTask,
-        AIHostAgent hostAgent,
-        ITaskManager taskManager,
-        JsonSerializerOptions continuationTokenJsonOptions,
-        CancellationToken cancellationToken)
-    {
-        var contextId = agentTask.ContextId ?? Guid.NewGuid().ToString("N");
-        var session = await hostAgent.GetOrCreateSessionAsync(contextId, cancellationToken).ConfigureAwait(false);
-
-        try
-        {
-            // Discard any stale continuation token — the incoming user message supersedes
-            // any previous background operation. AF agents don't support updating existing 
-            // background responses (long-running operations); we start a fresh run from the
-            // existing session using the full chat history (which includes the new message).
-            agentTask.Metadata?.Remove(ContinuationTokenMetadataKey);
-
-            await taskManager.UpdateStatusAsync(agentTask.Id, TaskState.Working, cancellationToken: cancellationToken).ConfigureAwait(false);
-
-            var response = await hostAgent.RunAsync(
-                ExtractChatMessagesFromTaskHistory(agentTask),
-                session: session,
-                options: new AgentRunOptions { AllowBackgroundResponses = true },
-                cancellationToken: cancellationToken).ConfigureAwait(false);
-
-            await hostAgent.SaveSessionAsync(contextId, session, cancellationToken).ConfigureAwait(false);
-
-            if (response.ContinuationToken is not null)
-            {
-                StoreContinuationToken(agentTask, response.ContinuationToken, continuationTokenJsonOptions);
-                await TransitionToWorkingAsync(agentTask.Id, contextId, response, taskManager, cancellationToken).ConfigureAwait(false);
-            }
-            else
-            {
-                await CompleteWithArtifactAsync(agentTask.Id, response, taskManager, cancellationToken).ConfigureAwait(false);
-            }
-        }
-        catch (OperationCanceledException)
-        {
-            throw;
-        }
-        catch (Exception)
-        {
-            await taskManager.UpdateStatusAsync(
-                agentTask.Id,
-                TaskState.Failed,
-                final: true,
-                cancellationToken: cancellationToken).ConfigureAwait(false);
-            throw;
-        }
-    }
-
-    private static Task OnTaskCancelledAsync(AgentTask agentTask, CancellationToken cancellationToken)
-    {
-        // Remove the continuation token from metadata if present.
-        // The task has already been marked as cancelled by the TaskManager.
-        agentTask.Metadata?.Remove(ContinuationTokenMetadataKey);
-        return Task.CompletedTask;
-    }
-
-    private static AgentMessage CreateMessageFromResponse(string contextId, AgentResponse response) =>
-        new()
-        {
-            MessageId = response.ResponseId ?? Guid.NewGuid().ToString("N"),
-            ContextId = contextId,
-            Role = MessageRole.Agent,
-            Parts = response.Messages.ToParts(),
-            Metadata = response.AdditionalProperties?.ToA2AMetadata()
-        };
-
-    // Task outputs should be returned as artifacts rather than messages:
-    // https://a2a-protocol.org/latest/specification/#37-messages-and-artifacts
-    private static Artifact CreateArtifactFromResponse(AgentResponse response) =>
-        new()
-        {
-            ArtifactId = response.ResponseId ?? Guid.NewGuid().ToString("N"),
-            Parts = response.Messages.ToParts(),
-            Metadata = response.AdditionalProperties?.ToA2AMetadata()
-        };
-
-    private static async Task<AgentTask> InitializeTaskAsync(
-        string contextId,
-        AgentMessage originalMessage,
-        ITaskManager taskManager,
-        CancellationToken cancellationToken)
-    {
-        AgentTask agentTask = await taskManager.CreateTaskAsync(contextId, cancellationToken: cancellationToken).ConfigureAwait(false);
-
-        // Add the original user message to the task history.
-        // The A2A SDK does this internally when it creates tasks via OnTaskCreated.
-        agentTask.History ??= [];
-        agentTask.History.Add(originalMessage);
-
-        // Notify subscribers of the Submitted state per the A2A spec: https://a2a-protocol.org/latest/specification/#413-taskstate
-        await taskManager.UpdateStatusAsync(agentTask.Id, TaskState.Submitted, cancellationToken: cancellationToken).ConfigureAwait(false);
-
-        return agentTask;
-    }
-
-    private static void StoreContinuationToken(
-        AgentTask agentTask,
-        ResponseContinuationToken token,
-        JsonSerializerOptions continuationTokenJsonOptions)
-    {
-        // Serialize the continuation token into the task's metadata so it survives
-        // across requests and is cleaned up with the task itself.
-        agentTask.Metadata ??= [];
-        agentTask.Metadata[ContinuationTokenMetadataKey] = JsonSerializer.SerializeToElement(
-            token,
-            continuationTokenJsonOptions.GetTypeInfo(typeof(ResponseContinuationToken)));
-    }
-
-    private static async Task TransitionToWorkingAsync(
-        string taskId,
-        string contextId,
-        AgentResponse response,
-        ITaskManager taskManager,
-        CancellationToken cancellationToken)
-    {
-        // Include any intermediate progress messages from the response as a status message.
-        AgentMessage? progressMessage = response.Messages.Count > 0 ? CreateMessageFromResponse(contextId, response) : null;
-        await taskManager.UpdateStatusAsync(taskId, TaskState.Working, message: progressMessage, cancellationToken: cancellationToken).ConfigureAwait(false);
-    }
-
-    private static async Task CompleteWithArtifactAsync(
-        string taskId,
-        AgentResponse response,
-        ITaskManager taskManager,
-        CancellationToken cancellationToken)
-    {
-        var artifact = CreateArtifactFromResponse(response);
-        await taskManager.ReturnArtifactAsync(taskId, artifact, cancellationToken).ConfigureAwait(false);
-        await taskManager.UpdateStatusAsync(taskId, TaskState.Completed, final: true, cancellationToken: cancellationToken).ConfigureAwait(false);
-    }
-
-    private static List<ChatMessage> ExtractChatMessagesFromTaskHistory(AgentTask agentTask)
-    {
-        if (agentTask.History is not { Count: > 0 })
-        {
-            return [];
-        }
-
-        var chatMessages = new List<ChatMessage>(agentTask.History.Count);
-        foreach (var message in agentTask.History)
-        {
-            chatMessages.Add(message.ToChatMessage());
-        }
-
-        return chatMessages;
-    }
-}

dotnet/src/Microsoft.Agents.AI.Hosting.A2A/AgentRunMode.cs

@@ -2,6 +2,7 @@
 
 using System;
 using System.Diagnostics.CodeAnalysis;
+using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Shared.DiagnosticIds;
@@ -28,7 +29,7 @@ public sealed class AgentRunMode : IEquatable<AgentRunMode>
     }
 
     /// <summary>
-    /// Dissallows the background responses from the agent. Is equivalent to configuring <see cref="AgentRunOptions.AllowBackgroundResponses"/> as <c>false</c>.
+    /// Disallows the background responses from the agent. Is equivalent to configuring <see cref="AgentRunOptions.AllowBackgroundResponses"/> as <c>false</c>.
     /// In the A2A protocol terminology will make responses be returned as <c>AgentMessage</c>.
     /// </summary>
     public static AgentRunMode DisallowBackground => new(MessageValue);
@@ -79,18 +80,22 @@ public sealed class AgentRunMode : IEquatable<AgentRunMode>
         }
 
         // No delegate provided — fall back to "message" behavior.
-        return ValueTask.FromResult(true);
+        return ValueTask.FromResult(false);
     }
 
     /// <inheritdoc/>
     public bool Equals(AgentRunMode? other) =>
-        other is not null && string.Equals(this._value, other._value, StringComparison.OrdinalIgnoreCase);
+        other is not null
+        && string.Equals(this._value, other._value, StringComparison.OrdinalIgnoreCase)
+        && ReferenceEquals(this._runInBackground, other._runInBackground);
 
     /// <inheritdoc/>
     public override bool Equals(object? obj) => this.Equals(obj as AgentRunMode);
 
     /// <inheritdoc/>
-    public override int GetHashCode() => StringComparer.OrdinalIgnoreCase.GetHashCode(this._value);
+    public override int GetHashCode() => HashCode.Combine(
+        StringComparer.OrdinalIgnoreCase.GetHashCode(this._value),
+        RuntimeHelpers.GetHashCode(this._runInBackground));
 
     /// <inheritdoc/>
     public override string ToString() => this._value;

dotnet/src/Microsoft.Agents.AI.Hosting.A2A/Converters/MessageConverter.cs

@@ -31,21 +31,21 @@ internal static class MessageConverter
         return parts;
     }
     /// <summary>
-    /// Converts A2A MessageSendParams to a collection of Microsoft.Extensions.AI ChatMessage objects.
+    /// Converts A2A SendMessageRequest to a collection of Microsoft.Extensions.AI ChatMessage objects.
     /// </summary>
-    /// <param name="messageSendParams">The A2A message send parameters to convert.</param>
+    /// <param name="sendMessageRequest">The A2A send message request to convert.</param>
     /// <returns>A read-only collection of ChatMessage objects.</returns>
-    public static List<ChatMessage> ToChatMessages(this MessageSendParams messageSendParams)
+    public static List<ChatMessage> ToChatMessages(this SendMessageRequest sendMessageRequest)
     {
-        if (messageSendParams is null)
+        if (sendMessageRequest is null)
         {
             return [];
         }
 
         var result = new List<ChatMessage>();
-        if (messageSendParams.Message?.Parts is not null)
+        if (sendMessageRequest.Message?.Parts is not null)
         {
-            result.Add(messageSendParams.Message.ToChatMessage());
+            result.Add(sendMessageRequest.Message.ToChatMessage());
         }
 
         return result;

dotnet/tests/Microsoft.Agents.AI.A2A.UnitTests/A2AContinuationTokenTests.cs

@@ -106,6 +106,18 @@ public sealed class A2AContinuationTokenTests
         Assert.Throws<ArgumentException>(() => A2AContinuationToken.FromToken(emptyToken));
     }
 
+    [Fact]
+    public void FromToken_WithNullTaskIdValue_ThrowsJsonException()
+    {
+        // Arrange
+        var jsonWithNullTaskId = System.Text.Encoding.UTF8.GetBytes("{ \"taskId\": null }").AsMemory();
+        var mockToken = new MockResponseContinuationToken(jsonWithNullTaskId);
+
+        // Act & Assert
+        var ex = Assert.Throws<JsonException>(() => A2AContinuationToken.FromToken(mockToken));
+        Assert.Contains("taskId", ex.Message);
+    }
+
     [Fact]
     public void FromToken_WithMissingTaskIdProperty_ThrowsException()
     {

dotnet/tests/Microsoft.Agents.AI.A2A.UnitTests/Extensions/A2AAIContentExtensionsTests.cs

@@ -42,14 +42,14 @@ public sealed class A2AAIContentExtensionsTests
         Assert.NotNull(result);
         Assert.Equal(3, result.Count);
 
-        var firstTextPart = Assert.IsType<TextPart>(result[0]);
-        Assert.Equal("First text", firstTextPart.Text);
+        Assert.Equal(PartContentCase.Text, result[0].ContentCase);
+        Assert.Equal("First text", result[0].Text);
 
-        var filePart = Assert.IsType<FilePart>(result[1]);
-        Assert.Equal("https://example.com/file1.txt", filePart.File.Uri?.ToString());
+        Assert.Equal(PartContentCase.Url, result[1].ContentCase);
+        Assert.Equal("https://example.com/file1.txt", result[1].Url);
 
-        var secondTextPart = Assert.IsType<TextPart>(result[2]);
-        Assert.Equal("Second text", secondTextPart.Text);
+        Assert.Equal(PartContentCase.Text, result[2].ContentCase);
+        Assert.Equal("Second text", result[2].Text);
     }
 
     [Fact]
@@ -72,14 +72,14 @@ public sealed class A2AAIContentExtensionsTests
         Assert.NotNull(result);
         Assert.Equal(3, result.Count);
 
-        var firstTextPart = Assert.IsType<TextPart>(result[0]);
-        Assert.Equal("First text", firstTextPart.Text);
+        Assert.Equal(PartContentCase.Text, result[0].ContentCase);
+        Assert.Equal("First text", result[0].Text);
 
-        var filePart = Assert.IsType<FilePart>(result[1]);
-        Assert.Equal("https://example.com/file.txt", filePart.File.Uri?.ToString());
+        Assert.Equal(PartContentCase.Url, result[1].ContentCase);
+        Assert.Equal("https://example.com/file.txt", result[1].Url);
 
-        var secondTextPart = Assert.IsType<TextPart>(result[2]);
-        Assert.Equal("Second text", secondTextPart.Text);
+        Assert.Equal(PartContentCase.Text, result[2].ContentCase);
+        Assert.Equal("Second text", result[2].Text);
     }
 
     // Mock class for testing unsupported scenarios

dotnet/tests/Microsoft.Agents.AI.A2A.UnitTests/Extensions/A2AAgentCardExtensionsTests.cs

@@ -26,7 +26,7 @@ public sealed class A2AAgentCardExtensionsTests
         {
             Name = "Test Agent",
             Description = "A test agent for unit testing",
-            Url = "http://test-endpoint/agent"
+            SupportedInterfaces = [new AgentInterface { Url = "http://test-endpoint/agent" }]
         };
     }
 
@@ -50,13 +50,13 @@ public sealed class A2AAgentCardExtensionsTests
         using var handler = new HttpMessageHandlerStub();
         using var httpClient = new HttpClient(handler, false);
 
-        handler.ResponsesToReturn.Enqueue(new AgentMessage
+        handler.ResponsesToReturn.Enqueue(new Message
         {
-            Role = MessageRole.Agent,
-            Parts = [new TextPart { Text = "Response" }],
+            Role = Role.Agent,
+            Parts = [Part.FromText("Response")],
         });
 
-        var agent = this._agentCard.AsAIAgent(httpClient);
+        var agent = this._agentCard.AsAIAgent(httpClient: httpClient);
 
         // Act
         await agent.RunAsync("Test input");
@@ -66,6 +66,105 @@ public sealed class A2AAgentCardExtensionsTests
         Assert.Equal(new Uri("http://test-endpoint/agent"), handler.CapturedUris[0]);
     }
 
+    [Fact]
+    public async Task AsAIAgent_WithPreferredBindings_UsesMatchingInterfaceAsync()
+    {
+        // Arrange
+        var card = new AgentCard
+        {
+            Name = "Multi-Interface Agent",
+            Description = "An agent with multiple interfaces",
+            SupportedInterfaces =
+            [
+                new AgentInterface { Url = "http://first/agent", ProtocolBinding = ProtocolBindingNames.HttpJson },
+                new AgentInterface { Url = "http://second/agent", ProtocolBinding = ProtocolBindingNames.JsonRpc },
+            ]
+        };
+
+        using var handler = new HttpMessageHandlerStub();
+        using var httpClient = new HttpClient(handler, false);
+
+        handler.ResponsesToReturn.Enqueue(new Message
+        {
+            Role = Role.Agent,
+            Parts = [Part.FromText("Response")],
+        });
+
+        var options = new A2AClientOptions
+        {
+            PreferredBindings = [ProtocolBindingNames.JsonRpc]
+        };
+
+        var agent = card.AsAIAgent(httpClient, options: options);
+
+        // Act
+        await agent.RunAsync("Test input");
+
+        // Assert
+        Assert.Single(handler.CapturedUris);
+        Assert.Equal(new Uri("http://second/agent"), handler.CapturedUris[0]);
+    }
+
+    [Fact]
+    public void AsAIAgent_WithNullOptions_UsesDefaultBindingPreference()
+    {
+        // Arrange
+        var card = new AgentCard
+        {
+            Name = "Default Options Agent",
+            Description = "Tests default A2AClientOptions behavior",
+            SupportedInterfaces =
+            [
+                new AgentInterface { Url = "http://default/agent" },
+            ]
+        };
+
+        // Act - null options should use defaults (HTTP+JSON first, JSON-RPC as fallback)
+        var agent = card.AsAIAgent(options: null);
+
+        // Assert
+        Assert.NotNull(agent);
+        Assert.IsType<A2AAgent>(agent);
+        Assert.Equal("Default Options Agent", agent.Name);
+    }
+
+    [Fact]
+    public void AsAIAgent_WithNoMatchingBinding_ThrowsException()
+    {
+        // Arrange
+        var card = new AgentCard
+        {
+            Name = "Unmatched Binding Agent",
+            Description = "Agent with unsupported binding only",
+            SupportedInterfaces =
+            [
+                new AgentInterface { Url = "http://grpc/agent", ProtocolBinding = "GRPC" },
+            ]
+        };
+
+        var options = new A2AClientOptions
+        {
+            PreferredBindings = [ProtocolBindingNames.JsonRpc]
+        };
+
+        // Act & Assert - factory should throw when no matching binding exists
+        Assert.ThrowsAny<Exception>(() => card.AsAIAgent(options: options));
+    }
+
+    [Fact]
+    public void AsAIAgent_WithNoSupportedInterfaces_ThrowsException()
+    {
+        // Arrange
+        var card = new AgentCard
+        {
+            Name = "No Interfaces Agent",
+            Description = "Agent with no supported interfaces",
+        };
+
+        // Act & Assert
+        Assert.ThrowsAny<Exception>(() => card.AsAIAgent());
+    }
+
     internal sealed class HttpMessageHandlerStub : HttpMessageHandler
     {
         public Queue ResponsesToReturn { get; } = new();
@@ -86,13 +185,18 @@ public sealed class A2AAgentCardExtensionsTests
                     Content = new StringContent(json, Encoding.UTF8, "application/json")
                 };
             }
-            else if (response is AgentMessage message)
+            else if (response is Message message)
             {
-                var jsonRpcResponse = JsonRpcResponse.CreateJsonRpcResponse<A2AEvent>("response-id", message);
+                var sendMessageResponse = new SendMessageResponse { Message = message };
+                var jsonRpcResponse = new JsonRpcResponse
+                {
+                    Id = "response-id",
+                    Result = JsonSerializer.SerializeToNode(sendMessageResponse, A2AJsonUtilities.DefaultOptions)
+                };
 
                 return new HttpResponseMessage(HttpStatusCode.OK)
                 {
-                    Content = new StringContent(JsonSerializer.Serialize(jsonRpcResponse), Encoding.UTF8, "application/json")
+                    Content = new StringContent(JsonSerializer.Serialize(jsonRpcResponse, A2AJsonUtilities.DefaultOptions), Encoding.UTF8, "application/json")
                 };
             }
 

dotnet/tests/Microsoft.Agents.AI.A2A.UnitTests/Extensions/A2AAgentTaskExtensionsTests.cs

@@ -40,7 +40,7 @@ public sealed class A2AAgentTaskExtensionsTests
         {
             Id = "task1",
             Artifacts = [],
-            Status = new AgentTaskStatus { State = TaskState.Completed },
+            Status = new TaskStatus { State = TaskState.Completed },
         };
 
         // Act
@@ -58,7 +58,7 @@ public sealed class A2AAgentTaskExtensionsTests
         {
             Id = "task1",
             Artifacts = null,
-            Status = new AgentTaskStatus { State = TaskState.Completed },
+            Status = new TaskStatus { State = TaskState.Completed },
         };
 
         // Act
@@ -76,7 +76,7 @@ public sealed class A2AAgentTaskExtensionsTests
         {
             Id = "task1",
             Artifacts = [],
-            Status = new AgentTaskStatus { State = TaskState.Completed },
+            Status = new TaskStatus { State = TaskState.Completed },
         };
 
         // Act
@@ -94,7 +94,7 @@ public sealed class A2AAgentTaskExtensionsTests
         {
             Id = "task1",
             Artifacts = null,
-            Status = new AgentTaskStatus { State = TaskState.Completed },
+            Status = new TaskStatus { State = TaskState.Completed },
         };
 
         // Act
@@ -110,14 +110,14 @@ public sealed class A2AAgentTaskExtensionsTests
         // Arrange
         var artifact = new Artifact
         {
-            Parts = [new TextPart { Text = "response" }],
+            Parts = [Part.FromText("response")],
         };
 
         var agentTask = new AgentTask
         {
             Id = "task1",
             Artifacts = [artifact],
-            Status = new AgentTaskStatus { State = TaskState.Completed },
+            Status = new TaskStatus { State = TaskState.Completed },
         };
 
         // Act
@@ -136,15 +136,15 @@ public sealed class A2AAgentTaskExtensionsTests
         // Arrange
         var artifact1 = new Artifact
         {
-            Parts = [new TextPart { Text = "content1" }],
+            Parts = [Part.FromText("content1")],
         };
 
         var artifact2 = new Artifact
         {
             Parts =
             [
-                new TextPart { Text = "content2" },
-                new TextPart { Text = "content3" }
+                Part.FromText("content2"),
+                Part.FromText("content3")
             ],
         };
 
@@ -152,7 +152,7 @@ public sealed class A2AAgentTaskExtensionsTests
         {
             Id = "task1",
             Artifacts = [artifact1, artifact2],
-            Status = new AgentTaskStatus { State = TaskState.Completed },
+            Status = new TaskStatus { State = TaskState.Completed },
         };
 
         // Act

dotnet/tests/Microsoft.Agents.AI.A2A.UnitTests/Extensions/A2AArtifactExtensionsTests.cs

@@ -22,9 +22,9 @@ public sealed class A2AArtifactExtensionsTests
             Name = "comprehensive-artifact",
             Parts =
             [
-                new TextPart { Text = "First part" },
-                new TextPart { Text = "Second part" },
-                new TextPart { Text = "Third part" }
+                Part.FromText("First part"),
+                Part.FromText("Second part"),
+                Part.FromText("Third part")
             ],
             Metadata = new Dictionary<string, JsonElement>
             {
@@ -66,9 +66,9 @@ public sealed class A2AArtifactExtensionsTests
             Name = "test",
             Parts =
             [
-                new TextPart { Text = "Part 1" },
-                new TextPart { Text = "Part 2" },
-                new TextPart { Text = "Part 3" }
+                Part.FromText("Part 1"),
+                Part.FromText("Part 2"),
+                Part.FromText("Part 3")
             ],
             Metadata = null
         };

dotnet/tests/Microsoft.Agents.AI.A2A.UnitTests/Extensions/A2ACardResolverExtensionsTests.cs

@@ -37,7 +37,7 @@ public sealed class A2ACardResolverExtensionsTests : IDisposable
         {
             Name = "Test Agent",
             Description = "A test agent for unit testing",
-            Url = "http://test-endpoint/agent"
+            SupportedInterfaces = [new AgentInterface { Url = "http://test-endpoint/agent" }]
         });
 
         // Act
@@ -60,15 +60,15 @@ public sealed class A2ACardResolverExtensionsTests : IDisposable
         // Arrange
         this._handler.ResponsesToReturn.Enqueue(new AgentCard
         {
-            Url = "http://test-endpoint/agent"
+            SupportedInterfaces = [new AgentInterface { Url = "http://test-endpoint/agent" }]
         });
-        this._handler.ResponsesToReturn.Enqueue(new AgentMessage
+        this._handler.ResponsesToReturn.Enqueue(new Message
         {
-            Role = MessageRole.Agent,
-            Parts = [new TextPart { Text = "Response" }],
+            Role = Role.Agent,
+            Parts = [Part.FromText("Response")],
         });
 
-        var agent = await this._resolver.GetAIAgentAsync(this._httpClient);
+        var agent = await this._resolver.GetAIAgentAsync(httpClient: this._httpClient);
 
         // Act
         await agent.RunAsync("Test input");
@@ -78,6 +78,41 @@ public sealed class A2ACardResolverExtensionsTests : IDisposable
         Assert.Equal(new Uri("http://test-endpoint/agent"), this._handler.CapturedUris[1]);
     }
 
+    [Fact]
+    public async Task GetAIAgentAsync_WithOptions_PassesOptionsToFactoryAsync()
+    {
+        // Arrange
+        this._handler.ResponsesToReturn.Enqueue(new AgentCard
+        {
+            Name = "Options Agent",
+            Description = "Agent with multiple interfaces",
+            SupportedInterfaces =
+            [
+                new AgentInterface { Url = "http://httpjson/agent", ProtocolBinding = ProtocolBindingNames.HttpJson },
+                new AgentInterface { Url = "http://jsonrpc/agent", ProtocolBinding = ProtocolBindingNames.JsonRpc },
+            ]
+        });
+        this._handler.ResponsesToReturn.Enqueue(new Message
+        {
+            Role = Role.Agent,
+            Parts = [Part.FromText("Response")],
+        });
+
+        var options = new A2AClientOptions
+        {
+            PreferredBindings = [ProtocolBindingNames.JsonRpc]
+        };
+
+        var agent = await this._resolver.GetAIAgentAsync(httpClient: this._httpClient, options: options);
+
+        // Act
+        await agent.RunAsync("Test input");
+
+        // Assert
+        Assert.Equal(2, this._handler.CapturedUris.Count);
+        Assert.Equal(new Uri("http://jsonrpc/agent"), this._handler.CapturedUris[1]);
+    }
+
     public void Dispose()
     {
         this._handler.Dispose();
@@ -104,13 +139,18 @@ public sealed class A2ACardResolverExtensionsTests : IDisposable
                     Content = new StringContent(json, Encoding.UTF8, "application/json")
                 };
             }
-            else if (response is AgentMessage message)
+            else if (response is Message message)
             {
-                var jsonRpcResponse = JsonRpcResponse.CreateJsonRpcResponse<A2AEvent>("response-id", message);
+                var sendMessageResponse = new SendMessageResponse { Message = message };
+                var jsonRpcResponse = new JsonRpcResponse
+                {
+                    Id = "response-id",
+                    Result = JsonSerializer.SerializeToNode(sendMessageResponse, A2AJsonUtilities.DefaultOptions)
+                };
 
                 return new HttpResponseMessage(HttpStatusCode.OK)
                 {
-                    Content = new StringContent(JsonSerializer.Serialize(jsonRpcResponse), Encoding.UTF8, "application/json")
+                    Content = new StringContent(JsonSerializer.Serialize(jsonRpcResponse, A2AJsonUtilities.DefaultOptions), Encoding.UTF8, "application/json")
                 };
             }
 

dotnet/tests/Microsoft.Agents.AI.A2A.UnitTests/Extensions/A2AClientExtensionsTests.cs

@@ -30,4 +30,40 @@ public sealed class A2AClientExtensionsTests
         Assert.Equal(TestName, agent.Name);
         Assert.Equal(TestDescription, agent.Description);
     }
+
+    [Fact]
+    public void GetAIAgent_WithIA2AClient_ReturnsA2AAgentWithSpecifiedProperties()
+    {
+        // Arrange - use IA2AClient reference type to verify the extension method works with the interface
+        IA2AClient a2aClient = new A2AClient(new Uri("http://test-endpoint"));
+
+        const string TestId = "ia2a-agent-id";
+        const string TestName = "IA2A Agent";
+        const string TestDescription = "Agent created from IA2AClient";
+
+        // Act
+        var agent = a2aClient.AsAIAgent(TestId, TestName, TestDescription);
+
+        // Assert
+        Assert.NotNull(agent);
+        Assert.IsType<A2AAgent>(agent);
+        Assert.Equal(TestId, agent.Id);
+        Assert.Equal(TestName, agent.Name);
+        Assert.Equal(TestDescription, agent.Description);
+    }
+
+    [Fact]
+    public void GetAIAgent_WithIA2AClient_ExposesClientViaGetService()
+    {
+        // Arrange
+        IA2AClient a2aClient = new A2AClient(new Uri("http://test-endpoint"));
+
+        // Act
+        var agent = a2aClient.AsAIAgent();
+
+        // Assert
+        var service = agent.GetService(typeof(IA2AClient));
+        Assert.NotNull(service);
+        Assert.Same(a2aClient, service);
+    }
 }

dotnet/tests/Microsoft.Agents.AI.A2A.UnitTests/Extensions/ChatMessageExtensionsTests.cs

@@ -32,20 +32,19 @@ public sealed class ChatMessageExtensionsTests
         Assert.NotNull(a2aMessage.MessageId);
         Assert.NotEmpty(a2aMessage.MessageId);
 
-        Assert.Equal(MessageRole.User, a2aMessage.Role);
+        Assert.Equal(Role.User, a2aMessage.Role);
 
         Assert.NotNull(a2aMessage.Parts);
         Assert.Equal(3, a2aMessage.Parts.Count);
 
-        var filePart = Assert.IsType<FilePart>(a2aMessage.Parts[0]);
-        Assert.NotNull(filePart.File);
-        Assert.Equal("https://example.com/report.pdf", filePart.File.Uri?.ToString());
+        Assert.Equal(PartContentCase.Url, a2aMessage.Parts[0].ContentCase);
+        Assert.Equal("https://example.com/report.pdf", a2aMessage.Parts[0].Url);
 
-        var secondTextPart = Assert.IsType<TextPart>(a2aMessage.Parts[1]);
-        Assert.Equal("please summarize the file content", secondTextPart.Text);
+        Assert.Equal(PartContentCase.Text, a2aMessage.Parts[1].ContentCase);
+        Assert.Equal("please summarize the file content", a2aMessage.Parts[1].Text);
 
-        var thirdTextPart = Assert.IsType<TextPart>(a2aMessage.Parts[2]);
-        Assert.Equal("and send it to me over email", thirdTextPart.Text);
+        Assert.Equal(PartContentCase.Text, a2aMessage.Parts[2].ContentCase);
+        Assert.Equal("and send it to me over email", a2aMessage.Parts[2].Text);
     }
 
     [Fact]
@@ -71,19 +70,18 @@ public sealed class ChatMessageExtensionsTests
         Assert.NotNull(a2aMessage.MessageId);
         Assert.NotEmpty(a2aMessage.MessageId);
 
-        Assert.Equal(MessageRole.User, a2aMessage.Role);
+        Assert.Equal(Role.User, a2aMessage.Role);
 
         Assert.NotNull(a2aMessage.Parts);
         Assert.Equal(3, a2aMessage.Parts.Count);
 
-        var filePart = Assert.IsType<FilePart>(a2aMessage.Parts[0]);
-        Assert.NotNull(filePart.File);
-        Assert.Equal("https://example.com/report.pdf", filePart.File.Uri?.ToString());
+        Assert.Equal(PartContentCase.Url, a2aMessage.Parts[0].ContentCase);
+        Assert.Equal("https://example.com/report.pdf", a2aMessage.Parts[0].Url);
 
-        var secondTextPart = Assert.IsType<TextPart>(a2aMessage.Parts[1]);
-        Assert.Equal("please summarize the file content", secondTextPart.Text);
+        Assert.Equal(PartContentCase.Text, a2aMessage.Parts[1].ContentCase);
+        Assert.Equal("please summarize the file content", a2aMessage.Parts[1].Text);
 
-        var thirdTextPart = Assert.IsType<TextPart>(a2aMessage.Parts[2]);
-        Assert.Equal("and send it to me over email", thirdTextPart.Text);
+        Assert.Equal(PartContentCase.Text, a2aMessage.Parts[2].ContentCase);
+        Assert.Equal("and send it to me over email", a2aMessage.Parts[2].Text);
     }
 }

dotnet/tests/Microsoft.Agents.AI.A2A.UnitTests/Microsoft.Agents.AI.A2A.UnitTests.csproj

@@ -1,5 +1,9 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
+  <PropertyGroup>
+    <TargetFrameworks>$(TargetFrameworksCore)</TargetFrameworks>
+  </PropertyGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\..\src\Microsoft.Agents.AI.A2A\Microsoft.Agents.AI.A2A.csproj" />
   </ItemGroup>

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/A2AAgentHandlerTests.cs

@@ -0,0 +1,966 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Tasks;
+using A2A;
+using Microsoft.Extensions.AI;
+using Moq;
+using Moq.Protected;
+
+namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests;
+
+/// <summary>
+/// Unit tests for the <see cref="A2AAgentHandler"/> class.
+/// </summary>
+public sealed class A2AAgentHandlerTests
+{
+    /// <summary>
+    /// Verifies that when metadata is null, the options passed to RunAsync have
+    /// AllowBackgroundResponses disabled and no AdditionalProperties.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_WhenMetadataIsNull_PassesOptionsWithNoAdditionalPropertiesToRunAsync()
+    {
+        // Arrange
+        AgentRunOptions? capturedOptions = null;
+        A2AAgentHandler handler = CreateHandler(CreateAgentMock(options => capturedOptions = options));
+
+        // Act
+        await InvokeExecuteAsync(handler, new RequestContext
+        {
+            TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Assert.NotNull(capturedOptions);
+        Assert.False(capturedOptions.AllowBackgroundResponses);
+        Assert.Null(capturedOptions.AdditionalProperties);
+    }
+
+    /// <summary>
+    /// Verifies that when metadata is non-empty, the options passed to RunAsync have
+    /// AdditionalProperties populated with the converted metadata values.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_WhenMetadataIsNonEmpty_PassesOptionsWithAdditionalPropertiesToRunAsync()
+    {
+        // Arrange
+        AgentRunOptions? capturedOptions = null;
+        A2AAgentHandler handler = CreateHandler(CreateAgentMock(options => capturedOptions = options));
+
+        // Act
+        await InvokeExecuteAsync(handler, new RequestContext
+        {
+            TaskId = "", ContextId = "ctx", StreamingResponse = false,
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] },
+            Metadata = new Dictionary<string, JsonElement>
+            {
+                ["key1"] = JsonSerializer.SerializeToElement("value1"),
+                ["key2"] = JsonSerializer.SerializeToElement(42)
+            }
+        });
+
+        // Assert
+        Assert.NotNull(capturedOptions);
+        Assert.False(capturedOptions.AllowBackgroundResponses);
+        Assert.NotNull(capturedOptions.AdditionalProperties);
+        Assert.Equal(2, capturedOptions.AdditionalProperties.Count);
+        Assert.Equal("value1", capturedOptions.AdditionalProperties["key1"]?.ToString());
+    }
+
+    /// <summary>
+    /// Verifies that when the agent response has AdditionalProperties, the returned Message.Metadata contains the converted values.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_WhenResponseHasAdditionalProperties_ReturnsMessageWithMetadataAsync()
+    {
+        // Arrange
+        AdditionalPropertiesDictionary additionalProps = new()
+        {
+            ["responseKey1"] = "responseValue1",
+            ["responseKey2"] = 123
+        };
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Test response")])
+        {
+            AdditionalProperties = additionalProps
+        };
+        A2AAgentHandler handler = CreateHandler(CreateAgentMockWithResponse(response));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.NotNull(message.Metadata);
+        Assert.Equal(2, message.Metadata.Count);
+        Assert.True(message.Metadata.ContainsKey("responseKey1"));
+        Assert.True(message.Metadata.ContainsKey("responseKey2"));
+    }
+
+    /// <summary>
+    /// Verifies that when the agent response has null AdditionalProperties, the returned Message.Metadata is null.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_WhenResponseHasNullAdditionalProperties_ReturnsMessageWithNullMetadataAsync()
+    {
+        // Arrange
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Test response")])
+        {
+            AdditionalProperties = null
+        };
+        A2AAgentHandler handler = CreateHandler(CreateAgentMockWithResponse(response));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.Null(message.Metadata);
+    }
+
+    /// <summary>
+    /// Verifies that when the agent response has empty AdditionalProperties, the returned Message.Metadata is null.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_WhenResponseHasEmptyAdditionalProperties_ReturnsMessageWithNullMetadataAsync()
+    {
+        // Arrange
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Test response")])
+        {
+            AdditionalProperties = []
+        };
+        A2AAgentHandler handler = CreateHandler(CreateAgentMockWithResponse(response));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.Null(message.Metadata);
+    }
+
+    /// <summary>
+    /// Verifies that when runMode is DisallowBackground, AllowBackgroundResponses is false.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_DisallowBackgroundMode_SetsAllowBackgroundResponsesFalseAsync()
+    {
+        // Arrange
+        AgentRunOptions? capturedOptions = null;
+        A2AAgentHandler handler = CreateHandler(
+            CreateAgentMock(options => capturedOptions = options),
+            runMode: AgentRunMode.DisallowBackground);
+
+        // Act
+        await InvokeExecuteAsync(handler, new RequestContext
+        {
+            TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Assert.NotNull(capturedOptions);
+        Assert.False(capturedOptions.AllowBackgroundResponses);
+    }
+
+    /// <summary>
+    /// Verifies that in AllowBackgroundIfSupported mode, AllowBackgroundResponses is true.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_AllowBackgroundIfSupportedMode_SetsAllowBackgroundResponsesTrueAsync()
+    {
+        // Arrange
+        AgentRunOptions? capturedOptions = null;
+        A2AAgentHandler handler = CreateHandler(
+            CreateAgentMock(options => capturedOptions = options),
+            runMode: AgentRunMode.AllowBackgroundIfSupported);
+
+        // Act
+        await InvokeExecuteAsync(handler, new RequestContext
+        {
+            TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Assert.NotNull(capturedOptions);
+        Assert.True(capturedOptions.AllowBackgroundResponses);
+    }
+
+    /// <summary>
+    /// Verifies that a custom Dynamic delegate returning false sets AllowBackgroundResponses to false.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_DynamicMode_WithFalseCallback_SetsAllowBackgroundResponsesFalseAsync()
+    {
+        // Arrange
+        AgentRunOptions? capturedOptions = null;
+        A2AAgentHandler handler = CreateHandler(
+            CreateAgentMock(options => capturedOptions = options),
+            runMode: AgentRunMode.AllowBackgroundWhen((_, _) => ValueTask.FromResult(false)));
+
+        // Act
+        await InvokeExecuteAsync(handler, new RequestContext
+        {
+            TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Assert.NotNull(capturedOptions);
+        Assert.False(capturedOptions.AllowBackgroundResponses);
+    }
+
+    /// <summary>
+    /// Verifies that a custom Dynamic delegate returning true sets AllowBackgroundResponses to true.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_DynamicMode_WithTrueCallback_SetsAllowBackgroundResponsesTrueAsync()
+    {
+        // Arrange
+        AgentRunOptions? capturedOptions = null;
+        A2AAgentHandler handler = CreateHandler(
+            CreateAgentMock(options => capturedOptions = options),
+            runMode: AgentRunMode.AllowBackgroundWhen((_, _) => ValueTask.FromResult(true)));
+
+        // Act
+        await InvokeExecuteAsync(handler, new RequestContext
+        {
+            TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Assert.NotNull(capturedOptions);
+        Assert.True(capturedOptions.AllowBackgroundResponses);
+    }
+
+#pragma warning disable MEAI001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
+
+    /// <summary>
+    /// Verifies that when the agent returns a ContinuationToken, task status events are emitted.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_WhenResponseHasContinuationToken_EmitsTaskStatusEventsAsync()
+    {
+        // Arrange
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Starting work...")])
+        {
+            ContinuationToken = CreateTestContinuationToken()
+        };
+        A2AAgentHandler handler = CreateHandler(CreateAgentMockWithResponse(response));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = false,
+            TaskId = "task-1",
+            ContextId = "ctx-1",
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert - should have emitted status update events (Submitted + Working)
+        Assert.True(events.StatusUpdates.Count >= 1);
+        Assert.Empty(events.Messages);
+    }
+
+    /// <summary>
+    /// Verifies that when the incoming message has a ContextId, it is used for the response
+    /// rather than generating a new one.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_WhenMessageHasContextId_UsesProvidedContextIdAsync()
+    {
+        // Arrange
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Reply")]);
+        A2AAgentHandler handler = CreateHandler(CreateAgentMockWithResponse(response));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = false,
+            TaskId = "",
+            ContextId = "my-context-123",
+            Message = new Message
+            {
+                MessageId = "test-id",
+                ContextId = "my-context-123",
+                Role = Role.User,
+                Parts = [new Part { Text = "Hello" }]
+            }
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.Equal("my-context-123", message.ContextId);
+    }
+
+    /// <summary>
+    /// Verifies that on continuation when the agent completes (no ContinuationToken), task is completed with artifact.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_OnContinuation_WhenComplete_EmitsArtifactAndCompletedAsync()
+    {
+        // Arrange
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Done!")]);
+        A2AAgentHandler handler = CreateHandler(CreateAgentMockWithResponse(response));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = false,
+            Message = new Message { MessageId = "empty", Role = Role.User, Parts = [] },
+            TaskId = "task-1",
+            ContextId = "ctx-1",
+
+            Task = new AgentTask { Id = "task-1", ContextId = "ctx-1", History = [new Message { Role = Role.User, Parts = [new Part { Text = "Hello" }] }] }
+        });
+
+        // Assert - should have artifact + completed status
+        Assert.True(events.ArtifactUpdates.Count > 0);
+        Assert.True(events.StatusUpdates.Count > 0);
+        Assert.Empty(events.Messages);
+    }
+
+    /// <summary>
+    /// Verifies that when the agent throws during a continuation,
+    /// the handler emits a Failed status and re-throws the exception.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_OnContinuation_WhenAgentThrows_EmitsFailedStatusAsync()
+    {
+        // Arrange
+        int callCount = 0;
+        Mock<AIAgent> agentMock = CreateAgentMockWithCallCount(ref callCount, _ =>
+            throw new InvalidOperationException("Agent failed"));
+        A2AAgentHandler handler = CreateHandler(agentMock);
+
+        // Act & Assert
+        var events = new EventCollector();
+        var eventQueue = new AgentEventQueue();
+        var readerTask = ReadEventsAsync(eventQueue, events);
+        await Assert.ThrowsAsync<InvalidOperationException>(() =>
+            handler.ExecuteAsync(
+                new RequestContext
+                {
+                    StreamingResponse = false,
+                    Message = new Message { MessageId = "empty", Role = Role.User, Parts = [] },
+                    TaskId = "task-1",
+                    ContextId = "ctx-1",
+
+                    Task = new AgentTask { Id = "task-1", ContextId = "ctx-1", History = [new Message { Role = Role.User, Parts = [new Part { Text = "Hello" }] }] }
+                },
+                eventQueue,
+                CancellationToken.None));
+        eventQueue.Complete(null);
+        await readerTask;
+
+        // Assert - should have emitted Failed status
+        Assert.True(events.StatusUpdates.Count > 0);
+    }
+
+    /// <summary>
+    /// Verifies that when the agent throws during a continuation and the cancellation token
+    /// is already cancelled, the handler still emits a Failed status and re-throws the
+    /// original exception (not an OperationCanceledException from FailAsync).
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_OnContinuation_WhenAgentThrowsWithCancelledToken_StillEmitsFailedStatusAsync()
+    {
+        // Arrange
+        int callCount = 0;
+        Mock<AIAgent> agentMock = CreateAgentMockWithCallCount(ref callCount, _ =>
+            throw new InvalidOperationException("Agent failed"));
+        A2AAgentHandler handler = CreateHandler(agentMock);
+
+        using var cts = new CancellationTokenSource();
+        cts.Cancel(); // Pre-cancel the token
+
+        // Act & Assert - the original InvalidOperationException should be thrown, not OperationCanceledException
+        var events = new EventCollector();
+        var eventQueue = new AgentEventQueue();
+        var readerTask = ReadEventsAsync(eventQueue, events);
+        await Assert.ThrowsAsync<InvalidOperationException>(() =>
+            handler.ExecuteAsync(
+                new RequestContext
+                {
+                    StreamingResponse = false,
+                    Message = new Message { MessageId = "empty", Role = Role.User, Parts = [] },
+                    TaskId = "task-1",
+                    ContextId = "ctx-1",
+
+                    Task = new AgentTask { Id = "task-1", ContextId = "ctx-1", History = [new Message { Role = Role.User, Parts = [new Part { Text = "Hello" }] }] }
+                },
+                eventQueue,
+                cts.Token));
+        eventQueue.Complete(null);
+        await readerTask;
+
+        // Assert - should have emitted Failed status even with a cancelled token
+        Assert.True(events.StatusUpdates.Count > 0);
+    }
+
+    /// <summary>
+    /// Verifies that when the agent throws OperationCanceledException during a continuation,
+    /// no Failed status is emitted.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_OnContinuation_WhenOperationCancelled_DoesNotEmitFailedAsync()
+    {
+        // Arrange
+        int callCount = 0;
+        Mock<AIAgent> agentMock = CreateAgentMockWithCallCount(ref callCount, _ =>
+            throw new OperationCanceledException("Cancelled"));
+        A2AAgentHandler handler = CreateHandler(agentMock);
+
+        // Act & Assert
+        var events = new EventCollector();
+        var eventQueue = new AgentEventQueue();
+        var readerTask = ReadEventsAsync(eventQueue, events);
+        await Assert.ThrowsAsync<OperationCanceledException>(() =>
+            handler.ExecuteAsync(
+                new RequestContext
+                {
+                    StreamingResponse = false,
+                    Message = new Message { MessageId = "empty", Role = Role.User, Parts = [] },
+                    TaskId = "task-1",
+                    ContextId = "ctx-1",
+
+                    Task = new AgentTask { Id = "task-1", ContextId = "ctx-1", History = [new Message { Role = Role.User, Parts = [new Part { Text = "Hello" }] }] }
+                },
+                eventQueue,
+                CancellationToken.None));
+        eventQueue.Complete(null);
+        await readerTask;
+
+        // Assert - should NOT have emitted any status (OperationCanceledException is re-thrown without marking Failed)
+        Assert.Empty(events.StatusUpdates);
+    }
+
+    /// <summary>
+    /// Verifies that ReferenceTaskIds throws NotSupportedException.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_WithReferenceTaskIds_ThrowsNotSupportedExceptionAsync()
+    {
+        // Arrange
+        A2AAgentHandler handler = CreateHandler(CreateAgentMock(_ => { }));
+
+        // Act & Assert
+        await Assert.ThrowsAsync<NotSupportedException>(() =>
+            InvokeExecuteAsync(handler, new RequestContext
+            {
+                TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message
+                {
+                    MessageId = "test-id",
+                    Role = Role.User,
+                    Parts = [new Part { Text = "Hello" }],
+                    ReferenceTaskIds = ["other-task-id"]
+                }
+            }));
+    }
+
+    /// <summary>
+    /// Verifies that when ContextId is null, a new one is generated and used in the response.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_WhenContextIdIsNull_GeneratesContextIdAsync()
+    {
+        // Arrange
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Reply")]);
+        A2AAgentHandler handler = CreateHandler(CreateAgentMockWithResponse(response));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = false,
+            TaskId = "",
+            ContextId = null!,
+            Message = new Message
+            {
+                MessageId = "test-id",
+                Role = Role.User,
+                Parts = [new Part { Text = "Hello" }]
+            }
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.NotNull(message.ContextId);
+        Assert.NotEmpty(message.ContextId);
+    }
+
+    /// <summary>
+    /// Verifies that when Message is null, the handler still succeeds with empty chat messages.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_WhenMessageIsNull_SucceedsWithEmptyMessagesAsync()
+    {
+        // Arrange
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Reply")]);
+        A2AAgentHandler handler = CreateHandler(CreateAgentMockWithResponse(response));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = false,
+            TaskId = "",
+            ContextId = "ctx",
+            Message = null!
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.Equal("ctx", message.ContextId);
+    }
+
+    /// <summary>
+    /// Verifies that the dynamic AllowBackgroundWhen delegate receives the correct RequestContext.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_DynamicMode_DelegateReceivesRequestContextAsync()
+    {
+        // Arrange
+        A2ARunDecisionContext? capturedContext = null;
+        A2AAgentHandler handler = CreateHandler(
+            CreateAgentMock(_ => { }),
+            runMode: AgentRunMode.AllowBackgroundWhen((ctx, _) =>
+            {
+                capturedContext = ctx;
+                return ValueTask.FromResult(false);
+            }));
+
+        var requestContext = new RequestContext
+        {
+            TaskId = "my-task", ContextId = "my-ctx", StreamingResponse = false,
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        };
+
+        // Act
+        await InvokeExecuteAsync(handler, requestContext);
+
+        // Assert
+        Assert.NotNull(capturedContext);
+        Assert.Same(requestContext, capturedContext.RequestContext);
+    }
+
+    /// <summary>
+    /// Verifies that CancelAsync emits a Canceled status event.
+    /// </summary>
+    [Fact]
+    public async Task CancelAsync_EmitsCanceledStatusAsync()
+    {
+        // Arrange
+        A2AAgentHandler handler = CreateHandler(CreateAgentMock(_ => { }));
+        var events = new EventCollector();
+        var eventQueue = new AgentEventQueue();
+        var readerTask = ReadEventsAsync(eventQueue, events);
+
+        // Act
+        await handler.CancelAsync(
+            new RequestContext
+            {
+                StreamingResponse = false,
+                Message = new Message { MessageId = "empty", Role = Role.User, Parts = [] },
+                TaskId = "task-1",
+                ContextId = "ctx-1",
+                Task = new AgentTask { Id = "task-1", ContextId = "ctx-1" }
+            },
+            eventQueue,
+            CancellationToken.None);
+
+        // Assert
+        eventQueue.Complete(null);
+        await readerTask;
+        Assert.True(events.StatusUpdates.Count > 0);
+    }
+
+#pragma warning restore MEAI001
+
+    /// <summary>
+    /// Verifies that when no session store is provided, the handler uses InMemoryAgentSessionStore
+    /// and can execute successfully.
+    /// </summary>
+    [Fact]
+    public async Task Handler_WithNullSessionStore_UsesInMemorySessionStoreAndExecutesSuccessfullyAsync()
+    {
+        // Arrange
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Reply")]);
+        A2AAgentHandler handler = CreateHandler(CreateAgentMockWithResponse(response), agentSessionStore: null);
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = false,
+            TaskId = "",
+            ContextId = "ctx-1",
+            Message = new Message
+            {
+                MessageId = "test-id",
+                Role = Role.User,
+                Parts = [new Part { Text = "Hello" }]
+            }
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.Equal("Reply", message.Parts![0].Text);
+    }
+
+    /// <summary>
+    /// Verifies that when a custom session store is provided, it is used instead of the
+    /// default InMemoryAgentSessionStore.
+    /// </summary>
+    [Fact]
+    public async Task Handler_WithCustomSessionStore_UsesProvidedSessionStoreAsync()
+    {
+        // Arrange
+        var mockSessionStore = new Mock<AgentSessionStore>();
+        mockSessionStore
+            .Setup(x => x.GetSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.IsAny<string>(),
+                It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new TestAgentSession());
+        mockSessionStore
+            .Setup(x => x.SaveSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.IsAny<string>(),
+                It.IsAny<AgentSession>(),
+                It.IsAny<CancellationToken>()))
+            .Returns(ValueTask.CompletedTask);
+
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Reply")]);
+        A2AAgentHandler handler = CreateHandler(CreateAgentMockWithResponse(response), agentSessionStore: mockSessionStore.Object);
+
+        // Act
+        await InvokeExecuteAsync(handler, new RequestContext
+        {
+            StreamingResponse = false,
+            TaskId = "",
+            ContextId = "ctx-1",
+            Message = new Message
+            {
+                MessageId = "test-id",
+                Role = Role.User,
+                Parts = [new Part { Text = "Hello" }]
+            }
+        });
+
+        // Assert - verify the custom session store was called
+        mockSessionStore.Verify(
+            x => x.GetSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.Is<string>(s => s == "ctx-1"),
+                It.IsAny<CancellationToken>()),
+            Times.Once);
+        mockSessionStore.Verify(
+            x => x.SaveSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.Is<string>(s => s == "ctx-1"),
+                It.IsAny<AgentSession>(),
+                It.IsAny<CancellationToken>()),
+            Times.Once);
+    }
+
+    /// <summary>
+    /// Verifies that when no session store is provided, the default InMemoryAgentSessionStore
+    /// persists sessions across multiple calls with the same context ID.
+    /// </summary>
+    [Fact]
+    public async Task Handler_WithNullSessionStore_SessionIsPersistedAcrossCallsAsync()
+    {
+        // Arrange - track how many times CreateSessionCoreAsync is called
+        int createSessionCallCount = 0;
+        var sessionInstance = new TestAgentSession();
+
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
+        agentMock
+            .Protected()
+            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
+            .Callback(() => Interlocked.Increment(ref createSessionCallCount))
+            .ReturnsAsync(() => new TestAgentSession());
+        agentMock
+            .Protected()
+            .Setup<ValueTask<JsonElement>>("SerializeSessionCoreAsync",
+                ItExpr.IsAny<AgentSession>(),
+                ItExpr.IsAny<JsonSerializerOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(JsonDocument.Parse("{}").RootElement);
+        agentMock
+            .Protected()
+            .Setup<ValueTask<AgentSession>>("DeserializeSessionCoreAsync",
+                ItExpr.IsAny<JsonElement>(),
+                ItExpr.IsAny<JsonSerializerOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(sessionInstance);
+        agentMock
+            .Protected()
+            .Setup<Task<AgentResponse>>("RunCoreAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentSession?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new AgentResponse([new ChatMessage(ChatRole.Assistant, "Reply")]));
+
+        A2AAgentHandler handler = CreateHandler(agentMock, agentSessionStore: null);
+
+        var context = new RequestContext
+        {
+            StreamingResponse = false,
+            TaskId = "",
+            ContextId = "ctx-persistent",
+            Message = new Message
+            {
+                MessageId = "test-id",
+                Role = Role.User,
+                Parts = [new Part { Text = "Hello" }]
+            }
+        };
+
+        // Act - call twice with the same context ID
+        await InvokeExecuteAsync(handler, context);
+        await InvokeExecuteAsync(handler, context);
+
+        // Assert - CreateSessionCoreAsync should be called once (first call creates, second retrieves from store)
+        Assert.Equal(1, createSessionCallCount);
+    }
+
+    /// <summary>
+    /// Verifies that when the AllowBackgroundWhen delegate throws, the exception propagates
+    /// and the agent is not invoked.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_DynamicMode_WhenCallbackThrows_PropagatesExceptionAsync()
+    {
+        // Arrange
+        bool agentInvoked = false;
+        A2AAgentHandler handler = CreateHandler(
+            CreateAgentMock(_ => agentInvoked = true),
+            runMode: AgentRunMode.AllowBackgroundWhen((_, _) =>
+                throw new InvalidOperationException("Callback failed")));
+
+        // Act & Assert
+        await Assert.ThrowsAsync<InvalidOperationException>(() =>
+            InvokeExecuteAsync(handler, new RequestContext
+            {
+                TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+            }));
+
+        Assert.False(agentInvoked);
+    }
+
+    /// <summary>
+    /// Verifies that the CancellationToken is propagated to the AllowBackgroundWhen delegate.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_DynamicMode_CancellationTokenIsPropagatedToCallbackAsync()
+    {
+        // Arrange
+        CancellationToken capturedToken = default;
+        using var cts = new CancellationTokenSource();
+        A2AAgentHandler handler = CreateHandler(
+            CreateAgentMock(_ => { }),
+            runMode: AgentRunMode.AllowBackgroundWhen((_, ct) =>
+            {
+                capturedToken = ct;
+                return ValueTask.FromResult(false);
+            }));
+
+        // Act
+        var eventQueue = new AgentEventQueue();
+        await handler.ExecuteAsync(
+            new RequestContext
+            {
+                TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+            },
+            eventQueue,
+            cts.Token);
+        eventQueue.Complete(null);
+
+        // Assert
+        Assert.Equal(cts.Token, capturedToken);
+    }
+
+    /// <summary>
+    /// Verifies that the agent run mode is applied on the continuation/task-update path,
+    /// not just the new message path.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_OnContinuation_RunModeIsAppliedAsync()
+    {
+        // Arrange
+        AgentRunOptions? capturedOptions = null;
+        A2AAgentHandler handler = CreateHandler(
+            CreateAgentMock(options => capturedOptions = options),
+            runMode: AgentRunMode.AllowBackgroundIfSupported);
+
+        // Act
+        await InvokeExecuteAsync(handler, new RequestContext
+        {
+            StreamingResponse = false,
+            TaskId = "task-1",
+            ContextId = "ctx-1",
+            Message = new Message { MessageId = "empty", Role = Role.User, Parts = [] },
+
+            Task = new AgentTask { Id = "task-1", ContextId = "ctx-1", History = [new Message { Role = Role.User, Parts = [new Part { Text = "Hello" }] }] }
+        });
+
+        // Assert
+        Assert.NotNull(capturedOptions);
+        Assert.True(capturedOptions.AllowBackgroundResponses);
+    }
+
+    private static A2AAgentHandler CreateHandler(
+        Mock<AIAgent> agentMock,
+        AgentRunMode? runMode = null,
+        AgentSessionStore? agentSessionStore = null)
+    {
+        runMode ??= AgentRunMode.DisallowBackground;
+
+        var hostAgent = new AIHostAgent(
+            innerAgent: agentMock.Object,
+            sessionStore: agentSessionStore ?? new InMemoryAgentSessionStore());
+
+        return new A2AAgentHandler(hostAgent, runMode);
+    }
+
+    private static Mock<AIAgent> CreateAgentMock(Action<AgentRunOptions?> optionsCallback)
+    {
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
+        agentMock
+            .Protected()
+            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new TestAgentSession());
+        agentMock
+            .Protected()
+            .Setup<Task<AgentResponse>>("RunCoreAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentSession?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .Callback<IEnumerable<ChatMessage>, AgentSession?, AgentRunOptions?, CancellationToken>(
+                (_, _, options, _) => optionsCallback(options))
+            .ReturnsAsync(new AgentResponse([new ChatMessage(ChatRole.Assistant, "Test response")]));
+
+        return agentMock;
+    }
+
+    private static Mock<AIAgent> CreateAgentMockWithResponse(AgentResponse response)
+    {
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
+        agentMock
+            .Protected()
+            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new TestAgentSession());
+        agentMock
+            .Protected()
+            .Setup<Task<AgentResponse>>("RunCoreAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentSession?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(response);
+
+        return agentMock;
+    }
+
+    private static Mock<AIAgent> CreateAgentMockWithCallCount(
+        ref int callCount,
+        Func<int, AgentResponse> responseFactory)
+    {
+        StrongBox<int> callCountBox = new(callCount);
+
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
+        agentMock
+            .Protected()
+            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new TestAgentSession());
+        agentMock
+            .Protected()
+            .Setup<Task<AgentResponse>>("RunCoreAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentSession?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(() =>
+            {
+                int currentCall = Interlocked.Increment(ref callCountBox.Value);
+                return responseFactory(currentCall);
+            });
+
+        return agentMock;
+    }
+
+    private static async Task InvokeExecuteAsync(A2AAgentHandler handler, RequestContext context)
+    {
+        var eventQueue = new AgentEventQueue();
+        await handler.ExecuteAsync(context, eventQueue, CancellationToken.None);
+        eventQueue.Complete(null);
+    }
+
+    private static async Task<EventCollector> CollectEventsAsync(A2AAgentHandler handler, RequestContext context)
+    {
+        var events = new EventCollector();
+        var eventQueue = new AgentEventQueue();
+        var readerTask = ReadEventsAsync(eventQueue, events);
+
+        await handler.ExecuteAsync(context, eventQueue, CancellationToken.None);
+        eventQueue.Complete(null);
+        await readerTask;
+
+        return events;
+    }
+
+    private static async Task ReadEventsAsync(AgentEventQueue eventQueue, EventCollector collector)
+    {
+        await foreach (var response in eventQueue)
+        {
+            switch (response.PayloadCase)
+            {
+                case StreamResponseCase.Message:
+                    collector.Messages.Add(response.Message!);
+                    break;
+                case StreamResponseCase.Task:
+                    collector.Tasks.Add(response.Task!);
+                    break;
+                case StreamResponseCase.StatusUpdate:
+                    collector.StatusUpdates.Add(response.StatusUpdate!);
+                    break;
+                case StreamResponseCase.ArtifactUpdate:
+                    collector.ArtifactUpdates.Add(response.ArtifactUpdate!);
+                    break;
+            }
+        }
+    }
+
+#pragma warning disable MEAI001
+    private static ResponseContinuationToken CreateTestContinuationToken()
+    {
+        return ResponseContinuationToken.FromBytes(new byte[] { 0x01, 0x02, 0x03 });
+    }
+#pragma warning restore MEAI001
+
+    private sealed class EventCollector
+    {
+        public List<Message> Messages { get; } = [];
+        public List<AgentTask> Tasks { get; } = [];
+        public List<TaskStatusUpdateEvent> StatusUpdates { get; } = [];
+        public List<TaskArtifactUpdateEvent> ArtifactUpdates { get; } = [];
+    }
+
+    private sealed class TestAgentSession : AgentSession;
+}

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/A2AEndpointRouteBuilderExtensionsTests.cs

@@ -0,0 +1,559 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using Microsoft.Agents.AI.Hosting.A2A.UnitTests.Internal;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.AI;
+using Microsoft.Extensions.DependencyInjection;
+using Moq;
+
+namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests;
+
+/// <summary>
+/// Tests for A2AEndpointRouteBuilderExtensions and A2AServerServiceCollectionExtensions methods.
+/// </summary>
+public sealed class A2AEndpointRouteBuilderExtensionsTests
+{
+    /// <summary>
+    /// Verifies that MapA2AHttpJson throws ArgumentNullException for null endpoints.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_WithAgentBuilder_NullEndpoints_ThrowsArgumentNullException()
+    {
+        // Arrange
+        AspNetCore.Routing.IEndpointRouteBuilder endpoints = null!;
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            endpoints.MapA2AHttpJson(agentBuilder, "/a2a"));
+
+        Assert.Equal("endpoints", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AHttpJson throws ArgumentNullException for null agentBuilder.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_WithAgentBuilder_NullAgentBuilder_ThrowsArgumentNullException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+        IHostedAgentBuilder agentBuilder = null!;
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            app.MapA2AHttpJson(agentBuilder, "/a2a"));
+
+        Assert.Equal("agentBuilder", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AHttpJson with IHostedAgentBuilder correctly maps the agent with default configuration.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_WithAgentBuilder_DefaultConfiguration_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        agentBuilder.AddA2AServer();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2AHttpJson(agentBuilder, "/a2a");
+        Assert.NotNull(result);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AHttpJson with string agent name correctly maps the agent.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_WithAgentName_DefaultConfiguration_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddA2AServer("agent");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2AHttpJson("agent", "/a2a");
+        Assert.NotNull(result);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AJsonRpc with IHostedAgentBuilder correctly maps the agent.
+    /// </summary>
+    [Fact]
+    public void MapA2AJsonRpc_WithAgentBuilder_DefaultConfiguration_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        agentBuilder.AddA2AServer();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2AJsonRpc(agentBuilder, "/a2a");
+        Assert.NotNull(result);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AJsonRpc with string agent name correctly maps the agent.
+    /// </summary>
+    [Fact]
+    public void MapA2AJsonRpc_WithAgentName_DefaultConfiguration_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddA2AServer("agent");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2AJsonRpc("agent", "/a2a");
+        Assert.NotNull(result);
+    }
+
+    /// <summary>
+    /// Verifies that both MapA2AHttpJson and MapA2AJsonRpc can be called for the same agent.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_And_MapA2AJsonRpc_SameAgent_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        agentBuilder.AddA2AServer();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        var httpResult = app.MapA2AHttpJson(agentBuilder, "/a2a");
+        var rpcResult = app.MapA2AJsonRpc(agentBuilder, "/a2a");
+        Assert.NotNull(httpResult);
+        Assert.NotNull(rpcResult);
+    }
+
+    /// <summary>
+    /// Verifies that multiple agents can be mapped to different paths.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_MultipleAgents_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agent1Builder = builder.AddAIAgent("agent1", "Instructions1", chatClientServiceKey: "chat-client");
+        IHostedAgentBuilder agent2Builder = builder.AddAIAgent("agent2", "Instructions2", chatClientServiceKey: "chat-client");
+        agent1Builder.AddA2AServer();
+        agent2Builder.AddA2AServer();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        app.MapA2AHttpJson(agent1Builder, "/a2a/agent1");
+        app.MapA2AHttpJson(agent2Builder, "/a2a/agent2");
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that custom paths can be specified for A2A endpoints.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_WithCustomPath_AcceptsValidPath()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        agentBuilder.AddA2AServer();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        app.MapA2AHttpJson(agentBuilder, "/custom/a2a/path");
+        Assert.NotNull(app);
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer with custom A2AServerRegistrationOptions succeeds.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_WithCustomOptions_Succeeds()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        agentBuilder.AddA2AServer(options => options.AgentRunMode = AgentRunMode.AllowBackgroundIfSupported);
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert - Should not throw
+        var result = app.MapA2AHttpJson(agentBuilder, "/a2a");
+        Assert.NotNull(result);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AHttpJson throws ArgumentNullException for null endpoints when using string agent name.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_WithAgentName_NullEndpoints_ThrowsArgumentNullException()
+    {
+        // Arrange
+        AspNetCore.Routing.IEndpointRouteBuilder endpoints = null!;
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            endpoints.MapA2AHttpJson("agent", "/a2a"));
+
+        Assert.Equal("endpoints", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AJsonRpc throws ArgumentNullException for null endpoints when using string agent name.
+    /// </summary>
+    [Fact]
+    public void MapA2AJsonRpc_WithAgentName_NullEndpoints_ThrowsArgumentNullException()
+    {
+        // Arrange
+        AspNetCore.Routing.IEndpointRouteBuilder endpoints = null!;
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            endpoints.MapA2AJsonRpc("agent", "/a2a"));
+
+        Assert.Equal("endpoints", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AHttpJson throws ArgumentNullException for null agentName.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_WithAgentName_NullAgentName_ThrowsArgumentNullException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            app.MapA2AHttpJson((string)null!, "/a2a"));
+
+        Assert.Equal("agentName", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AHttpJson throws ArgumentException for empty agentName.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_WithAgentName_EmptyAgentName_ThrowsArgumentException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert
+        ArgumentException exception = Assert.Throws<ArgumentException>(() =>
+            app.MapA2AHttpJson(string.Empty, "/a2a"));
+
+        Assert.Equal("agentName", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AHttpJson throws ArgumentNullException for null path.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_NullPath_ThrowsArgumentNullException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        agentBuilder.AddA2AServer();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert
+        Assert.Throws<ArgumentNullException>(() =>
+            app.MapA2AHttpJson(agentBuilder, null!));
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AHttpJson throws ArgumentException for whitespace-only path.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_WhitespacePath_ThrowsArgumentException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        agentBuilder.AddA2AServer();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert
+        Assert.Throws<ArgumentException>(() =>
+            app.MapA2AHttpJson(agentBuilder, "   "));
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer throws ArgumentNullException for null services.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_NullServices_ThrowsArgumentNullException()
+    {
+        // Arrange
+        IServiceCollection services = null!;
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            services.AddA2AServer("agent"));
+
+        Assert.Equal("services", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer throws ArgumentNullException for null agentName.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_NullAgentName_ThrowsArgumentNullException()
+    {
+        // Arrange
+        IServiceCollection services = new ServiceCollection();
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            services.AddA2AServer((string)null!));
+
+        Assert.Equal("agentName", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer throws ArgumentException for empty agentName.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_EmptyAgentName_ThrowsArgumentException()
+    {
+        // Arrange
+        IServiceCollection services = new ServiceCollection();
+
+        // Act & Assert
+        ArgumentException exception = Assert.Throws<ArgumentException>(() =>
+            services.AddA2AServer(string.Empty));
+
+        Assert.Equal("agentName", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer on IHostedAgentBuilder throws ArgumentNullException for null builder.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_NullAgentBuilder_ThrowsArgumentNullException()
+    {
+        // Arrange
+        IHostedAgentBuilder agentBuilder = null!;
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            agentBuilder.AddA2AServer());
+
+        Assert.Equal("agentBuilder", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AHttpJson throws ArgumentNullException for null AIAgent.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_WithAIAgent_NullAgent_ThrowsArgumentNullException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+        AIAgent agent = null!;
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            app.MapA2AHttpJson(agent, "/a2a"));
+
+        Assert.Equal("agent", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AHttpJson throws ArgumentNullException for AIAgent with null Name.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_WithAIAgent_NullName_ThrowsArgumentException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+        var agentMock = new Mock<AIAgent>();
+        agentMock.Setup(a => a.Name).Returns((string?)null);
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            app.MapA2AHttpJson(agentMock.Object, "/a2a"));
+
+        Assert.Equal("agent.Name", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AHttpJson throws ArgumentException for AIAgent with whitespace Name.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_WithAIAgent_WhitespaceName_ThrowsArgumentException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+        var agentMock = new Mock<AIAgent>();
+        agentMock.Setup(a => a.Name).Returns("   ");
+
+        // Act & Assert
+        ArgumentException exception = Assert.Throws<ArgumentException>(() =>
+            app.MapA2AHttpJson(agentMock.Object, "/a2a"));
+
+        Assert.Equal("agent.Name", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AJsonRpc throws ArgumentNullException for null AIAgent.
+    /// </summary>
+    [Fact]
+    public void MapA2AJsonRpc_WithAIAgent_NullAgent_ThrowsArgumentNullException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+        AIAgent agent = null!;
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            app.MapA2AJsonRpc(agent, "/a2a"));
+
+        Assert.Equal("agent", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AJsonRpc throws ArgumentNullException for AIAgent with null Name.
+    /// </summary>
+    [Fact]
+    public void MapA2AJsonRpc_WithAIAgent_NullName_ThrowsArgumentException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+        var agentMock = new Mock<AIAgent>();
+        agentMock.Setup(a => a.Name).Returns((string?)null);
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            app.MapA2AJsonRpc(agentMock.Object, "/a2a"));
+
+        Assert.Equal("agent.Name", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AJsonRpc throws ArgumentException for AIAgent with whitespace Name.
+    /// </summary>
+    [Fact]
+    public void MapA2AJsonRpc_WithAIAgent_WhitespaceName_ThrowsArgumentException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+        var agentMock = new Mock<AIAgent>();
+        agentMock.Setup(a => a.Name).Returns("   ");
+
+        // Act & Assert
+        ArgumentException exception = Assert.Throws<ArgumentException>(() =>
+            app.MapA2AJsonRpc(agentMock.Object, "/a2a"));
+
+        Assert.Equal("agent.Name", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AHttpJson throws InvalidOperationException when no A2AServer has been
+    /// registered for the specified agent via AddA2AServer.
+    /// </summary>
+    [Fact]
+    public void MapA2AHttpJson_WithoutAddA2AServer_ThrowsInvalidOperationException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert
+        InvalidOperationException exception = Assert.Throws<InvalidOperationException>(() =>
+            app.MapA2AHttpJson("agent", "/a2a"));
+
+        Assert.Contains("agent", exception.Message);
+        Assert.Contains("AddA2AServer", exception.Message);
+    }
+
+    /// <summary>
+    /// Verifies that MapA2AJsonRpc throws InvalidOperationException when no A2AServer has been
+    /// registered for the specified agent via AddA2AServer.
+    /// </summary>
+    [Fact]
+    public void MapA2AJsonRpc_WithoutAddA2AServer_ThrowsInvalidOperationException()
+    {
+        // Arrange
+        WebApplicationBuilder builder = WebApplication.CreateBuilder();
+        IChatClient mockChatClient = new DummyChatClient();
+        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
+        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
+        builder.Services.AddLogging();
+        using WebApplication app = builder.Build();
+
+        // Act & Assert
+        InvalidOperationException exception = Assert.Throws<InvalidOperationException>(() =>
+            app.MapA2AJsonRpc("agent", "/a2a"));
+
+        Assert.Contains("agent", exception.Message);
+        Assert.Contains("AddA2AServer", exception.Message);
+    }
+}

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/A2AIntegrationTests.cs

@@ -1,89 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-
-using System;
-using System.Text.Json;
-using System.Threading.Tasks;
-using A2A;
-using Microsoft.Agents.AI.Hosting.A2A.UnitTests.Internal;
-using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Hosting.Server;
-using Microsoft.AspNetCore.TestHost;
-using Microsoft.Extensions.AI;
-using Microsoft.Extensions.DependencyInjection;
-
-namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests;
-
-public sealed class A2AIntegrationTests
-{
-    /// <summary>
-    /// Verifies that calling the A2A card endpoint with MapA2A returns an agent card with a URL populated.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_WithAgentCard_CardEndpointReturnsCardWithUrlAsync()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        builder.WebHost.UseTestServer();
-
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("test-agent", "Test instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-
-        using WebApplication app = builder.Build();
-
-        var agentCard = new AgentCard
-        {
-            Name = "Test Agent",
-            Description = "A test agent for A2A communication",
-            Version = "1.0"
-        };
-
-        // Map A2A with the agent card
-        app.MapA2A(agentBuilder, "/a2a/test-agent", agentCard);
-
-        await app.StartAsync();
-
-        try
-        {
-            // Get the test server client
-            TestServer testServer = app.Services.GetRequiredService<IServer>() as TestServer
-                ?? throw new InvalidOperationException("TestServer not found");
-            var httpClient = testServer.CreateClient();
-
-            // Act - Query the agent card endpoint
-            var requestUri = new Uri("/a2a/test-agent/v1/card", UriKind.Relative);
-            var response = await httpClient.GetAsync(requestUri);
-
-            // Assert
-            Assert.True(response.IsSuccessStatusCode, $"Expected successful response but got {response.StatusCode}");
-
-            var content = await response.Content.ReadAsStringAsync();
-            var jsonDoc = JsonDocument.Parse(content);
-            var root = jsonDoc.RootElement;
-
-            // Verify the card has expected properties
-            Assert.True(root.TryGetProperty("name", out var nameProperty));
-            Assert.Equal("Test Agent", nameProperty.GetString());
-
-            Assert.True(root.TryGetProperty("description", out var descProperty));
-            Assert.Equal("A test agent for A2A communication", descProperty.GetString());
-
-            // Verify the card has a URL property and it's not null/empty
-            Assert.True(root.TryGetProperty("url", out var urlProperty));
-            Assert.NotEqual(JsonValueKind.Null, urlProperty.ValueKind);
-
-            var url = urlProperty.GetString();
-            Assert.NotNull(url);
-            Assert.NotEmpty(url);
-            Assert.StartsWith("http", url, StringComparison.OrdinalIgnoreCase);
-
-            // agentCard's URL matches the agent endpoint
-            Assert.Equal($"{testServer.BaseAddress.ToString().TrimEnd('/')}/a2a/test-agent", url);
-        }
-        finally
-        {
-            await app.StopAsync();
-        }
-    }
-}

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/A2AServerServiceCollectionExtensionsTests.cs

@@ -0,0 +1,459 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Tasks;
+using A2A;
+using Microsoft.Extensions.AI;
+using Microsoft.Extensions.DependencyInjection;
+using Moq;
+using Moq.Protected;
+
+namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests;
+
+/// <summary>
+/// Unit tests for the <see cref="A2AServerServiceCollectionExtensions"/> class.
+/// </summary>
+public sealed class A2AServerServiceCollectionExtensionsTests
+{
+    /// <summary>
+    /// Verifies that AddA2AServer with an agent name registers a keyed A2AServer
+    /// that can be resolved from the service provider.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithAgentName_ResolvesKeyedA2AServerAsync()
+    {
+        // Arrange
+        const string AgentName = "test-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        // Act
+        services.AddA2AServer(AgentName);
+
+        // Assert
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer with an agent instance registers a keyed A2AServer
+    /// that can be resolved from the service provider using the agent's name.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithAgentInstance_ResolvesKeyedA2AServerAsync()
+    {
+        // Arrange
+        const string AgentName = "instance-agent";
+        var agentMock = CreateAgentMock(AgentName);
+        var services = new ServiceCollection();
+
+        // Act
+        services.AddA2AServer(agentMock.Object);
+
+        // Assert
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that when no ITaskStore or AgentSessionStore are registered,
+    /// AddA2AServer falls back to in-memory defaults and resolves successfully.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithNoCustomStores_FallsBackToInMemoryDefaultsAsync()
+    {
+        // Arrange
+        const string AgentName = "default-stores-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        // Act
+        services.AddA2AServer(AgentName);
+
+        // Assert - resolution succeeds without any stores registered
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that when a custom ITaskStore is registered, AddA2AServer uses it
+    /// instead of the default InMemoryTaskStore.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithCustomTaskStore_ResolvesSuccessfullyAsync()
+    {
+        // Arrange
+        const string AgentName = "custom-taskstore-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        var mockTaskStore = new Mock<ITaskStore>();
+        services.AddKeyedSingleton(AgentName, mockTaskStore.Object);
+
+        // Act
+        services.AddA2AServer(AgentName);
+
+        // Assert
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that when a custom AgentSessionStore is registered, AddA2AServer uses it
+    /// instead of the default InMemoryAgentSessionStore.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithCustomAgentSessionStore_ResolvesSuccessfullyAsync()
+    {
+        // Arrange
+        const string AgentName = "custom-sessionstore-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        var mockSessionStore = new Mock<AgentSessionStore>();
+        services.AddKeyedSingleton(AgentName, mockSessionStore.Object);
+
+        // Act
+        services.AddA2AServer(AgentName);
+
+        // Assert
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that when a custom IAgentHandler is registered, AddA2AServer uses it
+    /// instead of creating a default A2AAgentHandler.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithCustomAgentHandler_ResolvesSuccessfullyAsync()
+    {
+        // Arrange
+        const string AgentName = "custom-handler-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        var mockHandler = new Mock<IAgentHandler>();
+        services.AddKeyedSingleton(AgentName, mockHandler.Object);
+
+        // Act
+        services.AddA2AServer(AgentName);
+
+        // Assert
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that the configureOptions callback is invoked when provided.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithConfigureOptions_InvokesCallbackAsync()
+    {
+        // Arrange
+        const string AgentName = "options-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        bool callbackInvoked = false;
+
+        // Act
+        services.AddA2AServer(AgentName, options =>
+        {
+            callbackInvoked = true;
+            options.AgentRunMode = AgentRunMode.AllowBackgroundIfSupported;
+        });
+
+        // Assert - callback is invoked during resolution
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+        Assert.True(callbackInvoked);
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer with a null configureOptions does not throw.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithNullConfigureOptions_ResolvesSuccessfullyAsync()
+    {
+        // Arrange
+        const string AgentName = "null-options-agent";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        // Act
+        services.AddA2AServer(AgentName, configureOptions: null);
+
+        // Assert
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetKeyedService<A2AServer>(AgentName);
+        Assert.NotNull(server);
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer throws when the agent name is null.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_WithNullAgentName_ThrowsArgumentException()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+
+        // Act & Assert
+        Assert.ThrowsAny<ArgumentException>(() => services.AddA2AServer(agentName: null!));
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer throws when the agent name is whitespace.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_WithWhitespaceAgentName_ThrowsArgumentException()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+
+        // Act & Assert
+        Assert.ThrowsAny<ArgumentException>(() => services.AddA2AServer(agentName: "  "));
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer throws when the services parameter is null.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_WithNullServices_ThrowsArgumentNullException()
+    {
+        // Arrange
+        IServiceCollection services = null!;
+
+        // Act & Assert
+        Assert.Throws<ArgumentNullException>(() => services.AddA2AServer("agent"));
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer with an agent instance throws when the agent is null.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_WithNullAgent_ThrowsArgumentNullException()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+
+        // Act & Assert
+        Assert.Throws<ArgumentNullException>(() => services.AddA2AServer(agent: null!));
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer with an agent instance throws when the agent's Name is null.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_WithAgent_NullName_ThrowsArgumentNullException()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        var agentMock = new Mock<AIAgent>();
+        agentMock.Setup(a => a.Name).Returns((string?)null);
+
+        // Act & Assert
+        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
+            services.AddA2AServer(agentMock.Object));
+
+        Assert.Equal("agent.Name", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that AddA2AServer with an agent instance throws when the agent's Name is whitespace.
+    /// </summary>
+    [Fact]
+    public void AddA2AServer_WithAgent_WhitespaceName_ThrowsArgumentException()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        var agentMock = new Mock<AIAgent>();
+        agentMock.Setup(a => a.Name).Returns("   ");
+
+        // Act & Assert
+        ArgumentException exception = Assert.Throws<ArgumentException>(() =>
+            services.AddA2AServer(agentMock.Object));
+
+        Assert.Equal("agent.Name", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verifies that when a custom <see cref="IAgentHandler"/> is registered as a keyed service,
+    /// the <see cref="A2AServer"/> uses it to process requests instead of the default handler.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithCustomHandler_CustomHandlerIsInvokedOnRequestAsync()
+    {
+        // Arrange
+        const string AgentName = "custom-handler-wiring";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        var mockHandler = new Mock<IAgentHandler>();
+        mockHandler
+            .Setup(h => h.ExecuteAsync(
+                It.IsAny<RequestContext>(),
+                It.IsAny<AgentEventQueue>(),
+                It.IsAny<CancellationToken>()))
+            .Returns((RequestContext _, AgentEventQueue eq, CancellationToken ct) =>
+                eq.EnqueueMessageAsync(
+                    new Message { MessageId = "resp", Role = Role.Agent, Parts = [new Part { Text = "Reply" }] }, ct).AsTask());
+
+        services.AddKeyedSingleton(AgentName, mockHandler.Object);
+
+        services.AddA2AServer(AgentName);
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetRequiredKeyedService<A2AServer>(AgentName);
+
+        // Act
+        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
+        var response = await server.SendMessageAsync(CreateTestSendMessageRequest(), cts.Token);
+
+        // Assert - the custom handler was invoked, not the default A2AAgentHandler
+        mockHandler.Verify(
+            h => h.ExecuteAsync(
+                It.IsAny<RequestContext>(),
+                It.IsAny<AgentEventQueue>(),
+                It.IsAny<CancellationToken>()),
+            Times.Once);
+        Assert.Equal(SendMessageResponseCase.Message, response.PayloadCase);
+        Assert.NotNull(response.Message);
+    }
+
+    /// <summary>
+    /// Verifies that when a custom <see cref="AgentSessionStore"/> is registered as a keyed service
+    /// and no custom <see cref="IAgentHandler"/> is registered, the default handler uses the custom
+    /// session store for session management during request processing.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithCustomSessionStore_NoHandler_SessionStoreIsUsedOnRequestAsync()
+    {
+        // Arrange
+        const string AgentName = "custom-sessionstore-wiring";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMock(AgentName).Object);
+
+        var mockSessionStore = new Mock<AgentSessionStore>();
+        mockSessionStore
+            .Setup(x => x.GetSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.IsAny<string>(),
+                It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new TestAgentSession());
+        mockSessionStore
+            .Setup(x => x.SaveSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.IsAny<string>(),
+                It.IsAny<AgentSession>(),
+                It.IsAny<CancellationToken>()))
+            .Returns(ValueTask.CompletedTask);
+
+        services.AddKeyedSingleton(AgentName, mockSessionStore.Object);
+
+        services.AddA2AServer(AgentName);
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetRequiredKeyedService<A2AServer>(AgentName);
+
+        // Act
+        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
+        var response = await server.SendMessageAsync(CreateTestSendMessageRequest(), cts.Token);
+
+        // Assert - the custom session store was used, not InMemoryAgentSessionStore
+        mockSessionStore.Verify(
+            x => x.GetSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.IsAny<string>(),
+                It.IsAny<CancellationToken>()),
+            Times.Once);
+        Assert.Equal(SendMessageResponseCase.Message, response.PayloadCase);
+        Assert.NotNull(response.Message);
+    }
+
+    /// <summary>
+    /// Verifies that when no custom stores or handlers are registered, the server uses
+    /// the default in-memory stores and processes requests successfully end-to-end.
+    /// </summary>
+    [Fact]
+    public async Task AddA2AServer_WithNoCustomStores_DefaultStoresProcessRequestSuccessfullyAsync()
+    {
+        // Arrange
+        const string AgentName = "default-stores-request";
+        var services = new ServiceCollection();
+        services.AddKeyedSingleton(AgentName, (_, _) => CreateAgentMockForRequests(AgentName).Object);
+
+        services.AddA2AServer(AgentName);
+        await using var provider = services.BuildServiceProvider();
+        var server = provider.GetRequiredKeyedService<A2AServer>(AgentName);
+
+        // Act
+        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
+        var response = await server.SendMessageAsync(CreateTestSendMessageRequest(), cts.Token);
+
+        // Assert - request was processed successfully with default in-memory stores
+        Assert.NotNull(response);
+        Assert.Equal(SendMessageResponseCase.Message, response.PayloadCase);
+        Assert.NotNull(response.Message);
+    }
+
+    private static SendMessageRequest CreateTestSendMessageRequest() =>
+        new()
+        {
+            Message = new Message
+            {
+                MessageId = "test-id",
+                Role = Role.User,
+                Parts = [new Part { Text = "Hello" }]
+            }
+        };
+
+    private static Mock<AIAgent> CreateAgentMock(string name)
+    {
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns(name);
+        agentMock
+            .Protected()
+            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new TestAgentSession());
+        agentMock
+            .Protected()
+            .Setup<Task<AgentResponse>>("RunCoreAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentSession?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new AgentResponse([new ChatMessage(ChatRole.Assistant, "Test response")]));
+
+        return agentMock;
+    }
+
+    /// <summary>
+    /// Creates a mock <see cref="AIAgent"/> with session serialization support, suitable for
+    /// tests that exercise the full request processing path with <see cref="InMemoryAgentSessionStore"/>.
+    /// </summary>
+    private static Mock<AIAgent> CreateAgentMockForRequests(string name)
+    {
+        Mock<AIAgent> agentMock = CreateAgentMock(name);
+        agentMock
+            .Protected()
+            .Setup<ValueTask<JsonElement>>("SerializeSessionCoreAsync",
+                ItExpr.IsAny<AgentSession>(),
+                ItExpr.IsAny<JsonSerializerOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(JsonDocument.Parse("{}").RootElement);
+
+        return agentMock;
+    }
+
+    private sealed class TestAgentSession : AgentSession;
+}

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/AIAgentExtensionsTests.cs

@@ -1,866 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-
-using System;
-using System.Collections.Generic;
-using System.Runtime.CompilerServices;
-using System.Text.Json;
-using System.Threading;
-using System.Threading.Tasks;
-using A2A;
-using Microsoft.Extensions.AI;
-using Moq;
-using Moq.Protected;
-
-namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests;
-
-/// <summary>
-/// Unit tests for the <see cref="AIAgentExtensions"/> class.
-/// </summary>
-public sealed class AIAgentExtensionsTests
-{
-    /// <summary>
-    /// Verifies that when messageSendParams.Metadata is null, the options passed to RunAsync have
-    /// AllowBackgroundResponses enabled and no AdditionalProperties.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_WhenMetadataIsNull_PassesOptionsWithNoAdditionalPropertiesToRunAsync()
-    {
-        // Arrange
-        AgentRunOptions? capturedOptions = null;
-        ITaskManager taskManager = CreateAgentMock(options => capturedOptions = options).Object.MapA2A();
-
-        // Act
-        await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] },
-            Metadata = null
-        });
-
-        // Assert
-        Assert.NotNull(capturedOptions);
-        Assert.False(capturedOptions.AllowBackgroundResponses);
-        Assert.Null(capturedOptions.AdditionalProperties);
-    }
-
-    /// <summary>
-    /// Verifies that when messageSendParams.Metadata has values, the options.AdditionalProperties contains the converted values.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_WhenMetadataHasValues_PassesOptionsWithAdditionalPropertiesToRunAsync()
-    {
-        // Arrange
-        AgentRunOptions? capturedOptions = null;
-        ITaskManager taskManager = CreateAgentMock(options => capturedOptions = options).Object.MapA2A();
-
-        // Act
-        await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] },
-            Metadata = new Dictionary<string, JsonElement>
-            {
-                ["key1"] = JsonSerializer.SerializeToElement("value1"),
-                ["key2"] = JsonSerializer.SerializeToElement(42)
-            }
-        });
-
-        // Assert
-        Assert.NotNull(capturedOptions);
-        Assert.NotNull(capturedOptions.AdditionalProperties);
-        Assert.Equal(2, capturedOptions.AdditionalProperties.Count);
-        Assert.True(capturedOptions.AdditionalProperties.ContainsKey("key1"));
-        Assert.True(capturedOptions.AdditionalProperties.ContainsKey("key2"));
-    }
-
-    /// <summary>
-    /// Verifies that when messageSendParams.Metadata is an empty dictionary, the options passed to RunAsync have
-    /// AllowBackgroundResponses enabled and no AdditionalProperties.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_WhenMetadataIsEmptyDictionary_PassesOptionsWithNoAdditionalPropertiesToRunAsync()
-    {
-        // Arrange
-        AgentRunOptions? capturedOptions = null;
-        ITaskManager taskManager = CreateAgentMock(options => capturedOptions = options).Object.MapA2A();
-
-        // Act
-        await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] },
-            Metadata = []
-        });
-
-        // Assert
-        Assert.NotNull(capturedOptions);
-        Assert.False(capturedOptions.AllowBackgroundResponses);
-        Assert.Null(capturedOptions.AdditionalProperties);
-    }
-
-    /// <summary>
-    /// Verifies that when the agent response has AdditionalProperties, the returned AgentMessage.Metadata contains the converted values.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_WhenResponseHasAdditionalProperties_ReturnsAgentMessageWithMetadataAsync()
-    {
-        // Arrange
-        AdditionalPropertiesDictionary additionalProps = new()
-        {
-            ["responseKey1"] = "responseValue1",
-            ["responseKey2"] = 123
-        };
-        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Test response")])
-        {
-            AdditionalProperties = additionalProps
-        };
-        ITaskManager taskManager = CreateAgentMockWithResponse(response).Object.MapA2A();
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-
-        // Assert
-        AgentMessage agentMessage = Assert.IsType<AgentMessage>(a2aResponse);
-        Assert.NotNull(agentMessage.Metadata);
-        Assert.Equal(2, agentMessage.Metadata.Count);
-        Assert.True(agentMessage.Metadata.ContainsKey("responseKey1"));
-        Assert.True(agentMessage.Metadata.ContainsKey("responseKey2"));
-        Assert.Equal("responseValue1", agentMessage.Metadata["responseKey1"].GetString());
-        Assert.Equal(123, agentMessage.Metadata["responseKey2"].GetInt32());
-    }
-
-    /// <summary>
-    /// Verifies that when the agent response has null AdditionalProperties, the returned AgentMessage.Metadata is null.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_WhenResponseHasNullAdditionalProperties_ReturnsAgentMessageWithNullMetadataAsync()
-    {
-        // Arrange
-        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Test response")])
-        {
-            AdditionalProperties = null
-        };
-        ITaskManager taskManager = CreateAgentMockWithResponse(response).Object.MapA2A();
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-
-        // Assert
-        AgentMessage agentMessage = Assert.IsType<AgentMessage>(a2aResponse);
-        Assert.Null(agentMessage.Metadata);
-    }
-
-    /// <summary>
-    /// Verifies that when the agent response has empty AdditionalProperties, the returned AgentMessage.Metadata is null.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_WhenResponseHasEmptyAdditionalProperties_ReturnsAgentMessageWithNullMetadataAsync()
-    {
-        // Arrange
-        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Test response")])
-        {
-            AdditionalProperties = []
-        };
-        ITaskManager taskManager = CreateAgentMockWithResponse(response).Object.MapA2A();
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-
-        // Assert
-        AgentMessage agentMessage = Assert.IsType<AgentMessage>(a2aResponse);
-        Assert.Null(agentMessage.Metadata);
-    }
-
-    /// <summary>
-    /// Verifies that when runMode is Message, the result is always an AgentMessage even when
-    /// the agent would otherwise support background responses.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_MessageMode_AlwaysReturnsAgentMessageAsync()
-    {
-        // Arrange
-        AgentRunOptions? capturedOptions = null;
-        ITaskManager taskManager = CreateAgentMock(options => capturedOptions = options)
-            .Object.MapA2A(runMode: AgentRunMode.DisallowBackground);
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-
-        // Assert
-        Assert.IsType<AgentMessage>(a2aResponse);
-        Assert.NotNull(capturedOptions);
-        Assert.False(capturedOptions.AllowBackgroundResponses);
-    }
-
-    /// <summary>
-    /// Verifies that in BackgroundIfSupported mode when the agent completes immediately (no ContinuationToken),
-    /// the result is an AgentMessage because the response type is determined solely by ContinuationToken presence.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_BackgroundIfSupportedMode_WhenNoContinuationToken_ReturnsAgentMessageAsync()
-    {
-        // Arrange
-        AgentRunOptions? capturedOptions = null;
-        ITaskManager taskManager = CreateAgentMock(options => capturedOptions = options)
-            .Object.MapA2A(runMode: AgentRunMode.AllowBackgroundIfSupported);
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-
-        // Assert
-        Assert.IsType<AgentMessage>(a2aResponse);
-        Assert.NotNull(capturedOptions);
-        Assert.True(capturedOptions.AllowBackgroundResponses);
-    }
-
-    /// <summary>
-    /// Verifies that a custom Dynamic delegate returning false produces an AgentMessage
-    /// even when the agent completes immediately (no ContinuationToken).
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_DynamicMode_WithFalseCallback_ReturnsAgentMessageAsync()
-    {
-        // Arrange
-        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Quick reply")]);
-        ITaskManager taskManager = CreateAgentMockWithResponse(response)
-            .Object.MapA2A(runMode: AgentRunMode.AllowBackgroundWhen((_, _) => ValueTask.FromResult(false)));
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-
-        // Assert
-        Assert.IsType<AgentMessage>(a2aResponse);
-    }
-
-#pragma warning disable MEAI001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
-
-    /// <summary>
-    /// Verifies that when the agent returns a ContinuationToken, an AgentTask in Working state is returned.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_WhenResponseHasContinuationToken_ReturnsAgentTaskInWorkingStateAsync()
-    {
-        // Arrange
-        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Starting work...")])
-        {
-            ContinuationToken = CreateTestContinuationToken()
-        };
-        ITaskManager taskManager = CreateAgentMockWithResponse(response).Object.MapA2A();
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-
-        // Assert
-        AgentTask agentTask = Assert.IsType<AgentTask>(a2aResponse);
-        Assert.Equal(TaskState.Working, agentTask.Status.State);
-    }
-
-    /// <summary>
-    /// Verifies that when the agent returns a ContinuationToken, the returned task includes
-    /// intermediate messages from the initial response in its status message.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_WhenResponseHasContinuationToken_TaskStatusHasIntermediateMessageAsync()
-    {
-        // Arrange
-        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Starting work...")])
-        {
-            ContinuationToken = CreateTestContinuationToken()
-        };
-        ITaskManager taskManager = CreateAgentMockWithResponse(response).Object.MapA2A();
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-
-        // Assert
-        AgentTask agentTask = Assert.IsType<AgentTask>(a2aResponse);
-        Assert.NotNull(agentTask.Status.Message);
-        TextPart textPart = Assert.IsType<TextPart>(Assert.Single(agentTask.Status.Message.Parts));
-        Assert.Equal("Starting work...", textPart.Text);
-    }
-
-    /// <summary>
-    /// Verifies that when the agent returns a ContinuationToken, the continuation token
-    /// is serialized into the AgentTask.Metadata for persistence.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_WhenResponseHasContinuationToken_StoresTokenInTaskMetadataAsync()
-    {
-        // Arrange
-        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Starting work...")])
-        {
-            ContinuationToken = CreateTestContinuationToken()
-        };
-        ITaskManager taskManager = CreateAgentMockWithResponse(response).Object.MapA2A();
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-
-        // Assert
-        AgentTask agentTask = Assert.IsType<AgentTask>(a2aResponse);
-        Assert.NotNull(agentTask.Metadata);
-        Assert.True(agentTask.Metadata.ContainsKey("__a2a__continuationToken"));
-    }
-
-    /// <summary>
-    /// Verifies that when a task is created (Working or Completed), the original user message
-    /// is added to the task history, matching the A2A SDK's behavior when it creates tasks internally.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_WhenTaskIsCreated_OriginalMessageIsInHistoryAsync()
-    {
-        // Arrange
-        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Starting work...")])
-        {
-            ContinuationToken = CreateTestContinuationToken()
-        };
-        ITaskManager taskManager = CreateAgentMockWithResponse(response).Object.MapA2A();
-        AgentMessage originalMessage = new() { MessageId = "user-msg-1", Role = MessageRole.User, Parts = [new TextPart { Text = "Do something" }] };
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = originalMessage
-        });
-
-        // Assert
-        AgentTask agentTask = Assert.IsType<AgentTask>(a2aResponse);
-        Assert.NotNull(agentTask.History);
-        Assert.Contains(agentTask.History, m => m.MessageId == "user-msg-1" && m.Role == MessageRole.User);
-    }
-
-    /// <summary>
-    /// Verifies that in BackgroundIfSupported mode when the agent completes immediately (no ContinuationToken),
-    /// the returned AgentMessage preserves the original context ID.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_BackgroundIfSupportedMode_WhenNoContinuationToken_ReturnsAgentMessageWithContextIdAsync()
-    {
-        // Arrange
-        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Done!")]);
-        ITaskManager taskManager = CreateAgentMockWithResponse(response)
-            .Object.MapA2A(runMode: AgentRunMode.AllowBackgroundIfSupported);
-        AgentMessage originalMessage = new() { MessageId = "user-msg-2", ContextId = "ctx-123", Role = MessageRole.User, Parts = [new TextPart { Text = "Quick task" }] };
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = originalMessage
-        });
-
-        // Assert
-        AgentMessage agentMessage = Assert.IsType<AgentMessage>(a2aResponse);
-        Assert.Equal("ctx-123", agentMessage.ContextId);
-    }
-
-    /// <summary>
-    /// Verifies that when OnTaskUpdated is invoked on a task with a pending continuation token
-    /// and the agent returns a completed response (null ContinuationToken), the task is updated to Completed.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_OnTaskUpdated_WhenBackgroundOperationCompletes_TaskIsCompletedAsync()
-    {
-        // Arrange
-        int callCount = 0;
-        Mock<AIAgent> agentMock = CreateAgentMockWithSequentialResponses(
-            // First call: return response with ContinuationToken (long-running)
-            new AgentResponse([new ChatMessage(ChatRole.Assistant, "Starting...")])
-            {
-                ContinuationToken = CreateTestContinuationToken()
-            },
-            // Second call (via OnTaskUpdated): return completed response
-            new AgentResponse([new ChatMessage(ChatRole.Assistant, "Done!")]),
-            ref callCount);
-        ITaskManager taskManager = agentMock.Object.MapA2A();
-
-        // Act — trigger OnMessageReceived to create the task
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-        AgentTask agentTask = Assert.IsType<AgentTask>(a2aResponse);
-        Assert.Equal(TaskState.Working, agentTask.Status.State);
-
-        // Act — invoke OnTaskUpdated to check on the background operation
-        await InvokeOnTaskUpdatedAsync(taskManager, agentTask);
-
-        // Assert — task should now be completed
-        AgentTask? updatedTask = await taskManager.GetTaskAsync(new TaskQueryParams { Id = agentTask.Id }, CancellationToken.None);
-        Assert.NotNull(updatedTask);
-        Assert.Equal(TaskState.Completed, updatedTask.Status.State);
-        Assert.NotNull(updatedTask.Artifacts);
-        Artifact artifact = Assert.Single(updatedTask.Artifacts);
-        TextPart textPart = Assert.IsType<TextPart>(Assert.Single(artifact.Parts));
-        Assert.Equal("Done!", textPart.Text);
-    }
-
-    /// <summary>
-    /// Verifies that when OnTaskUpdated is invoked on a task with a pending continuation token
-    /// and the agent returns another ContinuationToken, the task stays in Working state.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_OnTaskUpdated_WhenBackgroundOperationStillWorking_TaskRemainsWorkingAsync()
-    {
-        // Arrange
-        int callCount = 0;
-        Mock<AIAgent> agentMock = CreateAgentMockWithSequentialResponses(
-            // First call: return response with ContinuationToken
-            new AgentResponse([new ChatMessage(ChatRole.Assistant, "Starting...")])
-            {
-                ContinuationToken = CreateTestContinuationToken()
-            },
-            // Second call (via OnTaskUpdated): still working, return another token
-            new AgentResponse([new ChatMessage(ChatRole.Assistant, "Still working...")])
-            {
-                ContinuationToken = CreateTestContinuationToken()
-            },
-            ref callCount);
-        ITaskManager taskManager = agentMock.Object.MapA2A();
-
-        // Act — trigger OnMessageReceived to create the task
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-        AgentTask agentTask = Assert.IsType<AgentTask>(a2aResponse);
-
-        // Act — invoke OnTaskUpdated; agent still working
-        await InvokeOnTaskUpdatedAsync(taskManager, agentTask);
-
-        // Assert — task should still be in Working state
-        AgentTask? updatedTask = await taskManager.GetTaskAsync(new TaskQueryParams { Id = agentTask.Id }, CancellationToken.None);
-        Assert.NotNull(updatedTask);
-        Assert.Equal(TaskState.Working, updatedTask.Status.State);
-    }
-
-    /// <summary>
-    /// Verifies the full lifecycle: agent starts background work, first poll returns still working,
-    /// second poll returns completed.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_OnTaskUpdated_MultiplePolls_EventuallyCompletesAsync()
-    {
-        // Arrange
-        int callCount = 0;
-        Mock<AIAgent> agentMock = CreateAgentMockWithCallCount(ref callCount, invocation =>
-        {
-            return invocation switch
-            {
-                // First call: start background work
-                1 => new AgentResponse([new ChatMessage(ChatRole.Assistant, "Starting...")])
-                {
-                    ContinuationToken = CreateTestContinuationToken()
-                },
-                // Second call: still working
-                2 => new AgentResponse([new ChatMessage(ChatRole.Assistant, "Still working...")])
-                {
-                    ContinuationToken = CreateTestContinuationToken()
-                },
-                // Third call: done
-                _ => new AgentResponse([new ChatMessage(ChatRole.Assistant, "All done!")])
-            };
-        });
-        ITaskManager taskManager = agentMock.Object.MapA2A();
-
-        // Act — create the task
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Do work" }] }
-        });
-        AgentTask agentTask = Assert.IsType<AgentTask>(a2aResponse);
-        Assert.Equal(TaskState.Working, agentTask.Status.State);
-
-        // Act — first poll: still working
-        AgentTask? currentTask = await taskManager.GetTaskAsync(new TaskQueryParams { Id = agentTask.Id }, CancellationToken.None);
-        Assert.NotNull(currentTask);
-        await InvokeOnTaskUpdatedAsync(taskManager, currentTask);
-        currentTask = await taskManager.GetTaskAsync(new TaskQueryParams { Id = agentTask.Id }, CancellationToken.None);
-        Assert.NotNull(currentTask);
-        Assert.Equal(TaskState.Working, currentTask.Status.State);
-
-        // Act — second poll: completed
-        await InvokeOnTaskUpdatedAsync(taskManager, currentTask);
-        currentTask = await taskManager.GetTaskAsync(new TaskQueryParams { Id = agentTask.Id }, CancellationToken.None);
-        Assert.NotNull(currentTask);
-        Assert.Equal(TaskState.Completed, currentTask.Status.State);
-
-        // Assert — final output as artifact
-        Assert.NotNull(currentTask.Artifacts);
-        Artifact artifact = Assert.Single(currentTask.Artifacts);
-        TextPart textPart = Assert.IsType<TextPart>(Assert.Single(artifact.Parts));
-        Assert.Equal("All done!", textPart.Text);
-    }
-
-    /// <summary>
-    /// Verifies that when the agent throws during a background operation poll,
-    /// the task is updated to Failed state.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_OnTaskUpdated_WhenAgentThrows_TaskIsFailedAsync()
-    {
-        // Arrange
-        int callCount = 0;
-        Mock<AIAgent> agentMock = CreateAgentMockWithCallCount(ref callCount, invocation =>
-        {
-            if (invocation == 1)
-            {
-                return new AgentResponse([new ChatMessage(ChatRole.Assistant, "Starting...")])
-                {
-                    ContinuationToken = CreateTestContinuationToken()
-                };
-            }
-
-            throw new InvalidOperationException("Agent failed");
-        });
-        ITaskManager taskManager = agentMock.Object.MapA2A();
-
-        // Act — create the task
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-        AgentTask agentTask = Assert.IsType<AgentTask>(a2aResponse);
-
-        // Act — poll the task; agent throws
-        await Assert.ThrowsAsync<InvalidOperationException>(() => InvokeOnTaskUpdatedAsync(taskManager, agentTask));
-
-        // Assert — task should be Failed
-        AgentTask? updatedTask = await taskManager.GetTaskAsync(new TaskQueryParams { Id = agentTask.Id }, CancellationToken.None);
-        Assert.NotNull(updatedTask);
-        Assert.Equal(TaskState.Failed, updatedTask.Status.State);
-    }
-
-    /// <summary>
-    /// Verifies that in Task mode with a ContinuationToken, the result is an AgentTask in Working state.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_TaskMode_WhenContinuationToken_ReturnsWorkingAgentTaskAsync()
-    {
-        // Arrange
-        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Working on it...")])
-        {
-            ContinuationToken = CreateTestContinuationToken()
-        };
-        ITaskManager taskManager = CreateAgentMockWithResponse(response)
-            .Object.MapA2A(runMode: AgentRunMode.AllowBackgroundIfSupported);
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-
-        // Assert
-        AgentTask agentTask = Assert.IsType<AgentTask>(a2aResponse);
-        Assert.Equal(TaskState.Working, agentTask.Status.State);
-        Assert.NotNull(agentTask.Metadata);
-        Assert.True(agentTask.Metadata.ContainsKey("__a2a__continuationToken"));
-    }
-
-    /// <summary>
-    /// Verifies that when the agent returns a ContinuationToken with no progress messages,
-    /// the task transitions to Working state with a null status message.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_WhenContinuationTokenWithNoMessages_TaskStatusHasNullMessageAsync()
-    {
-        // Arrange
-        AgentResponse response = new([])
-        {
-            ContinuationToken = CreateTestContinuationToken()
-        };
-        ITaskManager taskManager = CreateAgentMockWithResponse(response).Object.MapA2A();
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-
-        // Assert
-        AgentTask agentTask = Assert.IsType<AgentTask>(a2aResponse);
-        Assert.Equal(TaskState.Working, agentTask.Status.State);
-        Assert.Null(agentTask.Status.Message);
-    }
-
-    /// <summary>
-    /// Verifies that when OnTaskUpdated is invoked on a completed task with a follow-up message
-    /// and no continuation token in metadata, the task processes history and completes with a new artifact.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_OnTaskUpdated_WhenNoContinuationToken_ProcessesHistoryAndCompletesAsync()
-    {
-        // Arrange
-        int callCount = 0;
-        Mock<AIAgent> agentMock = CreateAgentMockWithCallCount(ref callCount, invocation =>
-        {
-            return invocation switch
-            {
-                // First call: create a task with ContinuationToken
-                1 => new AgentResponse([new ChatMessage(ChatRole.Assistant, "Starting...")])
-                {
-                    ContinuationToken = CreateTestContinuationToken()
-                },
-                // Second call (via OnTaskUpdated): complete the background operation
-                2 => new AgentResponse([new ChatMessage(ChatRole.Assistant, "Done!")]),
-                // Third call (follow-up via OnTaskUpdated): complete follow-up
-                _ => new AgentResponse([new ChatMessage(ChatRole.Assistant, "Follow-up done!")])
-            };
-        });
-        ITaskManager taskManager = agentMock.Object.MapA2A();
-
-        // Act — create a working task (with continuation token)
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-        AgentTask agentTask = Assert.IsType<AgentTask>(a2aResponse);
-
-        // Act — first OnTaskUpdated: completes the background operation
-        await InvokeOnTaskUpdatedAsync(taskManager, agentTask);
-        agentTask = (await taskManager.GetTaskAsync(new TaskQueryParams { Id = agentTask.Id }, CancellationToken.None))!;
-        Assert.Equal(TaskState.Completed, agentTask.Status.State);
-
-        // Simulate a follow-up message by adding it to history and re-submitting via OnTaskUpdated
-        agentTask.History ??= [];
-        agentTask.History.Add(new AgentMessage { MessageId = "follow-up", Role = MessageRole.User, Parts = [new TextPart { Text = "Follow up" }] });
-
-        // Act — invoke OnTaskUpdated without a continuation token in metadata
-        await InvokeOnTaskUpdatedAsync(taskManager, agentTask);
-
-        // Assert
-        AgentTask? updatedTask = await taskManager.GetTaskAsync(new TaskQueryParams { Id = agentTask.Id }, CancellationToken.None);
-        Assert.NotNull(updatedTask);
-        Assert.Equal(TaskState.Completed, updatedTask.Status.State);
-        Assert.NotNull(updatedTask.Artifacts);
-        Assert.Equal(2, updatedTask.Artifacts.Count);
-        Artifact artifact = updatedTask.Artifacts[1];
-        TextPart textPart = Assert.IsType<TextPart>(Assert.Single(artifact.Parts));
-        Assert.Equal("Follow-up done!", textPart.Text);
-    }
-
-    /// <summary>
-    /// Verifies that when a task is cancelled, the continuation token is removed from metadata.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_OnTaskCancelled_RemovesContinuationTokenFromMetadataAsync()
-    {
-        // Arrange
-        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Starting...")])
-        {
-            ContinuationToken = CreateTestContinuationToken()
-        };
-        ITaskManager taskManager = CreateAgentMockWithResponse(response).Object.MapA2A();
-
-        // Act — create a working task with a continuation token
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-        AgentTask agentTask = Assert.IsType<AgentTask>(a2aResponse);
-        Assert.NotNull(agentTask.Metadata);
-        Assert.True(agentTask.Metadata.ContainsKey("__a2a__continuationToken"));
-
-        // Act — cancel the task
-        await taskManager.CancelTaskAsync(new TaskIdParams { Id = agentTask.Id }, CancellationToken.None);
-
-        // Assert — continuation token should be removed from metadata
-        Assert.False(agentTask.Metadata.ContainsKey("__a2a__continuationToken"));
-    }
-
-    /// <summary>
-    /// Verifies that when the agent throws an OperationCanceledException during a poll,
-    /// it is re-thrown without marking the task as Failed.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_OnTaskUpdated_WhenOperationCancelled_DoesNotMarkFailedAsync()
-    {
-        // Arrange
-        int callCount = 0;
-        Mock<AIAgent> agentMock = CreateAgentMockWithCallCount(ref callCount, invocation =>
-        {
-            if (invocation == 1)
-            {
-                return new AgentResponse([new ChatMessage(ChatRole.Assistant, "Starting...")])
-                {
-                    ContinuationToken = CreateTestContinuationToken()
-                };
-            }
-
-            throw new OperationCanceledException("Cancelled");
-        });
-        ITaskManager taskManager = agentMock.Object.MapA2A();
-
-        // Act — create the task
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage { MessageId = "test-id", Role = MessageRole.User, Parts = [new TextPart { Text = "Hello" }] }
-        });
-        AgentTask agentTask = Assert.IsType<AgentTask>(a2aResponse);
-
-        // Act — poll the task; agent throws OperationCanceledException
-        await Assert.ThrowsAsync<OperationCanceledException>(() => InvokeOnTaskUpdatedAsync(taskManager, agentTask));
-
-        // Assert — task should still be Working, not Failed
-        AgentTask? updatedTask = await taskManager.GetTaskAsync(new TaskQueryParams { Id = agentTask.Id }, CancellationToken.None);
-        Assert.NotNull(updatedTask);
-        Assert.Equal(TaskState.Working, updatedTask.Status.State);
-    }
-
-    /// <summary>
-    /// Verifies that when the incoming message has a ContextId, it is used for the task
-    /// rather than generating a new one.
-    /// </summary>
-    [Fact]
-    public async Task MapA2A_WhenMessageHasContextId_UsesProvidedContextIdAsync()
-    {
-        // Arrange
-        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Reply")]);
-        ITaskManager taskManager = CreateAgentMockWithResponse(response).Object.MapA2A();
-
-        // Act
-        A2AResponse a2aResponse = await InvokeOnMessageReceivedAsync(taskManager, new MessageSendParams
-        {
-            Message = new AgentMessage
-            {
-                MessageId = "test-id",
-                ContextId = "my-context-123",
-                Role = MessageRole.User,
-                Parts = [new TextPart { Text = "Hello" }]
-            }
-        });
-
-        // Assert
-        AgentMessage agentMessage = Assert.IsType<AgentMessage>(a2aResponse);
-        Assert.Equal("my-context-123", agentMessage.ContextId);
-    }
-
-#pragma warning restore MEAI001
-
-    private static Mock<AIAgent> CreateAgentMock(Action<AgentRunOptions?> optionsCallback)
-    {
-        Mock<AIAgent> agentMock = new() { CallBase = true };
-        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
-        agentMock
-            .Protected()
-            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
-            .ReturnsAsync(new TestAgentSession());
-        agentMock
-            .Protected()
-            .Setup<Task<AgentResponse>>("RunCoreAsync",
-                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
-                ItExpr.IsAny<AgentSession?>(),
-                ItExpr.IsAny<AgentRunOptions?>(),
-                ItExpr.IsAny<CancellationToken>())
-            .Callback<IEnumerable<ChatMessage>, AgentSession?, AgentRunOptions?, CancellationToken>(
-                (_, _, options, _) => optionsCallback(options))
-            .ReturnsAsync(new AgentResponse([new ChatMessage(ChatRole.Assistant, "Test response")]));
-
-        return agentMock;
-    }
-
-    private static Mock<AIAgent> CreateAgentMockWithResponse(AgentResponse response)
-    {
-        Mock<AIAgent> agentMock = new() { CallBase = true };
-        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
-        agentMock
-            .Protected()
-            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
-            .ReturnsAsync(new TestAgentSession());
-        agentMock
-            .Protected()
-            .Setup<Task<AgentResponse>>("RunCoreAsync",
-                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
-                ItExpr.IsAny<AgentSession?>(),
-                ItExpr.IsAny<AgentRunOptions?>(),
-                ItExpr.IsAny<CancellationToken>())
-            .ReturnsAsync(response);
-
-        return agentMock;
-    }
-
-    private static async Task<A2AResponse> InvokeOnMessageReceivedAsync(ITaskManager taskManager, MessageSendParams messageSendParams)
-    {
-        Func<MessageSendParams, CancellationToken, Task<A2AResponse>>? handler = taskManager.OnMessageReceived;
-        Assert.NotNull(handler);
-        return await handler.Invoke(messageSendParams, CancellationToken.None);
-    }
-
-    private static async Task InvokeOnTaskUpdatedAsync(ITaskManager taskManager, AgentTask agentTask)
-    {
-        Func<AgentTask, CancellationToken, Task>? handler = taskManager.OnTaskUpdated;
-        Assert.NotNull(handler);
-        await handler.Invoke(agentTask, CancellationToken.None);
-    }
-
-#pragma warning disable MEAI001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
-    private static ResponseContinuationToken CreateTestContinuationToken()
-    {
-        return ResponseContinuationToken.FromBytes(new byte[] { 0x01, 0x02, 0x03 });
-    }
-#pragma warning restore MEAI001
-
-    private static Mock<AIAgent> CreateAgentMockWithSequentialResponses(
-        AgentResponse firstResponse,
-        AgentResponse secondResponse,
-        ref int callCount)
-    {
-        return CreateAgentMockWithCallCount(ref callCount, invocation =>
-            invocation == 1 ? firstResponse : secondResponse);
-    }
-
-    private static Mock<AIAgent> CreateAgentMockWithCallCount(
-        ref int callCount,
-        Func<int, AgentResponse> responseFactory)
-    {
-        // Use a StrongBox to allow the lambda to capture a mutable reference
-        StrongBox<int> callCountBox = new(callCount);
-
-        Mock<AIAgent> agentMock = new() { CallBase = true };
-        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
-        agentMock
-            .Protected()
-            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
-            .ReturnsAsync(new TestAgentSession());
-        agentMock
-            .Protected()
-            .Setup<Task<AgentResponse>>("RunCoreAsync",
-                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
-                ItExpr.IsAny<AgentSession?>(),
-                ItExpr.IsAny<AgentRunOptions?>(),
-                ItExpr.IsAny<CancellationToken>())
-            .ReturnsAsync(() =>
-            {
-                int currentCall = Interlocked.Increment(ref callCountBox.Value);
-                return responseFactory(currentCall);
-            });
-
-        return agentMock;
-    }
-
-    private sealed class TestAgentSession : AgentSession;
-}

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/AgentRunModeTests.cs

@@ -0,0 +1,163 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests;
+
+/// <summary>
+/// Unit tests for the <see cref="AgentRunMode"/> class.
+/// </summary>
+public sealed class AgentRunModeTests
+{
+    /// <summary>
+    /// Verifies that AllowBackgroundWhen throws ArgumentNullException for null delegate.
+    /// </summary>
+    [Fact]
+    public void AllowBackgroundWhen_NullDelegate_ThrowsArgumentNullException()
+    {
+        // Arrange & Act & Assert
+        Assert.Throws<ArgumentNullException>(() =>
+            AgentRunMode.AllowBackgroundWhen(null!));
+    }
+
+    /// <summary>
+    /// Verifies that DisallowBackground equals another DisallowBackground instance.
+    /// </summary>
+    [Fact]
+    public void Equals_DisallowBackground_AreEqual()
+    {
+        // Arrange
+        var mode1 = AgentRunMode.DisallowBackground;
+        var mode2 = AgentRunMode.DisallowBackground;
+
+        // Act & Assert
+        Assert.True(mode1.Equals(mode2));
+        Assert.True(mode1 == mode2);
+        Assert.False(mode1 != mode2);
+        Assert.Equal(mode1.GetHashCode(), mode2.GetHashCode());
+    }
+
+    /// <summary>
+    /// Verifies that AllowBackgroundIfSupported equals another AllowBackgroundIfSupported instance.
+    /// </summary>
+    [Fact]
+    public void Equals_AllowBackgroundIfSupported_AreEqual()
+    {
+        // Arrange
+        var mode1 = AgentRunMode.AllowBackgroundIfSupported;
+        var mode2 = AgentRunMode.AllowBackgroundIfSupported;
+
+        // Act & Assert
+        Assert.True(mode1.Equals(mode2));
+        Assert.True(mode1 == mode2);
+    }
+
+    /// <summary>
+    /// Verifies that DisallowBackground and AllowBackgroundIfSupported are not equal.
+    /// </summary>
+    [Fact]
+    public void Equals_DifferentModes_AreNotEqual()
+    {
+        // Arrange
+        var disallow = AgentRunMode.DisallowBackground;
+        var allow = AgentRunMode.AllowBackgroundIfSupported;
+
+        // Act & Assert
+        Assert.False(disallow.Equals(allow));
+        Assert.False(disallow == allow);
+        Assert.True(disallow != allow);
+    }
+
+    /// <summary>
+    /// Verifies that Equals returns false for null.
+    /// </summary>
+    [Fact]
+    public void Equals_Null_ReturnsFalse()
+    {
+        // Arrange
+        var mode = AgentRunMode.DisallowBackground;
+
+        // Act & Assert
+        Assert.False(mode.Equals(null));
+        Assert.False(mode.Equals((object?)null));
+        Assert.False(mode == null);
+        Assert.True(mode != null);
+    }
+
+    /// <summary>
+    /// Verifies that two null AgentRunMode values are equal.
+    /// </summary>
+    [Fact]
+    public void Equals_BothNull_AreEqual()
+    {
+        // Arrange
+        AgentRunMode? mode1 = null;
+        AgentRunMode? mode2 = null;
+
+        // Act & Assert
+        Assert.True(mode1 == mode2);
+        Assert.False(mode1 != mode2);
+    }
+
+    /// <summary>
+    /// Verifies that ToString returns expected values.
+    /// </summary>
+    [Fact]
+    public void ToString_ReturnsExpectedValues()
+    {
+        // Act & Assert
+        Assert.Equal("message", AgentRunMode.DisallowBackground.ToString());
+        Assert.Equal("task", AgentRunMode.AllowBackgroundIfSupported.ToString());
+        Assert.Equal("dynamic", AgentRunMode.AllowBackgroundWhen((_, _) => ValueTask.FromResult(true)).ToString());
+    }
+
+    /// <summary>
+    /// Verifies that Equals works correctly with object parameter.
+    /// </summary>
+    [Fact]
+    public void Equals_WithObjectParameter_WorksCorrectly()
+    {
+        // Arrange
+        var mode = AgentRunMode.DisallowBackground;
+
+        // Act & Assert
+        Assert.True(mode.Equals((object)AgentRunMode.DisallowBackground));
+        Assert.False(mode.Equals((object)AgentRunMode.AllowBackgroundIfSupported));
+        Assert.False(mode.Equals("not a run mode"));
+    }
+
+    /// <summary>
+    /// Verifies that two AllowBackgroundWhen instances with different delegates are not considered equal,
+    /// because equality includes delegate identity for dynamic modes.
+    /// </summary>
+    [Fact]
+    public void Equals_AllowBackgroundWhen_DifferentDelegates_AreNotEqual()
+    {
+        // Arrange
+        var mode1 = AgentRunMode.AllowBackgroundWhen((_, _) => ValueTask.FromResult(true));
+        var mode2 = AgentRunMode.AllowBackgroundWhen((_, _) => ValueTask.FromResult(false));
+
+        // Act & Assert
+        Assert.False(mode1.Equals(mode2));
+        Assert.True(mode1 != mode2);
+    }
+
+    /// <summary>
+    /// Verifies that two AllowBackgroundWhen instances with the same delegate are considered equal.
+    /// </summary>
+    [Fact]
+    public void Equals_AllowBackgroundWhen_SameDelegate_AreEqual()
+    {
+        // Arrange
+        static ValueTask<bool> CallbackAsync(A2ARunDecisionContext _, CancellationToken __) => ValueTask.FromResult(true);
+        var mode1 = AgentRunMode.AllowBackgroundWhen(CallbackAsync);
+        var mode2 = AgentRunMode.AllowBackgroundWhen(CallbackAsync);
+
+        // Act & Assert
+        Assert.True(mode1.Equals(mode2));
+        Assert.True(mode1 == mode2);
+        Assert.Equal(mode1.GetHashCode(), mode2.GetHashCode());
+    }
+}

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/Converters/MessageConverterTests.cs

@@ -1,5 +1,6 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+using System.Collections.Generic;
 using System.Linq;
 using A2A;
 using Microsoft.Agents.AI.Hosting.A2A.Converters;
@@ -10,66 +11,66 @@ namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests.Converters;
 public class MessageConverterTests
 {
     [Fact]
-    public void ToChatMessages_MessageSendParams_Null_ReturnsEmptyCollection()
+    public void ToChatMessages_SendMessageRequest_Null_ReturnsEmptyCollection()
     {
-        MessageSendParams? messageSendParams = null;
+        SendMessageRequest? sendMessageRequest = null;
 
-        var result = messageSendParams!.ToChatMessages();
+        var result = sendMessageRequest!.ToChatMessages();
 
         Assert.NotNull(result);
         Assert.Empty(result);
     }
 
     [Fact]
-    public void ToChatMessages_MessageSendParams_WithNullMessage_ReturnsEmptyCollection()
+    public void ToChatMessages_SendMessageRequest_WithNullMessage_ReturnsEmptyCollection()
     {
-        var messageSendParams = new MessageSendParams
+        var sendMessageRequest = new SendMessageRequest
         {
             Message = null!
         };
 
-        var result = messageSendParams.ToChatMessages();
+        var result = sendMessageRequest.ToChatMessages();
 
         Assert.NotNull(result);
         Assert.Empty(result);
     }
 
     [Fact]
-    public void ToChatMessages_MessageSendParams_WithMessageWithoutParts_ReturnsEmptyCollection()
+    public void ToChatMessages_SendMessageRequest_WithMessageWithoutParts_ReturnsEmptyCollection()
     {
-        var messageSendParams = new MessageSendParams
+        var sendMessageRequest = new SendMessageRequest
         {
-            Message = new AgentMessage
+            Message = new Message
             {
                 MessageId = "test-id",
-                Role = MessageRole.User,
+                Role = Role.User,
                 Parts = null!
             }
         };
 
-        var result = messageSendParams.ToChatMessages();
+        var result = sendMessageRequest.ToChatMessages();
 
         Assert.NotNull(result);
         Assert.Empty(result);
     }
 
     [Fact]
-    public void ToChatMessages_MessageSendParams_WithValidTextMessage_ReturnsCorrectChatMessage()
+    public void ToChatMessages_SendMessageRequest_WithValidTextMessage_ReturnsCorrectChatMessage()
     {
-        var messageSendParams = new MessageSendParams
+        var sendMessageRequest = new SendMessageRequest
         {
-            Message = new AgentMessage
+            Message = new Message
             {
                 MessageId = "test-id",
-                Role = MessageRole.User,
+                Role = Role.User,
                 Parts =
                 [
-                    new TextPart { Text = "Hello, world!" }
+                    new Part { Text = "Hello, world!" }
                 ]
             }
         };
 
-        var result = messageSendParams.ToChatMessages();
+        var result = sendMessageRequest.ToChatMessages();
 
         Assert.NotNull(result);
         Assert.Single(result);
@@ -82,4 +83,68 @@ public class MessageConverterTests
         var textContent = Assert.IsType<TextContent>(chatMessage.Contents.First());
         Assert.Equal("Hello, world!", textContent.Text);
     }
+
+    [Fact]
+    public void ToParts_NullList_ReturnsEmptyList()
+    {
+        // Arrange
+        IList<ChatMessage>? messages = null;
+
+        // Act
+        var result = messages!.ToParts();
+
+        // Assert
+        Assert.NotNull(result);
+        Assert.Empty(result);
+    }
+
+    [Fact]
+    public void ToParts_EmptyList_ReturnsEmptyList()
+    {
+        // Arrange
+        IList<ChatMessage> messages = [];
+
+        // Act
+        var result = messages.ToParts();
+
+        // Assert
+        Assert.NotNull(result);
+        Assert.Empty(result);
+    }
+
+    [Fact]
+    public void ToParts_WithTextContent_ReturnsTextPart()
+    {
+        // Arrange
+        IList<ChatMessage> messages =
+        [
+            new ChatMessage(ChatRole.Assistant, "Hello from the agent!")
+        ];
+
+        // Act
+        var result = messages.ToParts();
+
+        // Assert
+        Assert.Single(result);
+        Assert.Equal("Hello from the agent!", result[0].Text);
+    }
+
+    [Fact]
+    public void ToParts_WithMultipleMessages_ReturnsAllParts()
+    {
+        // Arrange
+        IList<ChatMessage> messages =
+        [
+            new ChatMessage(ChatRole.User, "First message"),
+            new ChatMessage(ChatRole.Assistant, "Second message")
+        ];
+
+        // Act
+        var result = messages.ToParts();
+
+        // Assert
+        Assert.Equal(2, result.Count);
+        Assert.Equal("First message", result[0].Text);
+        Assert.Equal("Second message", result[1].Text);
+    }
 }

dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/EndpointRouteA2ABuilderExtensionsTests.cs

@@ -1,479 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-
-using System;
-using A2A;
-using Microsoft.Agents.AI.Hosting.A2A.UnitTests.Internal;
-using Microsoft.AspNetCore.Builder;
-using Microsoft.Extensions.AI;
-using Microsoft.Extensions.DependencyInjection;
-
-namespace Microsoft.Agents.AI.Hosting.A2A.UnitTests;
-
-/// <summary>
-/// Tests for MicrosoftAgentAIHostingA2AEndpointRouteBuilderExtensions.MapA2A method.
-/// </summary>
-public sealed class EndpointRouteA2ABuilderExtensionsTests
-{
-    /// <summary>
-    /// Verifies that MapA2A throws ArgumentNullException for null endpoints.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAgentBuilder_NullEndpoints_ThrowsArgumentNullException()
-    {
-        // Arrange
-        AspNetCore.Routing.IEndpointRouteBuilder endpoints = null!;
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-
-        // Act & Assert
-        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
-            endpoints.MapA2A(agentBuilder, "/a2a"));
-
-        Assert.Equal("endpoints", exception.ParamName);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A throws ArgumentNullException for null agentBuilder.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAgentBuilder_NullAgentBuilder_ThrowsArgumentNullException()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-        IHostedAgentBuilder agentBuilder = null!;
-
-        // Act & Assert
-        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
-            app.MapA2A(agentBuilder, "/a2a"));
-
-        Assert.Equal("agentBuilder", exception.ParamName);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A with IHostedAgentBuilder correctly maps the agent with default task manager configuration.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAgentBuilder_DefaultConfiguration_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-
-        // Act & Assert - Should not throw
-        var result = app.MapA2A(agentBuilder, "/a2a");
-        Assert.NotNull(result);
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A with IHostedAgentBuilder and custom task manager configuration succeeds.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAgentBuilder_CustomTaskManagerConfiguration_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-
-        // Act & Assert - Should not throw
-        var result = app.MapA2A(agentBuilder, "/a2a", taskManager => { });
-        Assert.NotNull(result);
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A with IHostedAgentBuilder and agent card succeeds.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAgentBuilder_WithAgentCard_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-
-        var agentCard = new AgentCard
-        {
-            Name = "Test Agent",
-            Description = "A test agent for A2A communication"
-        };
-
-        // Act & Assert - Should not throw
-        var result = app.MapA2A(agentBuilder, "/a2a", agentCard);
-        Assert.NotNull(result);
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A with IHostedAgentBuilder, agent card, and custom task manager configuration succeeds.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAgentBuilder_WithAgentCardAndCustomConfiguration_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-
-        var agentCard = new AgentCard
-        {
-            Name = "Test Agent",
-            Description = "A test agent for A2A communication"
-        };
-
-        // Act & Assert - Should not throw
-        var result = app.MapA2A(agentBuilder, "/a2a", agentCard, taskManager => { });
-        Assert.NotNull(result);
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A throws ArgumentNullException for null endpoints when using string agent name.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAgentName_NullEndpoints_ThrowsArgumentNullException()
-    {
-        // Arrange
-        AspNetCore.Routing.IEndpointRouteBuilder endpoints = null!;
-
-        // Act & Assert
-        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
-            endpoints.MapA2A("agent", "/a2a"));
-
-        Assert.Equal("endpoints", exception.ParamName);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A with string agent name correctly maps the agent.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAgentName_DefaultConfiguration_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-
-        // Act & Assert - Should not throw
-        var result = app.MapA2A("agent", "/a2a");
-        Assert.NotNull(result);
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A with string agent name and custom task manager configuration succeeds.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAgentName_CustomTaskManagerConfiguration_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-
-        // Act & Assert - Should not throw
-        var result = app.MapA2A("agent", "/a2a", taskManager => { });
-        Assert.NotNull(result);
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A with string agent name and agent card succeeds.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAgentName_WithAgentCard_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-
-        var agentCard = new AgentCard
-        {
-            Name = "Test Agent",
-            Description = "A test agent for A2A communication"
-        };
-
-        // Act & Assert - Should not throw
-        var result = app.MapA2A("agent", "/a2a", agentCard);
-        Assert.NotNull(result);
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A with string agent name, agent card, and custom task manager configuration succeeds.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAgentName_WithAgentCardAndCustomConfiguration_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-
-        var agentCard = new AgentCard
-        {
-            Name = "Test Agent",
-            Description = "A test agent for A2A communication"
-        };
-
-        // Act & Assert - Should not throw
-        var result = app.MapA2A("agent", "/a2a", agentCard, taskManager => { });
-        Assert.NotNull(result);
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A throws ArgumentNullException for null endpoints when using AIAgent.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAIAgent_NullEndpoints_ThrowsArgumentNullException()
-    {
-        // Arrange
-        AspNetCore.Routing.IEndpointRouteBuilder endpoints = null!;
-
-        // Act & Assert
-        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
-            endpoints.MapA2A((AIAgent)null!, "/a2a"));
-
-        Assert.Equal("endpoints", exception.ParamName);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A with AIAgent correctly maps the agent.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAIAgent_DefaultConfiguration_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-        AIAgent agent = app.Services.GetRequiredKeyedService<AIAgent>("agent");
-
-        // Act & Assert - Should not throw
-        var result = app.MapA2A(agent, "/a2a");
-        Assert.NotNull(result);
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A with AIAgent and custom task manager configuration succeeds.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAIAgent_CustomTaskManagerConfiguration_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-        AIAgent agent = app.Services.GetRequiredKeyedService<AIAgent>("agent");
-
-        // Act & Assert - Should not throw
-        var result = app.MapA2A(agent, "/a2a", taskManager => { });
-        Assert.NotNull(result);
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A with AIAgent and agent card succeeds.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAIAgent_WithAgentCard_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-        AIAgent agent = app.Services.GetRequiredKeyedService<AIAgent>("agent");
-
-        var agentCard = new AgentCard
-        {
-            Name = "Test Agent",
-            Description = "A test agent for A2A communication"
-        };
-
-        // Act & Assert - Should not throw
-        var result = app.MapA2A(agent, "/a2a", agentCard);
-        Assert.NotNull(result);
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A with AIAgent, agent card, and custom task manager configuration succeeds.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAIAgent_WithAgentCardAndCustomConfiguration_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-        AIAgent agent = app.Services.GetRequiredKeyedService<AIAgent>("agent");
-
-        var agentCard = new AgentCard
-        {
-            Name = "Test Agent",
-            Description = "A test agent for A2A communication"
-        };
-
-        // Act & Assert - Should not throw
-        var result = app.MapA2A(agent, "/a2a", agentCard, taskManager => { });
-        Assert.NotNull(result);
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that MapA2A throws ArgumentNullException for null endpoints when using ITaskManager.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithTaskManager_NullEndpoints_ThrowsArgumentNullException()
-    {
-        // Arrange
-        AspNetCore.Routing.IEndpointRouteBuilder endpoints = null!;
-        ITaskManager taskManager = null!;
-
-        // Act & Assert
-        ArgumentNullException exception = Assert.Throws<ArgumentNullException>(() =>
-            endpoints.MapA2A(taskManager, "/a2a"));
-
-        Assert.Equal("endpoints", exception.ParamName);
-    }
-
-    /// <summary>
-    /// Verifies that multiple agents can be mapped to different paths.
-    /// </summary>
-    [Fact]
-    public void MapA2A_MultipleAgents_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        IHostedAgentBuilder agent1Builder = builder.AddAIAgent("agent1", "Instructions1", chatClientServiceKey: "chat-client");
-        IHostedAgentBuilder agent2Builder = builder.AddAIAgent("agent2", "Instructions2", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-
-        // Act & Assert - Should not throw
-        app.MapA2A(agent1Builder, "/a2a/agent1");
-        app.MapA2A(agent2Builder, "/a2a/agent2");
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that custom paths can be specified for A2A endpoints.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithCustomPath_AcceptsValidPath()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-
-        // Act & Assert - Should not throw
-        app.MapA2A(agentBuilder, "/custom/a2a/path");
-        Assert.NotNull(app);
-    }
-
-    /// <summary>
-    /// Verifies that task manager configuration callback is invoked correctly.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAgentBuilder_TaskManagerConfigurationCallbackInvoked()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-
-        bool configureCallbackInvoked = false;
-
-        // Act
-        app.MapA2A(agentBuilder, "/a2a", taskManager =>
-        {
-            configureCallbackInvoked = true;
-            Assert.NotNull(taskManager);
-        });
-
-        // Assert
-        Assert.True(configureCallbackInvoked);
-    }
-
-    /// <summary>
-    /// Verifies that agent card with all properties is accepted.
-    /// </summary>
-    [Fact]
-    public void MapA2A_WithAgentBuilder_FullAgentCard_Succeeds()
-    {
-        // Arrange
-        WebApplicationBuilder builder = WebApplication.CreateBuilder();
-        IChatClient mockChatClient = new DummyChatClient();
-        builder.Services.AddKeyedSingleton("chat-client", mockChatClient);
-        IHostedAgentBuilder agentBuilder = builder.AddAIAgent("agent", "Instructions", chatClientServiceKey: "chat-client");
-        builder.Services.AddLogging();
-        using WebApplication app = builder.Build();
-
-        var agentCard = new AgentCard
-        {
-            Name = "Test Agent",
-            Description = "A comprehensive test agent"
-        };
-
-        // Act & Assert - Should not throw
-        var result = app.MapA2A(agentBuilder, "/a2a", agentCard);
-        Assert.NotNull(result);
-    }
-}

python/CHANGELOG.md

@@ -7,6 +7,24 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.1.1] - 2026-04-23
+
+### Added
+- **agent-framework-core**: Add `expected_output` ground-truth support to `evaluate_workflow` for similarity evaluators ([#5234](https://github.com/microsoft/agent-framework/pull/5234))
+- **agent-framework-ag-ui**, **agent-framework-a2a**: Propagate `thread_id` and `forwarded_props` through AG-UI to A2A `context_id` ([#5383](https://github.com/microsoft/agent-framework/pull/5383))
+- **samples**: Add second approval-required tool (`set_stop_loss`) to `concurrent_builder_tool_approval` sample ([#4875](https://github.com/microsoft/agent-framework/pull/4875))
+
+### Changed
+- **agent-framework-foundry-hosting**: Correct Development Status classifier from Beta (4) to Alpha (3) to match the package's lifecycle stage ([#5387](https://github.com/microsoft/agent-framework/pull/5387))
+- **tests**: Add Python flaky test report workflow ([#5342](https://github.com/microsoft/agent-framework/pull/5342))
+
+### Fixed
+- **agent-framework-openai**: Fix OpenAI Responses streaming to propagate `created_at` from the final `response.completed` event ([#5382](https://github.com/microsoft/agent-framework/pull/5382))
+- **agent-framework-openai**: Fix `OpenAIEmbeddingClient` to use `AsyncOpenAI` for `/openai/v1` endpoints ([#5137](https://github.com/microsoft/agent-framework/pull/5137))
+- **agent-framework-openai**: Exclude null `file_id` from `input_image` payload to prevent schema 400 errors ([#5125](https://github.com/microsoft/agent-framework/pull/5125))
+- **agent-framework-foundry**: Reconcile Toolbox hosted-tool payloads with the Responses API ([#5414](https://github.com/microsoft/agent-framework/pull/5414))
+- **agent-framework-ag-ui**: Pass client `thread_id` as `session_id` when constructing `AgentSession` ([#5384](https://github.com/microsoft/agent-framework/pull/5384))
+
 ## [1.1.0] - 2026-04-21
 
 ### Added

python/packages/a2a/agent_framework_a2a/_agent.py

@@ -295,7 +295,10 @@ class A2AAgent(AgentTelemetryLayer, BaseAgent):
         else:
             if not normalized_messages:
                 raise ValueError("At least one message is required when starting a new task (no continuation_token).")
-            a2a_message = self._prepare_message_for_a2a(normalized_messages[-1])
+            a2a_message = self._prepare_message_for_a2a(
+                normalized_messages[-1],
+                context_id=session.service_session_id if session else None,
+            )
             a2a_stream = self.client.send_message(a2a_message)
 
         provider_session = session
@@ -584,7 +587,7 @@ class A2AAgent(AgentTelemetryLayer, BaseAgent):
             return AgentResponse.from_updates(updates)
         return AgentResponse(messages=[], response_id=task.id, raw_representation=task)
 
-    def _prepare_message_for_a2a(self, message: Message) -> A2AMessage:
+    def _prepare_message_for_a2a(self, message: Message, *, context_id: str | None = None) -> A2AMessage:
         """Prepare a Message for the A2A protocol.
 
         Transforms Agent Framework Message objects into A2A protocol Messages by:
@@ -593,6 +596,13 @@ class A2AAgent(AgentTelemetryLayer, BaseAgent):
         - Converting file references (URI/data/hosted_file) to FilePart objects
         - Preserving metadata and additional properties from the original message
         - Setting the role to 'user' as framework messages are treated as user input
+
+        Args:
+            message: The framework Message to convert.
+            context_id: Optional fallback context identifier (e.g. derived from
+                ``AgentSession.service_session_id``). When the *message* already
+                carries a ``context_id`` in its ``additional_properties`` that
+                value takes precedence; otherwise this fallback is used.
         """
         parts: list[A2APart] = []
         if not message.contents:
@@ -672,7 +682,7 @@ class A2AAgent(AgentTelemetryLayer, BaseAgent):
             role=A2ARole("user"),
             parts=parts,
             message_id=message.message_id or uuid.uuid4().hex,
-            context_id=message.additional_properties.get("context_id"),
+            context_id=message.additional_properties.get("context_id") or context_id,
             metadata=metadata,
         )
 

python/packages/a2a/pyproject.toml

@@ -4,7 +4,7 @@ description = "A2A integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "a2a-sdk>=0.3.5,<0.3.24",
 ]
 

python/packages/a2a/tests/test_a2a_agent.py

@@ -46,6 +46,7 @@ class MockA2AClient:
         self.responses: list[Any] = []
         self.resubscribe_responses: list[Any] = []
         self.get_task_response: Task | None = None
+        self.last_message: Any = None
 
     def add_message_response(self, message_id: str, text: str, role: str = "agent") -> None:
         """Add a mock Message response."""
@@ -111,6 +112,7 @@ class MockA2AClient:
 
     async def send_message(self, message: Any) -> AsyncIterator[Any]:
         """Mock send_message method that yields responses."""
+        self.last_message = message
         self.call_count += 1
 
         # All queued responses are delivered as a single streaming batch per call.
@@ -539,6 +541,37 @@ def test_prepare_message_for_a2a_forwards_context_id() -> None:
     assert result.metadata == {"trace_id": "trace-456"}
 
 
+def test_prepare_message_for_a2a_uses_fallback_context_id() -> None:
+    """Test that context_id kwarg is used when message has no context_id property."""
+
+    agent = A2AAgent(client=MagicMock(), http_client=None)
+
+    message = Message(
+        role="user",
+        contents=[Content.from_text(text="Hello")],
+    )
+
+    result = agent._prepare_message_for_a2a(message, context_id="session-ctx-1")
+
+    assert result.context_id == "session-ctx-1"
+
+
+def test_prepare_message_for_a2a_message_context_id_takes_precedence() -> None:
+    """Test that message.additional_properties context_id wins over the fallback."""
+
+    agent = A2AAgent(client=MagicMock(), http_client=None)
+
+    message = Message(
+        role="user",
+        contents=[Content.from_text(text="Hello")],
+        additional_properties={"context_id": "explicit-ctx"},
+    )
+
+    result = agent._prepare_message_for_a2a(message, context_id="session-ctx-1")
+
+    assert result.context_id == "explicit-ctx"
+
+
 def test_parse_contents_from_a2a_with_data_part() -> None:
     """Test conversion of A2A DataPart."""
 
@@ -868,6 +901,43 @@ async def test_poll_task_completed(a2a_agent: A2AAgent, mock_a2a_client: MockA2A
 # endregion
 
 
+# region Session context_id Integration Tests
+
+
+@mark.asyncio
+async def test_run_passes_session_service_session_id_as_context_id(mock_a2a_client: MockA2AClient) -> None:
+    """Test that run() wires session.service_session_id to the A2A message context_id."""
+    agent = A2AAgent(name="Test Agent", id="test-agent", client=mock_a2a_client, http_client=None)
+    mock_a2a_client.add_message_response("msg-ctx", "reply")
+
+    session = AgentSession(service_session_id="svc-session-42")
+    await agent.run("Hello", session=session)
+
+    assert mock_a2a_client.last_message is not None
+    assert mock_a2a_client.last_message.context_id == "svc-session-42"
+
+
+@mark.asyncio
+async def test_run_message_context_id_takes_precedence_over_session(mock_a2a_client: MockA2AClient) -> None:
+    """Test that an explicit context_id on the message wins over session.service_session_id."""
+    agent = A2AAgent(name="Test Agent", id="test-agent", client=mock_a2a_client, http_client=None)
+    mock_a2a_client.add_message_response("msg-ctx2", "reply")
+
+    session = AgentSession(service_session_id="svc-session-42")
+    message = Message(
+        role="user",
+        contents=[Content.from_text(text="Hello")],
+        additional_properties={"context_id": "explicit-ctx"},
+    )
+    await agent.run(messages=[message], session=session)
+
+    assert mock_a2a_client.last_message is not None
+    assert mock_a2a_client.last_message.context_id == "explicit-ctx"
+
+
+# endregion
+
+
 # region Context Provider Tests
 
 

python/packages/ag-ui/agent_framework_ag_ui/_agent_run.py

@@ -790,9 +790,9 @@ async def run_agent_stream(
     # Create session (with service session support)
     if config.use_service_session:
         supplied_thread_id = input_data.get("thread_id") or input_data.get("threadId")
-        session = AgentSession(service_session_id=supplied_thread_id)
+        session = AgentSession(session_id=thread_id, service_session_id=supplied_thread_id)
     else:
-        session = AgentSession()
+        session = AgentSession(session_id=thread_id)
 
     # Inject metadata for AG-UI orchestration (Feature #2: Azure-safe truncation)
     base_metadata: dict[str, Any] = {

python/packages/ag-ui/pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "agent-framework-ag-ui"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 description = "AG-UI protocol integration for Agent Framework"
 readme = "README.md"
 license-files = ["LICENSE"]
@@ -22,7 +22,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "ag-ui-protocol==0.1.13",
     "fastapi>=0.115.0,<0.133.1",
     "uvicorn[standard]>=0.30.0,<0.42.0"

python/packages/ag-ui/tests/ag_ui/conftest.py

@@ -183,6 +183,7 @@ class StubAgent(SupportsAgentRun):
         self.client = client or SimpleNamespace(function_invocation_configuration=None)
         self.messages_received: list[Any] = []
         self.tools_received: list[Any] | None = None
+        self.last_session: AgentSession | None = None
 
     @overload
     def run(
@@ -216,6 +217,7 @@ class StubAgent(SupportsAgentRun):
 
             async def _stream() -> AsyncIterator[AgentResponseUpdate]:
                 self.messages_received = [] if messages is None else list(messages)  # type: ignore[arg-type]
+                self.last_session = session
                 self.tools_received = kwargs.get("tools")
                 for update in self.updates:
                     yield update

python/packages/ag-ui/tests/ag_ui/test_run.py

@@ -1640,3 +1640,115 @@ class TestReasoningInSnapshot:
         # close: MsgEnd(block2) + End(block2)
         assert isinstance(close[0], ReasoningMessageEndEvent)
         assert close[0].message_id == "block2"
+
+
+async def test_session_id_matches_thread_id():
+    """Session created by run_agent_stream uses the client thread_id as session_id."""
+    from conftest import StubAgent
+
+    from agent_framework_ag_ui import AgentFrameworkAgent
+
+    stub = StubAgent()
+    agent = AgentFrameworkAgent(agent=stub)
+
+    payload = {
+        "thread_id": "my-thread-123",
+        "run_id": "run-1",
+        "messages": [{"role": "user", "content": "Hello"}],
+    }
+
+    _ = [event async for event in agent.run(payload)]
+
+    assert stub.last_session is not None
+    assert stub.last_session.session_id == "my-thread-123"
+
+
+async def test_session_id_matches_camel_case_thread_id():
+    """Session uses threadId (camelCase) as session_id when snake_case is absent."""
+    from conftest import StubAgent
+
+    from agent_framework_ag_ui import AgentFrameworkAgent
+
+    stub = StubAgent()
+    agent = AgentFrameworkAgent(agent=stub)
+
+    payload = {
+        "threadId": "camel-thread-456",
+        "run_id": "run-2",
+        "messages": [{"role": "user", "content": "Hello"}],
+    }
+
+    _ = [event async for event in agent.run(payload)]
+
+    assert stub.last_session is not None
+    assert stub.last_session.session_id == "camel-thread-456"
+
+
+async def test_session_id_matches_thread_id_with_service_session():
+    """Session uses thread_id as session_id even when use_service_session is enabled."""
+    from conftest import StubAgent
+
+    from agent_framework_ag_ui import AgentFrameworkAgent
+
+    stub = StubAgent()
+    agent = AgentFrameworkAgent(agent=stub, use_service_session=True)
+
+    payload = {
+        "thread_id": "service-thread-789",
+        "run_id": "run-3",
+        "messages": [{"role": "user", "content": "Hello"}],
+    }
+
+    _ = [event async for event in agent.run(payload)]
+
+    assert stub.last_session is not None
+    assert stub.last_session.session_id == "service-thread-789"
+    assert stub.last_session.service_session_id == "service-thread-789"
+
+
+async def test_session_id_generated_when_no_thread_id():
+    """Session gets a generated UUID as session_id when no thread_id is provided."""
+    import uuid
+
+    from conftest import StubAgent
+
+    from agent_framework_ag_ui import AgentFrameworkAgent
+
+    stub = StubAgent()
+    agent = AgentFrameworkAgent(agent=stub)
+
+    payload = {
+        "run_id": "run-4",
+        "messages": [{"role": "user", "content": "Hello"}],
+    }
+
+    _ = [event async for event in agent.run(payload)]
+
+    assert stub.last_session is not None
+    # Should be a valid UUID (auto-generated)
+    uuid.UUID(stub.last_session.session_id)
+
+
+async def test_service_session_no_thread_id_generates_uuid():
+    """With use_service_session=True and no thread_id, session_id is a UUID and service_session_id is None."""
+    import uuid
+
+    from conftest import StubAgent
+
+    from agent_framework_ag_ui import AgentFrameworkAgent
+
+    stub = StubAgent()
+    agent = AgentFrameworkAgent(agent=stub, use_service_session=True)
+
+    payload = {
+        "run_id": "run-5",
+        "messages": [{"role": "user", "content": "Hello"}],
+    }
+
+    _ = [event async for event in agent.run(payload)]
+
+    assert stub.last_session is not None
+    # session_id should be a valid auto-generated UUID
+    uuid.UUID(stub.last_session.session_id)
+    # service_session_id should be None since no thread_id was supplied
+    assert stub.last_session.service_session_id is None

python/packages/anthropic/pyproject.toml

@@ -4,7 +4,7 @@ description = "Anthropic integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "anthropic>=0.80.0,<0.80.1",
 ]
 

python/packages/azure-ai-search/pyproject.toml

@@ -4,7 +4,7 @@ description = "Azure AI Search integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "azure-search-documents>=11.7.0b2,<11.7.0b3",
 ]
 

python/packages/azure-cosmos/pyproject.toml

@@ -4,7 +4,7 @@ description = "Azure Cosmos DB history provider integration for Microsoft Agent
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "azure-cosmos>=4.3.0,<5",
 ]
 

python/packages/azurefunctions/pyproject.toml

@@ -4,7 +4,7 @@ description = "Azure Functions integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -22,7 +22,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "agent-framework-durabletask",
     "azure-functions>=1.24.0,<2",
     "azure-functions-durable>=1.3.1,<2",

python/packages/bedrock/pyproject.toml

@@ -4,7 +4,7 @@ description = "Amazon Bedrock integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "boto3>=1.35.0,<2.0.0",
     "botocore>=1.35.0,<2.0.0",
 ]

python/packages/chatkit/pyproject.toml

@@ -4,7 +4,7 @@ description = "OpenAI ChatKit integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -22,7 +22,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "openai-chatkit>=1.4.1,<2.0.0",
 ]
 

python/packages/claude/pyproject.toml

@@ -4,7 +4,7 @@ description = "Claude Agent SDK integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "claude-agent-sdk>=0.1.36,<0.1.49",
 ]
 

python/packages/copilotstudio/pyproject.toml

@@ -4,7 +4,7 @@ description = "Copilot Studio integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "microsoft-agents-copilotstudio-client>=0.3.1,<0.3.2",
 ]
 

python/packages/core/agent_framework/__init__.py

@@ -125,6 +125,7 @@ from ._telemetry import (
     prepend_agent_framework_to_user_agent,
 )
 from ._tools import (
+    SKIP_PARSING,
     FunctionInvocationConfiguration,
     FunctionInvocationLayer,
     FunctionTool,
@@ -258,6 +259,7 @@ __all__ = [
     "GROUP_INDEX_KEY",
     "GROUP_KIND_KEY",
     "GROUP_TOKEN_COUNT_KEY",
+    "SKIP_PARSING",
     "SUMMARIZED_BY_SUMMARY_ID_KEY",
     "SUMMARY_OF_GROUP_IDS_KEY",
     "SUMMARY_OF_MESSAGE_IDS_KEY",

python/packages/core/agent_framework/_tools.py

@@ -94,6 +94,33 @@ ApprovalMode: TypeAlias = Literal["always_require", "never_require"]
 ChatClientT = TypeVar("ChatClientT", bound="SupportsChatGetResponse[Any]")
 ResponseModelBoundT = TypeVar("ResponseModelBoundT", bound=BaseModel)
 
+
+class _SkipParsingSentinel:
+    """Sentinel signaling that :meth:`FunctionTool.invoke` should return the raw value.
+
+    When passed as ``result_parser`` to :class:`FunctionTool` (or the ``@tool`` decorator),
+    the default :meth:`FunctionTool.parse_result` is bypassed and the wrapped function's
+    return value is returned unchanged from :meth:`FunctionTool.invoke`. Callers may also
+    request the raw value on a per-call basis by passing ``skip_parsing=True`` to
+    :meth:`FunctionTool.invoke`.
+
+    Use the module-level ``SKIP_PARSING`` singleton — do not instantiate this class.
+    """
+
+    _instance: ClassVar[_SkipParsingSentinel | None] = None
+
+    def __new__(cls) -> _SkipParsingSentinel:
+        if cls._instance is None:
+            cls._instance = super().__new__(cls)
+        return cls._instance
+
+    def __repr__(self) -> str:
+        return "SKIP_PARSING"
+
+
+SKIP_PARSING: Final[_SkipParsingSentinel] = _SkipParsingSentinel()
+"""Sentinel for ``FunctionTool(result_parser=...)`` meaning "do not parse the result"."""
+
 # region Helpers
 
 
@@ -279,7 +306,7 @@ class FunctionTool(SerializationMixin):
         additional_properties: dict[str, Any] | None = None,
         func: Callable[..., Any] | None = None,
         input_model: type[BaseModel] | Mapping[str, Any] | None = None,
-        result_parser: Callable[[Any], str | list[Content]] | None = None,
+        result_parser: Callable[[Any], str | list[Content]] | _SkipParsingSentinel | None = None,
         **kwargs: Any,
     ) -> None:
         """Initialize the FunctionTool.
@@ -327,9 +354,11 @@ class FunctionTool(SerializationMixin):
             result_parser: An optional callable with signature ``Callable[[Any], str]`` that
                 overrides the default result parsing behavior. When provided, this callable
                 is used to convert the raw function return value to a string instead of the
-                built-in :meth:`parse_result` logic. Depending on your function, it may be
-                easiest to just do the serialization directly in the function body rather
-                than providing a custom ``result_parser``.
+                built-in :meth:`parse_result` logic. Pass the :data:`SKIP_PARSING` sentinel
+                instead of a callable to opt out of parsing entirely; in that case
+                :meth:`invoke` returns the wrapped function's raw return value. Depending
+                on your function, it may be easiest to just do the serialization directly
+                in the function body rather than providing a custom ``result_parser``.
             **kwargs: Additional keyword arguments.
         """
         # Core attributes (formerly from BaseTool)
@@ -508,31 +537,65 @@ class FunctionTool(SerializationMixin):
             self.invocation_exception_count += 1
             raise
 
+    @overload
     async def invoke(
         self,
         *,
         arguments: BaseModel | Mapping[str, Any] | None = None,
         context: FunctionInvocationContext | None = None,
         tool_call_id: str | None = None,
+        skip_parsing: Literal[True],
         **kwargs: Any,
-    ) -> list[Content]:
+    ) -> Any: ...
+
+    @overload
+    async def invoke(
+        self,
+        *,
+        arguments: BaseModel | Mapping[str, Any] | None = None,
+        context: FunctionInvocationContext | None = None,
+        tool_call_id: str | None = None,
+        skip_parsing: Literal[False] = False,
+        **kwargs: Any,
+    ) -> list[Content]: ...
+
+    async def invoke(
+        self,
+        *,
+        arguments: BaseModel | Mapping[str, Any] | None = None,
+        context: FunctionInvocationContext | None = None,
+        tool_call_id: str | None = None,
+        skip_parsing: bool = False,
+        **kwargs: Any,
+    ) -> list[Content] | Any:
         """Run the AI function with the provided arguments as a Pydantic model.
 
         The raw return value of the wrapped function is automatically parsed into a
         ``list[Content]`` using :meth:`parse_result` or the custom ``result_parser``
-        if one was provided.  Every result — text, rich media, or serialized objects —
-        is represented uniformly as Content items.
+        configured on the tool. Every result — text, rich media, or serialized
+        objects — is represented uniformly as Content items.
+
+        Parsing can be skipped in two ways: configure the tool with
+        ``result_parser=SKIP_PARSING`` to always skip parsing, or pass
+        ``skip_parsing=True`` per call. Either way the wrapped function's raw value
+        is returned. This is intended for callers (e.g. sandboxed runtimes) that
+        consume the value from Python directly and would otherwise undo the
+        ``Content`` wrapping.
 
         Keyword Args:
             arguments: A mapping or model instance containing the arguments for the function.
             context: Explicit function invocation context carrying runtime kwargs.
             tool_call_id: Optional tool call identifier used for telemetry and tracing.
+            skip_parsing: When ``True``, bypass parsing and return the wrapped function's
+                raw value instead of a ``list[Content]``. Defaults to ``False``.
             kwargs: Direct function argument values. When provided, every keyword
                 must match a declared tool parameter. Runtime data must be passed
                 via ``context``.
 
         Returns:
-            A list of Content items representing the tool output.
+            ``list[Content]`` by default. The raw function return value (``Any``) when
+            ``skip_parsing=True`` (or the tool was constructed with
+            ``result_parser=SKIP_PARSING``).
 
         Raises:
             TypeError: If arguments is not mapping-like or fails schema checks.
@@ -544,7 +607,9 @@ class FunctionTool(SerializationMixin):
         from ._types import Content
         from .observability import OBSERVABILITY_SETTINGS
 
-        parser = self.result_parser or FunctionTool.parse_result
+        configured_parser = self.result_parser
+        skip_parsing = skip_parsing or configured_parser is SKIP_PARSING
+        parser = configured_parser if callable(configured_parser) else FunctionTool.parse_result
 
         parameter_names = set(self.parameters().get("properties", {}).keys())
         direct_argument_kwargs = (
@@ -616,6 +681,10 @@ class FunctionTool(SerializationMixin):
             logger.debug(f"Function arguments: {observable_kwargs}")
             res = self.__call__(**call_kwargs)
             result = await res if inspect.isawaitable(res) else res
+            if skip_parsing:
+                logger.info(f"Function {self.name} succeeded.")
+                logger.debug(f"Function result: {type(result).__name__}")
+                return result
             try:
                 parsed = parser(result)
             except Exception:
@@ -671,6 +740,13 @@ class FunctionTool(SerializationMixin):
                 logger.error(f"Function failed. Error: {exception}")
                 raise
             else:
+                if skip_parsing:
+                    logger.info(f"Function {self.name} succeeded.")
+                    if OBSERVABILITY_SETTINGS.SENSITIVE_DATA_ENABLED:  # type: ignore[name-defined]
+                        result_str = str(result)
+                        span.set_attribute(OtelAttr.TOOL_RESULT, result_str)
+                        logger.debug(f"Function result: {result_str}")
+                    return result
                 try:
                     parsed = parser(result)
                 except Exception:
@@ -1067,7 +1143,7 @@ def tool(
     max_invocations: int | None = None,
     max_invocation_exceptions: int | None = None,
     additional_properties: dict[str, Any] | None = None,
-    result_parser: Callable[[Any], str | list[Content]] | None = None,
+    result_parser: Callable[[Any], str | list[Content]] | _SkipParsingSentinel | None = None,
 ) -> FunctionTool: ...
 
 
@@ -1083,7 +1159,7 @@ def tool(
     max_invocations: int | None = None,
     max_invocation_exceptions: int | None = None,
     additional_properties: dict[str, Any] | None = None,
-    result_parser: Callable[[Any], str | list[Content]] | None = None,
+    result_parser: Callable[[Any], str | list[Content]] | _SkipParsingSentinel | None = None,
 ) -> Callable[[Callable[..., Any]], FunctionTool]: ...
 
 
@@ -1098,7 +1174,7 @@ def tool(
     max_invocations: int | None = None,
     max_invocation_exceptions: int | None = None,
     additional_properties: dict[str, Any] | None = None,
-    result_parser: Callable[[Any], str | list[Content]] | None = None,
+    result_parser: Callable[[Any], str | list[Content]] | _SkipParsingSentinel | None = None,
 ) -> FunctionTool | Callable[[Callable[..., Any]], FunctionTool]:
     """Decorate a function to turn it into a FunctionTool that can be passed to models and executed automatically.
 

python/packages/core/pyproject.toml

@@ -4,7 +4,7 @@ description = "Microsoft Agent Framework for building AI Agents with Python. Thi
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.1.0"
+version = "1.1.1"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"

python/packages/core/tests/core/test_tools.py

@@ -8,6 +8,7 @@ from opentelemetry.sdk.trace.export.in_memory_span_exporter import InMemorySpanE
 from pydantic import BaseModel
 
 from agent_framework import (
+    SKIP_PARSING,
     Content,
     FunctionTool,
     tool,
@@ -1300,4 +1301,165 @@ def test_normalize_tools_flattens_mapping_like_toolbox_with_tools_attr() -> None
     assert normalized[1] is standalone
 
 
+# region SKIP_PARSING sentinel & skip_parsing
+
+
+async def test_invoke_skip_parsing_returns_native_value() -> None:
+    """invoke(skip_parsing=True) returns the wrapped function's raw value."""
+
+    @tool
+    def get_weather(city: str) -> dict[str, Any]:
+        """Get the weather."""
+        return {"city": city, "temperature_c": 21.5, "conditions": "partly cloudy"}
+
+    raw = await get_weather.invoke(arguments={"city": "Seattle"}, skip_parsing=True)
+
+    assert isinstance(raw, dict)
+    assert raw == {"city": "Seattle", "temperature_c": 21.5, "conditions": "partly cloudy"}
+
+
+async def test_invoke_skip_parsing_passes_through_custom_objects() -> None:
+    """skip_parsing must not call str()/repr() on the result."""
+
+    class Custom:  # noqa: B903
+        def __init__(self, value: int) -> None:
+            self.value = value
+
+    @tool
+    def make() -> Custom:
+        """Make a custom object."""
+        return Custom(42)
+
+    raw = await make.invoke(skip_parsing=True)
+
+    assert isinstance(raw, Custom)
+    assert raw.value == 42
+
+
+async def test_invoke_skip_parsing_awaits_async_functions() -> None:
+    @tool
+    async def slow(x: int) -> int:
+        """Async tool."""
+        return x * 2
+
+    raw = await slow.invoke(arguments={"x": 21}, skip_parsing=True)
+    assert raw == 42
+
+
+async def test_invoke_skip_parsing_bypasses_configured_result_parser() -> None:
+    """The tool's own result_parser is bypassed when skip_parsing=True is requested."""
+    parser_calls: list[Any] = []
+
+    def parser(value: Any) -> str:
+        parser_calls.append(value)
+        return "PARSED"
+
+    @tool(result_parser=parser)
+    def make_dict() -> dict[str, int]:
+        """Returns a dict."""
+        return {"a": 1}
+
+    raw = await make_dict.invoke(skip_parsing=True)
+    assert raw == {"a": 1}
+    assert parser_calls == []
+
+    # Sanity: omitting skip_parsing still applies the configured parser.
+    parsed = await make_dict.invoke()
+    assert parsed[0].type == "text"
+    assert parsed[0].text == "PARSED"
+
+
+async def test_constructor_skip_parsing_sentinel_returns_raw_by_default() -> None:
+    """Constructing a tool with result_parser=SKIP_PARSING makes invoke return the raw value."""
+
+    @tool(result_parser=SKIP_PARSING)
+    def make_dict() -> dict[str, int]:
+        """Returns a dict."""
+        return {"a": 1}
+
+    raw = await make_dict.invoke()
+    assert raw == {"a": 1}
+
+
+async def test_invoke_skip_parsing_validates_arguments() -> None:
+    """Argument validation is shared with the default path."""
+
+    @tool
+    def adder(x: int, y: int) -> int:
+        """Add."""
+        return x + y
+
+    with pytest.raises(TypeError):
+        await adder.invoke(arguments={"x": "not-an-int", "y": 1}, skip_parsing=True)
+
+
+async def test_invoke_skip_parsing_rejects_unexpected_runtime_kwargs() -> None:
+    @tool
+    async def echo(message: str) -> str:
+        """Echo."""
+        return message
+
+    with pytest.raises(TypeError, match="Unexpected keyword argument"):
+        await echo.invoke(arguments={"message": "hi"}, skip_parsing=True, api_token="secret")
+
+
+async def test_invoke_skip_parsing_raises_for_declaration_only_tool() -> None:
+    declared = FunctionTool(name="dummy", description="declaration only")
+
+    from agent_framework.exceptions import ToolException
+
+    with pytest.raises(ToolException):
+        await declared.invoke(arguments={}, skip_parsing=True)
+
+
+async def test_invoke_skip_parsing_records_telemetry(span_exporter: InMemorySpanExporter) -> None:
+    """skip_parsing participates in OTEL spans and records str(raw) as TOOL_RESULT."""
+
+    @tool(name="raw_tool", description="raw tool")
+    def returns_dict(x: int) -> dict[str, int]:
+        """Returns a dict."""
+        return {"value": x}
+
+    span_exporter.clear()
+    raw = await returns_dict.invoke(arguments={"x": 5}, tool_call_id="raw_call", skip_parsing=True)
+
+    assert raw == {"value": 5}
+    spans = span_exporter.get_finished_spans()
+    assert len(spans) == 1
+    span = spans[0]
+    assert span.attributes[OtelAttr.TOOL_NAME] == "raw_tool"
+    assert span.attributes[OtelAttr.TOOL_CALL_ID] == "raw_call"
+    assert span.attributes[OtelAttr.TOOL_RESULT] == "{'value': 5}"
+
+
+async def test_invoke_default_path_records_parsed_telemetry(
+    span_exporter: InMemorySpanExporter,
+) -> None:
+    """Regression: omitting skip_parsing still records the parsed result in telemetry."""
+
+    def parser(value: Any) -> str:
+        return f"parsed:{value}"
+
+    @tool(name="parsed_tool", description="parsed", result_parser=parser)
+    def returns_int() -> int:
+        """Returns an int."""
+        return 7
+
+    span_exporter.clear()
+    parsed = await returns_int.invoke(tool_call_id="parsed_call")
+
+    assert parsed[0].text == "parsed:7"
+    spans = span_exporter.get_finished_spans()
+    assert len(spans) == 1
+    assert spans[0].attributes[OtelAttr.TOOL_RESULT] == "parsed:7"
+
+
+def test_skip_parsing_is_singleton() -> None:
+    """SKIP_PARSING is a singleton; instantiation returns the same object."""
+    from agent_framework._tools import _SkipParsingSentinel
+
+    assert _SkipParsingSentinel() is SKIP_PARSING
+    assert repr(SKIP_PARSING) == "SKIP_PARSING"
+
+
 # endregion

python/packages/declarative/pyproject.toml

@@ -4,7 +4,7 @@ description = "Declarative specification support for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -22,7 +22,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "powerfx>=0.0.32,<0.0.35; python_version < '3.14'",
     "pyyaml>=6.0,<7.0",
 ]

python/packages/devui/pyproject.toml

@@ -4,7 +4,7 @@ description = "Debug UI for Microsoft Agent Framework with OpenAI-compatible API
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://github.com/microsoft/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
  dependencies = [
-     "agent-framework-core>=1.1.0,<2",
+     "agent-framework-core>=1.1.1,<2",
      "openai>=1.99.0,<3",
      "opentelemetry-sdk>=1.39.0,<2",
      "fastapi>=0.115.0,<0.133.1",

python/packages/durabletask/pyproject.toml

@@ -4,7 +4,7 @@ description = "Durable Task integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -22,7 +22,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "durabletask>=1.3.0,<2",
     "durabletask-azuremanaged>=1.3.0,<2",
     "python-dateutil>=2.8.0,<3",

python/packages/foundry/agent_framework_foundry/_chat_client.py

@@ -455,8 +455,18 @@ class RawFoundryChatClient(  # type: ignore[misc]
 
         Returns:
             An MCPTool configuration ready to pass to an Agent.
+
+        Raises:
+            ValueError: If neither ``url`` nor ``project_connection_id`` is supplied
+                — one is required by the Foundry Responses API.
         """
-        mcp = FoundryMCPTool(server_label=name.replace(" ", "_"), server_url=url or "", **kwargs)
+        if not url and not project_connection_id:
+            raise ValueError("MCP tool requires either 'url' or 'project_connection_id' to be specified.")
+
+        mcp_kwargs: dict[str, Any] = {"server_label": name.replace(" ", "_"), **kwargs}
+        if url:
+            mcp_kwargs["server_url"] = url
+        mcp = FoundryMCPTool(**mcp_kwargs)
 
         if description:
             mcp["server_description"] = description

python/packages/foundry/agent_framework_foundry/_tools.py

@@ -133,26 +133,55 @@ def select_toolbox_tools(
     return selected
 
 
+def _validate_hosted_tool_payload(sanitized: Mapping[str, Any]) -> None:
+    """Fail fast on hosted tool payloads that would always be rejected by the Responses API.
+
+    These mismatches are not injectable defaults — the caller must supply the
+    missing information — so surfacing a clear error here points at the toolbox
+    definition instead of letting the API return a generic 400.
+    """
+    tool_type = sanitized.get("type")
+    if tool_type == "file_search" and not sanitized.get("vector_store_ids"):
+        raise ValueError(
+            "'file_search' tool is missing required 'vector_store_ids'. "
+            "If this came from a Foundry toolbox, update the toolbox definition "
+            "to include at least one vector store ID."
+        )
+    if tool_type == "mcp" and not sanitized.get("server_url") and not sanitized.get("project_connection_id"):
+        raise ValueError(
+            "'mcp' tool is missing both 'server_url' and 'project_connection_id'. "
+            "If this came from a Foundry toolbox, update the toolbox definition "
+            "to include one of these."
+        )
+
+
 @experimental(feature_id=ExperimentalFeature.TOOLBOXES)
 def sanitize_foundry_response_tool(tool_item: Any) -> Any:
     """Return a Responses-API-safe tool payload for Foundry hosted tools.
 
-    Azure AI Projects toolbox reads can currently return hosted tool objects with
-    extra read-model decoration fields such as top-level ``name`` and
-    ``description``. Azure AI Foundry rejects at least ``name`` on Responses API
-    requests with:
+    Reconciles known mismatches between toolbox reads and the Responses API:
 
-    ``Unknown parameter: 'tools[0].name'``.
+    1. Toolbox reads can return hosted tool objects decorated with read-model
+       fields such as top-level ``name`` and ``description``. The Responses API
+       rejects at least ``name`` with ``Unknown parameter: 'tools[0].name'``.
+       These fields are stripped from non-function hosted tool payloads.
+    2. ``code_interpreter`` tools stored in a toolbox without a ``container``
+       field (the Azure SDK treats it as optional) are rejected by the Responses
+       API with ``Missing required parameter: 'tools[N].container'``. A default
+       ``{"type": "auto"}`` container is injected when absent.
+    3. Hosted tools that are structurally incomplete in ways that cannot be
+       defaulted (``file_search`` without ``vector_store_ids``, ``mcp`` without
+       either ``server_url`` or ``project_connection_id``) raise ``ValueError``
+       with a message that points at the toolbox definition.
 
-    We defensively strip these decoration fields for non-function hosted tools so
-    the round-trip
-    ``toolbox.tools -> Agent(..., tools=...) -> run()`` works, while the Azure
-    SDK/service behavior is corrected upstream.
+    These are workarounds until the toolbox/Responses proxy normalizes payloads
+    server-side.
     """
     if isinstance(tool_item, FoundryMCPTool):
         sanitized: dict[str, Any] = dict(cast("Mapping[str, Any]", tool_item))
         sanitized.pop("name", None)
         sanitized.pop("description", None)
+        _validate_hosted_tool_payload(sanitized)
         return sanitized
 
     if isinstance(tool_item, Mapping):
@@ -161,6 +190,9 @@ def sanitize_foundry_response_tool(tool_item: Any) -> Any:
             sanitized = dict(mapping)
             sanitized.pop("name", None)
             sanitized.pop("description", None)
+            if sanitized.get("type") == "code_interpreter" and "container" not in sanitized:
+                sanitized["container"] = {"type": "auto"}
+            _validate_hosted_tool_payload(sanitized)
             return sanitized
 
     return cast(Any, tool_item)

python/packages/foundry/pyproject.toml

@@ -4,7 +4,7 @@ description = "Microsoft Foundry integrations for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.1.0"
+version = "1.1.1"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "agent-framework-openai>=1.1.0,<2",
     "azure-ai-inference>=1.0.0b9,<1.0.0b10",
     "azure-ai-projects>=2.1.0,<3.0",

python/packages/foundry/tests/foundry/test_foundry_chat_client.py

@@ -607,6 +607,14 @@ def test_get_mcp_tool_with_project_connection_id() -> None:
     assert tool_config["project_connection_id"] == "conn-123"
     assert tool_config["allowed_tools"] == ["search_docs"]
     assert tool_config["server_label"] == "Docs_MCP"
+    # ``server_url`` should not be fabricated when only a project connection is supplied.
+    assert "server_url" not in tool_config
+
+
+def test_get_mcp_tool_requires_url_or_project_connection_id() -> None:
+    """Missing both ``url`` and ``project_connection_id`` is always invalid."""
+    with pytest.raises(ValueError, match="url.*project_connection_id"):
+        FoundryChatClient.get_mcp_tool(name="x")
 
 
 def test_prepare_tools_for_openai_strips_extraneous_name_from_foundry_mcp_tool() -> None:
@@ -655,6 +663,103 @@ def test_prepare_tools_for_openai_strips_read_model_fields_from_toolbox_code_int
     assert "description" not in prepared
 
 
+def test_prepare_tools_for_openai_injects_default_container_for_code_interpreter_dict() -> None:
+    """Toolbox-returned code_interpreter without a container must get a default injected.
+
+    The Azure SDK treats ``container`` as optional, but the Responses API rejects
+    ``code_interpreter`` entries without one. The sanitizer backfills ``{"type": "auto"}``.
+    """
+    project_client = MagicMock()
+    project_client.get_openai_client.return_value = _make_mock_openai_client()
+    client = FoundryChatClient(project_client=project_client, model="test-model")
+
+    tool = {
+        "type": "code_interpreter",
+        "name": "code_interpreter_t6bbtm",
+    }
+
+    response_tools = client._prepare_tools_for_openai([tool])
+
+    assert len(response_tools) == 1
+    prepared = response_tools[0]
+    assert prepared["type"] == "code_interpreter"
+    assert prepared["container"] == {"type": "auto"}
+    assert "name" not in prepared
+
+
+def test_prepare_tools_for_openai_injects_default_container_for_code_interpreter_sdk_instance() -> None:
+    """SDK ``CodeInterpreterTool`` instances without a container must also be backfilled.
+
+    Reproduces the toolbox creation path that calls
+    ``CodeInterpreterTool(name="code_interpreter")`` without a container.
+    """
+    from azure.ai.projects.models import CodeInterpreterTool
+
+    project_client = MagicMock()
+    project_client.get_openai_client.return_value = _make_mock_openai_client()
+    client = FoundryChatClient(project_client=project_client, model="test-model")
+
+    response_tools = client._prepare_tools_for_openai([CodeInterpreterTool(name="code_interpreter")])
+
+    assert len(response_tools) == 1
+    prepared = response_tools[0]
+    assert prepared["type"] == "code_interpreter"
+    assert prepared["container"] == {"type": "auto"}
+    assert "name" not in prepared
+
+
+def test_prepare_tools_for_openai_preserves_existing_code_interpreter_container() -> None:
+    """An already-populated container must not be overwritten by the sanitizer."""
+    project_client = MagicMock()
+    project_client.get_openai_client.return_value = _make_mock_openai_client()
+    client = FoundryChatClient(project_client=project_client, model="test-model")
+
+    explicit_container = {"file_ids": ["file_123"], "type": "auto"}
+    tool = {"type": "code_interpreter", "container": explicit_container}
+
+    response_tools = client._prepare_tools_for_openai([tool])
+
+    assert response_tools[0]["container"] == explicit_container
+
+
+def test_prepare_tools_for_openai_rejects_file_search_without_vector_store_ids() -> None:
+    """``file_search`` without ``vector_store_ids`` is always invalid — surface a clear error."""
+    project_client = MagicMock()
+    project_client.get_openai_client.return_value = _make_mock_openai_client()
+    client = FoundryChatClient(project_client=project_client, model="test-model")
+
+    with pytest.raises(ValueError, match="vector_store_ids"):
+        client._prepare_tools_for_openai([{"type": "file_search", "name": "fs"}])
+
+
+def test_prepare_tools_for_openai_rejects_mcp_without_server_destination() -> None:
+    """``mcp`` with neither ``server_url`` nor ``project_connection_id`` is always invalid."""
+    project_client = MagicMock()
+    project_client.get_openai_client.return_value = _make_mock_openai_client()
+    client = FoundryChatClient(project_client=project_client, model="test-model")
+
+    tool = FoundryMCPTool(server_label="orphan")
+
+    with pytest.raises(ValueError, match="server_url.*project_connection_id"):
+        client._prepare_tools_for_openai([tool])
+
+
+def test_prepare_tools_for_openai_accepts_mcp_with_only_project_connection_id() -> None:
+    """MCP tools backed by a Foundry connection (no ``server_url``) must still pass validation."""
+    project_client = MagicMock()
+    project_client.get_openai_client.return_value = _make_mock_openai_client()
+    client = FoundryChatClient(project_client=project_client, model="test-model")
+
+    tool = FoundryMCPTool(server_label="githubmcp")
+    tool["project_connection_id"] = "githubmcp"
+
+    response_tools = client._prepare_tools_for_openai([tool])
+
+    assert len(response_tools) == 1
+    assert response_tools[0]["project_connection_id"] == "githubmcp"
+    assert "server_url" not in response_tools[0]
+
+
 def test_prepare_tools_for_openai_strips_name_from_non_function_hosted_tool_dicts() -> None:
     """All non-function hosted tool payloads should drop top-level read-model names."""
     project_client = MagicMock()

python/packages/foundry_hosting/pyproject.toml

@@ -4,7 +4,7 @@ description = "Foundry Hosting integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0a260421"
+version = "1.0.0a260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -12,7 +12,7 @@ urls.release_notes = "https://github.com/microsoft/agent-framework/releases?q=ta
 urls.issues = "https://github.com/microsoft/agent-framework/issues"
 classifiers = [
   "License :: OSI Approved :: MIT License",
-  "Development Status :: 4 - Alpha",
+  "Development Status :: 3 - Alpha",
   "Intended Audience :: Developers",
   "Programming Language :: Python :: 3",
   "Programming Language :: Python :: 3.10",
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "azure-ai-agentserver-core==2.0.0b2",
     "azure-ai-agentserver-responses==1.0.0b4",
     "azure-ai-agentserver-invocations==1.0.0b2",

python/packages/foundry_local/pyproject.toml

@@ -4,7 +4,7 @@ description = "Foundry Local integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "agent-framework-openai>=1.1.0,<2",
     "foundry-local-sdk>=0.5.1,<0.5.2",
 ]

python/packages/gemini/pyproject.toml

@@ -4,7 +4,7 @@ description = "Google Gemini integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0a260421"
+version = "1.0.0a260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -24,7 +24,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2.0",
+    "agent-framework-core>=1.1.1,<2.0",
     "google-genai>=1.0.0,<2.0.0",
 ]
 

python/packages/github_copilot/pyproject.toml

@@ -4,7 +4,7 @@ description = "GitHub Copilot integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "github-copilot-sdk>=0.2.1,<=0.2.1; python_version >= '3.11'",
 ]
 

python/packages/hyperlight/README.md

@@ -130,3 +130,9 @@ codeact = HyperlightCodeActProvider(
 - `allowed_domains` accepts a single string target such as `"github.com"` to
   allow all backend-supported methods, an explicit `(target, method_or_methods)`
   tuple such as `("github.com", "GET")`, or an `AllowedDomain` named tuple.
+- Tools registered with the sandbox return their native Python value
+  (`dict`, `list`, primitives, or custom objects) directly to the guest via the
+  Hyperlight FFI. Any `result_parser` configured on a `FunctionTool` is
+  intended for LLM-facing consumers and does not run on the sandbox path —
+  apply formatting inside the tool function itself if you need it for
+  in-sandbox consumers.

python/packages/hyperlight/agent_framework_hyperlight/_execute_code_tool.py

@@ -2,42 +2,45 @@
 
 from __future__ import annotations
 
-import ast
 import asyncio
-import copy
 import mimetypes
 import shutil
 import threading
 import time
 from collections.abc import Callable, Sequence
-from dataclasses import dataclass
+from concurrent.futures import Future, ThreadPoolExecutor
+from contextlib import suppress
+from copy import copy
+from dataclasses import dataclass, field
 from pathlib import Path, PurePosixPath
 from tempfile import TemporaryDirectory
-from typing import Annotated, Any, Protocol, TypeGuard, cast
+from typing import Any, Protocol, TypeGuard, TypeVar, cast
 from urllib.parse import urlparse
 
 from agent_framework import Content, FunctionTool
 from agent_framework._tools import ApprovalMode, normalize_tools
-from pydantic import BaseModel, Field
 
 from ._instructions import build_codeact_instructions, build_execute_code_description
 from ._types import AllowedDomain, AllowedDomainInput, FileMount, FileMountHostPath, FileMountInput
 
 DEFAULT_HYPERLIGHT_BACKEND = "wasm"
 DEFAULT_HYPERLIGHT_MODULE = "python_guest.path"
-EXECUTE_CODE_INPUT_DESCRIPTION = "Python code to execute in an isolated Hyperlight sandbox."
+EXECUTE_CODE_TOOL_DESCRIPTION = "Execute Python in an isolated Hyperlight sandbox."
 OUTPUT_FILE_RETRY_ATTEMPTS = 10
 OUTPUT_FILE_RETRY_DELAY_SECONDS = 0.1
 
-
-class _ExecuteCodeInput(BaseModel):
-    code: Annotated[str, Field(description=EXECUTE_CODE_INPUT_DESCRIPTION)]
-
-
-@dataclass(frozen=True, slots=True)
-class _StoredFileMount:
-    host_path: Path
-    mount_path: str
+EXECUTE_CODE_INPUT_SCHEMA: dict[str, Any] = {
+    "type": "object",
+    "title": "_ExecuteCodeInput",
+    "properties": {
+        "code": {
+            "type": "string",
+            "title": "Code",
+            "description": "Python code to execute in an isolated Hyperlight sandbox.",
+        },
+    },
+    "required": ["code"],
+}
 
 
 @dataclass(frozen=True, slots=True)
@@ -85,13 +88,43 @@ class SandboxRuntime(Protocol):
     def execute(self, *, config: _RunConfig, code: str) -> list[Content]: ...
 
 
+_T = TypeVar("_T")
+
+
+class _SandboxWorker:
+    """Single-threaded executor that confines all sandbox operations to one OS thread.
+
+    The Hyperlight ``WasmSandbox`` is declared ``unsendable`` in PyO3, meaning it can only be
+    accessed from the OS thread that created it; touching it from any other thread triggers a
+    Rust panic that cannot be caught from Python. Every cached :class:`_SandboxEntry` therefore
+    owns its own ``_SandboxWorker``, and *all* lifecycle and execution calls against the
+    underlying sandbox object must be routed through :meth:`submit`/:meth:`run`.
+    """
+
+    __slots__ = ("_executor",)
+
+    def __init__(self, *, name: str = "hl-sandbox") -> None:
+        self._executor = ThreadPoolExecutor(max_workers=1, thread_name_prefix=name)
+
+    def submit(self, fn: Callable[..., _T], /, *args: Any, **kwargs: Any) -> Future[_T]:
+        return self._executor.submit(fn, *args, **kwargs)
+
+    def run(self, fn: Callable[..., _T], /, *args: Any, **kwargs: Any) -> _T:
+        return self._executor.submit(fn, *args, **kwargs).result()
+
+    def shutdown(self) -> None:
+        # Do not block on shutdown; stop accepting new tasks, but allow the currently running
+        # task and any already-queued tasks to finish before the worker thread exits.
+        self._executor.shutdown(wait=False, cancel_futures=False)
+
+
 @dataclass
 class _SandboxEntry:
     sandbox: Any
     snapshot: Any
     input_dir: TemporaryDirectory[str] | None
     output_dir: TemporaryDirectory[str] | None
-    lock: threading.RLock
+    worker: _SandboxWorker = field(default_factory=_SandboxWorker)
 
 
 def _load_sandbox_class() -> type[Any]:
@@ -106,10 +139,6 @@ def _load_sandbox_class() -> type[Any]:
     return Sandbox
 
 
-def _passthrough_result_parser(result: Any) -> str:
-    return repr(result)
-
-
 def _collect_tools(*tool_groups: Any) -> list[FunctionTool]:
     tools_by_name: dict[str, FunctionTool] = {}
 
@@ -166,7 +195,7 @@ def _is_file_mount_pair(value: Any) -> TypeGuard[FileMount | tuple[FileMountHost
     return isinstance(host_path, (str, Path)) and isinstance(mount_path, str)
 
 
-def _normalize_file_mount_input(file_mount: FileMountInput) -> _StoredFileMount:
+def _normalize_file_mount_input(file_mount: FileMountInput) -> FileMount:
     host_path: FileMountHostPath
     mount_path: str
     if isinstance(file_mount, str):
@@ -176,7 +205,7 @@ def _normalize_file_mount_input(file_mount: FileMountInput) -> _StoredFileMount:
         host_path = file_mount[0]
         mount_path = file_mount[1]
 
-    return _StoredFileMount(
+    return FileMount(
         host_path=_resolve_existing_path(host_path),
         mount_path=_normalize_mount_path(mount_path),
     )
@@ -445,18 +474,13 @@ def _build_execution_contents(
 
 
 def _make_sandbox_callback(tool_obj: FunctionTool) -> Callable[..., Any]:
-    sandbox_tool = copy.copy(tool_obj)
-    # Auto-assign a passthrough parser so the raw return value round-trips through
-    # `ast.literal_eval` in the sandbox callback below. User-supplied parsers are
-    # left in place so callers can customize how results are exposed to the guest.
-    if sandbox_tool.result_parser is None:
-        sandbox_tool.result_parser = _passthrough_result_parser
+    sandbox_tool = copy(tool_obj)
 
     def _callback(**kwargs: Any) -> Any:
-        async def _invoke() -> list[Content]:
-            return await sandbox_tool.invoke(arguments=kwargs)
+        async def _invoke() -> Any:
+            return await sandbox_tool.invoke(arguments=kwargs, skip_parsing=True)
 
-        # FunctionTool.invoke() is always async. The real Hyperlight backend invokes
+        # FunctionTool.invoke() is async. The real Hyperlight backend invokes
         # registered callbacks synchronously via FFI, so this must be a sync function.
         # We run the async call on a dedicated thread to avoid conflicts with any
         # event loop that may be running on the current thread.
@@ -474,22 +498,11 @@ def _make_sandbox_callback(tool_obj: FunctionTool) -> Callable[..., Any]:
         worker.join()
         if error_box:
             raise error_box[0]
-        contents: list[Content] = result_box[0]
-
-        values: list[Any] = []
-        for content in contents:
-            if content.type == "text" and content.text is not None:
-                try:
-                    values.append(ast.literal_eval(content.text))
-                except (SyntaxError, ValueError):
-                    values.append(content.text)
-                continue
-
-            values.append(content.to_dict())
-
-        if len(values) == 1:
-            return values[0]
-        return values
+        # Return the raw value. The Hyperlight FFI marshals primitives (dict, list,
+        # str, int, float, bool, None) natively into the guest, and falls back to
+        # repr()/str() for unsupported types — so the guest receives real Python
+        # objects without a lossy host-side serialization round-trip.
+        return result_box[0]
 
     return _callback
 
@@ -509,7 +522,7 @@ def _clear_directory(output_dir: TemporaryDirectory[str] | None) -> None:
             pass
 
 
-class _SandboxRegistry:
+class _SandboxRegistry(SandboxRuntime):
     def __init__(self) -> None:
         self._entries: dict[tuple[Any, ...], _SandboxEntry] = {}
         self._entries_lock = threading.RLock()
@@ -517,28 +530,54 @@ class _SandboxRegistry:
     def execute(self, *, config: _RunConfig, code: str) -> list[Content]:
         """Execute code in a cached sandbox matching the given config.
 
-        Entries are keyed by ``config.cache_key()``. Concurrent calls with the same
-        key are serialized by the entry lock so they never race, but they share the
-        same sandbox instance. For true parallel execution, use distinct provider
-        instances or configs that produce different cache keys.
+        Entries are keyed by ``config.cache_key()``. All operations against the underlying
+        sandbox object are routed through the entry's dedicated single-threaded worker, which
+        both serializes concurrent callers and satisfies the PyO3 ``unsendable`` invariant
+        that the sandbox can only be touched from the thread that created it.
         """
+        entry = self._get_or_create_entry(config)
+        return entry.worker.run(self._run_on_worker, entry, code)
+
+    @staticmethod
+    def _run_on_worker(entry: _SandboxEntry, code: str) -> list[Content]:
+        entry.sandbox.restore(entry.snapshot)
+        _clear_directory(entry.output_dir)
+        result = entry.sandbox.run(code=code)
+        return _build_execution_contents(
+            result=result,
+            sandbox=entry.sandbox,
+            output_dir=entry.output_dir,
+            code=code,
+        )
+
+    def _get_or_create_entry(self, config: _RunConfig) -> _SandboxEntry:
         cache_key = config.cache_key()
         with self._entries_lock:
             entry = self._entries.get(cache_key)
             if entry is None:
                 entry = self._create_entry(config)
                 self._entries[cache_key] = entry
+            return entry
 
-        with entry.lock:
-            entry.sandbox.restore(entry.snapshot)
-            _clear_directory(entry.output_dir)
-            result = entry.sandbox.run(code=code)
-            return _build_execution_contents(
-                result=result,
-                sandbox=entry.sandbox,
-                output_dir=entry.output_dir,
-                code=code,
-            )
+    def close(self) -> None:
+        """Shut down all per-entry worker threads and release per-entry resources.
+
+        Safe to call multiple times. Runs any sandbox close hook on the entry's
+        own worker thread to honor the PyO3 ``unsendable`` invariant.
+        """
+        with self._entries_lock:
+            entries = list(self._entries.values())
+            self._entries.clear()
+        for entry in entries:
+            close_hook = getattr(entry.sandbox, "close", None) or getattr(entry.sandbox, "shutdown", None)
+            if callable(close_hook):
+                with suppress(Exception):
+                    entry.worker.run(close_hook)
+            entry.worker.shutdown()
+            for tmp_dir in (entry.input_dir, entry.output_dir):
+                if tmp_dir is not None:
+                    with suppress(Exception):
+                        tmp_dir.cleanup()
 
     def _create_entry(self, config: _RunConfig) -> _SandboxEntry:
         input_dir_handle = TemporaryDirectory() if config.filesystem_enabled else None
@@ -578,26 +617,37 @@ class _SandboxRegistry:
                         methods=list(allowed_domain.methods) if allowed_domain.methods is not None else None,
                     )
 
-        sandbox = _create_sandbox()
-        _configure_sandbox(sandbox=sandbox, expand_missing_scheme=False)
+        worker = _SandboxWorker()
+
+        def _build_sandbox() -> tuple[Any, Any]:
+            sandbox = _create_sandbox()
+            _configure_sandbox(sandbox=sandbox, expand_missing_scheme=False)
+
+            try:
+                sandbox.run("None")
+            except RuntimeError as exc:
+                if not _should_retry_allowed_domain_registration(error=exc, allowed_domains=config.allowed_domains):
+                    raise
+
+                sandbox = _create_sandbox()
+                _configure_sandbox(sandbox=sandbox, expand_missing_scheme=True)
+                sandbox.run("None")
+
+            snapshot = sandbox.snapshot()
+            return sandbox, snapshot
 
         try:
-            sandbox.run("None")
-        except RuntimeError as exc:
-            if not _should_retry_allowed_domain_registration(error=exc, allowed_domains=config.allowed_domains):
-                raise
+            sandbox, snapshot = worker.run(_build_sandbox)
+        except BaseException:
+            worker.shutdown()
+            raise
 
-            sandbox = _create_sandbox()
-            _configure_sandbox(sandbox=sandbox, expand_missing_scheme=True)
-            sandbox.run("None")
-
-        snapshot = sandbox.snapshot()
         return _SandboxEntry(
             sandbox=sandbox,
             snapshot=snapshot,
             input_dir=input_dir_handle,
             output_dir=output_dir_handle,
-            lock=threading.RLock(),
+            worker=worker,
         )
 
 
@@ -619,10 +669,10 @@ class HyperlightExecuteCodeTool(FunctionTool):
     ) -> None:
         super().__init__(
             name="execute_code",
-            description=EXECUTE_CODE_INPUT_DESCRIPTION,
+            description=EXECUTE_CODE_TOOL_DESCRIPTION,
             approval_mode="never_require",
             func=self._run_code,
-            input_model=_ExecuteCodeInput,
+            input_model=EXECUTE_CODE_INPUT_SCHEMA,
         )
         self._state_lock = threading.RLock()
         self._registry = _registry or _SandboxRegistry()
@@ -632,7 +682,7 @@ class HyperlightExecuteCodeTool(FunctionTool):
         self._module: str | None = module
         self._module_path: str | None = module_path
         self._managed_tools: list[FunctionTool] = []
-        self._file_mounts: dict[str, _StoredFileMount] = {}
+        self._file_mounts: dict[str, FileMount] = {}
         self._allowed_domains: dict[str, AllowedDomain] = {}
 
         if tools is not None:
@@ -648,7 +698,7 @@ class HyperlightExecuteCodeTool(FunctionTool):
     def description(self) -> str:
         state_lock = getattr(self, "_state_lock", None)
         if state_lock is None:
-            return str(self.__dict__.get("description", EXECUTE_CODE_INPUT_DESCRIPTION))
+            return str(self.__dict__.get("description", EXECUTE_CODE_TOOL_DESCRIPTION))
 
         with state_lock:
             allowed_domains = sorted(self._allowed_domains.values(), key=lambda value: value.target)
@@ -841,9 +891,9 @@ class HyperlightExecuteCodeTool(FunctionTool):
         workspace_signature = _path_tree_signature(workspace_root) if workspace_root is not None else ()
         normalized_mounts = tuple(
             _NormalizedFileMount(
-                host_path=mount.host_path,
+                host_path=Path(mount.host_path),
                 mount_path=mount.mount_path,
-                path_signature=_path_tree_signature(mount.host_path),
+                path_signature=_path_tree_signature(Path(mount.host_path)),
             )
             for mount in stored_mounts
         )

python/packages/hyperlight/pyproject.toml

@@ -4,7 +4,7 @@ description = "Hyperlight CodeAct integrations for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0a260421"
+version = "1.0.0a260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -22,7 +22,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "hyperlight-sandbox>=0.3.0,<0.4",
     "hyperlight-sandbox-backend-wasm>=0.3.0,<0.4 ; ((sys_platform == 'linux' and platform_machine == 'x86_64') or (sys_platform == 'win32' and platform_machine == 'AMD64')) and python_version < '3.14'",
     "hyperlight-sandbox-python-guest>=0.3.0,<0.4",

python/packages/hyperlight/tests/hyperlight/test_hyperlight_codeact.py

@@ -937,3 +937,191 @@ async def test_run_code_does_not_block_event_loop() -> None:
 
     assert concurrent_ran, "Event loop was blocked during sandbox execution"
     assert result[0].type == "text"
+
+
+class _ThreadAffinityFakeSandbox(_FakeSandbox):
+    """Fake sandbox that records the OS thread of every method invocation.
+
+    Mirrors the PyO3 ``unsendable`` invariant of ``hyperlight_sandbox.WasmSandbox``:
+    if ``__init__``, ``register_tool``, ``allow_domain``, ``run``, ``snapshot`` or ``restore``
+    are ever called from more than one thread for a given instance, the test fails.
+    """
+
+    affinity_failures: list[str] = []
+
+    def __init__(self, **kwargs: Any) -> None:
+        super().__init__(**kwargs)
+        self._owner_thread = threading.get_ident()
+        self.thread_ids: set[int] = {self._owner_thread}
+
+    def _record(self, method: str) -> None:
+        ident = threading.get_ident()
+        self.thread_ids.add(ident)
+        if ident != self._owner_thread:
+            _ThreadAffinityFakeSandbox.affinity_failures.append(
+                f"{method} called from thread {ident}, expected {self._owner_thread}"
+            )
+
+    def register_tool(self, name_or_tool: Any, callback: Any | None = None) -> None:
+        self._record("register_tool")
+        super().register_tool(name_or_tool, callback)
+
+    def allow_domain(self, target: str, methods: list[str] | None = None) -> None:
+        self._record("allow_domain")
+        super().allow_domain(target, methods)
+
+    def run(self, code: str) -> _FakeResult:
+        self._record("run")
+        return super().run(code)
+
+    def snapshot(self) -> str:
+        self._record("snapshot")
+        return super().snapshot()
+
+    def restore(self, snapshot: Any) -> None:
+        self._record("restore")
+        super().restore(snapshot)
+
+
+async def test_sandbox_calls_are_pinned_to_owning_worker_thread(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Regression: WasmSandbox is unsendable; every sandbox call must run on its owner thread."""
+    _ThreadAffinityFakeSandbox.instances.clear()
+    _ThreadAffinityFakeSandbox.affinity_failures.clear()
+    monkeypatch.setattr(execute_code_module, "_load_sandbox_class", lambda: _ThreadAffinityFakeSandbox)
+
+    execute_code = HyperlightExecuteCodeTool()
+
+    # Invoke many times concurrently; asyncio.to_thread will spread these across the default
+    # executor's worker threads, which previously caused PyO3 to panic when a different thread
+    # touched the cached sandbox.
+    results = await asyncio.gather(*[execute_code.invoke(arguments={"code": "None"}) for _ in range(8)])
+    for result in results:
+        assert result[0].type == "text"
+
+    assert _ThreadAffinityFakeSandbox.affinity_failures == []
+    assert len(_ThreadAffinityFakeSandbox.instances) == 1
+    sandbox = _ThreadAffinityFakeSandbox.instances[0]
+    # All sandbox-touching calls must have stayed on a single owning thread, distinct from the
+    # caller thread that asyncio.to_thread used for dispatch.
+    assert sandbox.thread_ids == {sandbox._owner_thread}
+    assert sandbox._owner_thread != threading.get_ident()
+
+
+async def test_sandbox_owner_thread_persists_across_dispatch_threads(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Sequential calls landing on different dispatch threads still share one sandbox thread."""
+    _ThreadAffinityFakeSandbox.instances.clear()
+    _ThreadAffinityFakeSandbox.affinity_failures.clear()
+    monkeypatch.setattr(execute_code_module, "_load_sandbox_class", lambda: _ThreadAffinityFakeSandbox)
+
+    execute_code = HyperlightExecuteCodeTool()
+
+    for _ in range(5):
+        result = await execute_code.invoke(arguments={"code": "None"})
+        assert result[0].type == "text"
+
+    assert _ThreadAffinityFakeSandbox.affinity_failures == []
+    assert len(_ThreadAffinityFakeSandbox.instances) == 1
+
+
+def test_sandbox_registry_close_shuts_down_workers(monkeypatch: pytest.MonkeyPatch) -> None:
+    _FakeSandbox.instances.clear()
+    monkeypatch.setattr(execute_code_module, "_load_sandbox_class", lambda: _FakeSandbox)
+
+    registry = execute_code_module._SandboxRegistry()
+    execute_code = HyperlightExecuteCodeTool(_registry=registry)
+    asyncio.run(execute_code.invoke(arguments={"code": "None"}))
+
+    entries = list(registry._entries.values())
+    assert len(entries) == 1
+    worker = entries[0].worker
+
+    registry.close()
+
+    assert registry._entries == {}
+    # Submitting after shutdown must fail; this proves the executor was actually torn down.
+    with pytest.raises(RuntimeError):
+        worker.submit(lambda: None)
+
+
+def test_sandbox_registry_close_releases_per_entry_resources(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+    """close() must invoke any sandbox close hook and release temp directories."""
+
+    close_calls: list[int] = []
+
+    class _ClosableFakeSandbox(_FakeSandbox):
+        def close(self) -> None:
+            close_calls.append(1)
+
+    _FakeSandbox.instances.clear()
+    monkeypatch.setattr(execute_code_module, "_load_sandbox_class", lambda: _ClosableFakeSandbox)
+
+    workspace = tmp_path / "workspace"
+    workspace.mkdir()
+    registry = execute_code_module._SandboxRegistry()
+    execute_code = HyperlightExecuteCodeTool(workspace_root=workspace, _registry=registry)
+    asyncio.run(execute_code.invoke(arguments={"code": "None"}))
+
+    entries = list(registry._entries.values())
+    assert len(entries) == 1
+    entry = entries[0]
+    assert entry.input_dir is not None and entry.output_dir is not None
+    input_path = Path(entry.input_dir.name)
+    output_path = Path(entry.output_dir.name)
+    assert input_path.exists() and output_path.exists()
+
+    registry.close()
+
+    assert close_calls == [1]
+    assert not input_path.exists()
+    assert not output_path.exists()
+
+
+async def test_make_sandbox_callback_returns_native_dict() -> None:
+    """Host tool returning a dict must be forwarded as a native dict (no repr round-trip)."""
+
+    @tool
+    def get_weather(city: str) -> dict[str, Any]:
+        """Get weather."""
+        return {"city": city, "temp_c": 21.5}
+
+    callback = execute_code_module._make_sandbox_callback(get_weather)
+    result = callback(city="Seattle")
+
+    assert isinstance(result, dict)
+    assert result == {"city": "Seattle", "temp_c": 21.5}
+
+
+async def test_make_sandbox_callback_bypasses_user_result_parser() -> None:
+    """Documented behavior change: result_parser is bypassed in the sandbox path."""
+
+    parser_calls: list[Any] = []
+
+    def parser(value: Any) -> str:
+        parser_calls.append(value)
+        return "PARSED"
+
+    @tool(result_parser=parser)
+    def make_payload() -> dict[str, int]:
+        """Returns a dict."""
+        return {"a": 1, "b": 2}
+
+    callback = execute_code_module._make_sandbox_callback(make_payload)
+    result = callback()
+
+    assert result == {"a": 1, "b": 2}
+    assert parser_calls == [], "result_parser must not run on the sandbox path"
+
+
+async def test_make_sandbox_callback_propagates_exceptions() -> None:
+    @tool
+    def boom(x: int) -> int:
+        """Always fails."""
+        raise RuntimeError("nope")
+
+    callback = execute_code_module._make_sandbox_callback(boom)
+    with pytest.raises(RuntimeError, match="nope"):
+        callback(x=1)

python/packages/lab/pyproject.toml

@@ -4,7 +4,7 @@ description = "Experimental modules for Microsoft Agent Framework"
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -22,7 +22,7 @@ classifiers = [
   "Programming Language :: Python :: 3.14",
 ]
 dependencies = [
-  "agent-framework-core>=1.1.0,<2",
+  "agent-framework-core>=1.1.1,<2",
 ]
 
 [project.optional-dependencies]

python/packages/mem0/pyproject.toml

@@ -4,7 +4,7 @@ description = "Mem0 integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://aka.ms/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "mem0ai>=1.0.0,<2",
 ]
 

python/packages/ollama/pyproject.toml

@@ -4,7 +4,7 @@ description = "Ollama integration for Microsoft Agent Framework."
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260421"
+version = "1.0.0b260423"
 license-files = ["LICENSE"]
 urls.homepage = "https://learn.microsoft.com/en-us/agent-framework/"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
 dependencies = [
-    "agent-framework-core>=1.1.0,<2",
+    "agent-framework-core>=1.1.1,<2",
     "ollama>=0.5.3,<0.5.4",
 ]
 

python/packages/openai/agent_framework_openai/_chat_client.py

@@ -1405,7 +1405,7 @@ class RawOpenAIChatClient(  # type: ignore[misc]
                         else "auto",
                     }
                     file_id = content.additional_properties.get("file_id") if content.additional_properties else None
-                    if file_id:
+                    if file_id is not None:
                         result["file_id"] = file_id
                     return result
                 if content.has_top_level_media_type("audio"):
@@ -2028,6 +2028,7 @@ class RawOpenAIChatClient(  # type: ignore[misc]
         local_shell_tool_name = self._get_local_shell_tool_name(options.get("tools"))
         conversation_id: str | None = None
         response_id: str | None = None
+        created_at: str | None = None
         continuation_token: OpenAIContinuationToken | None = None
         model = self.model
         match event.type:
@@ -2209,6 +2210,9 @@ class RawOpenAIChatClient(  # type: ignore[misc]
                 response_id = event.response.id
                 conversation_id = self._get_conversation_id(event.response, options.get("store"))
                 model = event.response.model
+                created_at = datetime.fromtimestamp(event.response.created_at, tz=timezone.utc).strftime(
+                    "%Y-%m-%dT%H:%M:%S.%fZ"
+                )
                 if event.response.usage:
                     usage = self._parse_usage_from_openai(event.response.usage)
                     if usage:
@@ -2589,6 +2593,7 @@ class RawOpenAIChatClient(  # type: ignore[misc]
             response_id=response_id,
             role="assistant",
             model=model,
+            created_at=created_at,
             continuation_token=continuation_token,
             additional_properties=metadata,
             raw_representation=event,