Roger Barreto eb709d8fc9 .NET: Update FoundryAgent to address HostedAgents strict URL routing (#5677)
* .NET: Foundry agent-endpoint constructor uses ProjectOpenAIClient directly to fix hosted-agent URL routing

Fixes the experimental FoundryAgent(Uri agentEndpoint, AuthenticationTokenProvider, ...)
constructor so it actually works against Foundry hosted agents.

The previous implementation routed through AzureAIProjectChatClient, which
internally called aiProjectClient.GetProjectOpenAIClient().GetProjectResponsesClientForAgent(...).
For an agent-endpoint URL of the canonical shape

  https://<host>/api/projects/<project>/agents/<agentName>/endpoint/protocols/openai

the chain produced

  POST https://<host>/api/projects/<project>/openai/v1/responses

(project-level path, no /agents/ segment). The Foundry service rejects this with
HTTP 400 "Hosted agents can only be called through the agent endpoint:
.../agents/<agentName>/endpoint/protocols/openai/responses".

The constructor also extracted the agent name via
agentEndpoint.Segments[^1].TrimEnd('/'), which returns "openai" (the last segment),
not the agent name.

What changed
- Public ctor signature: clientOptions parameter type changed from
  AIProjectClientOptions? to ProjectOpenAIClientOptions?. The constructor is
  fundamentally building a ProjectOpenAIClient; accepting AIProjectClientOptions
  was a leaky abstraction whose translation silently dropped any pipeline
  policies the caller added via AddPolicy(...). With the direct type, caller
  policies pass through to the per-agent traffic verbatim.
- Per-agent client construction: `new ProjectOpenAIClient(BearerTokenPolicy, ProjectOpenAIClientOptions)`
  with Endpoint and AgentName set, then `GetProjectResponsesClient().AsIChatClient()`.
  The SDK auto-appends ?api-version=v1 when AgentName is set.
- New private static ParseAgentEndpoint helper: single source of truth for both
  agent-name extraction and project-root derivation. Tolerates trailing slash,
  case variants on /agents/ and the suffix segment, strips query/fragment, and
  throws ArgumentException with paramName=nameof(agentEndpoint) for malformed input.
- Project-level client (used by CreateConversationSessionAsync) is built fresh
  from the derived project root with primitive properties copied
  (RetryPolicy/NetworkTimeout/Transport/UserAgentApplicationId) plus MEAI UA.
- New GetService<ProjectOpenAIClient>() entry alongside the existing
  GetService<AIProjectClient>() (the latter returns null in agent-endpoint mode
  since no AIProjectClient is constructed on that path).
- Endpoint and AgentName on caller-supplied ProjectOpenAIClientOptions are
  overridden by values derived from agentEndpoint.

Compatibility
- FoundryAgent is [Experimental(OPENAI001)]. No GA surface touched. The Foundry
  project does not maintain PublicAPI.*.txt baselines so there is no shipped
  baseline to update.
- The Microsoft.Agents.AI.Foundry csproj pins
  Azure.AI.Projects to VersionOverride 2.1.0-beta.1 (matching what the IT and
  hosting projects already use); the central pin in Directory.Packages.props
  stays at 2.0.0.
- WireClientHeaders from PR #5652 is invoked on the agent-endpoint path so
  per-call x-client-* headers behave identically across both ctors.

Tests
- 23 new unit tests in FoundryAgentTests.cs:
  - 12 for the agent-endpoint constructor (URL routing for non-streaming and
    streaming, conversations URL shape, MEAI UA stamping, caller-policy
    passthrough on the per-agent pipeline, Endpoint/AgentName override
    semantics, GetService matrix, ProjectOpenAIClient propagation,
    UserAgentApplicationId propagation, null-arg validation, ID/Name slug)
  - 9 for ParseAgentEndpoint (standard shape, trailing slash, casing,
    sovereign-cloud host without /api/projects/ literal prefix, special chars
    in agent name, query/fragment stripping, three negative cases)
  - 2 null-arg tests for the public ctor
- All 250 Microsoft.Agents.AI.Foundry.UnitTests pass (was 221 baseline plus
  29 from PR #5652 plus 23 new in this PR equals 273; pre-existing tests
  collapsed by the rebase merge keep the total at 250).
- All 225 Microsoft.Agents.AI.Foundry.Hosting.UnitTests pass; no behavioral
  change to the hosting layer.
- dotnet build clean across net8/9/10/netstandard2.0/net472 with
  TreatWarningsAsErrors=true.
- dotnet format --verify-no-changes clean for the touched src and test projects.

* .NET: Bump central Azure.AI.Projects pin to 2.1.0-beta.1 and flip Microsoft.Agents.AI.Foundry to preview

Required to fix the NU1109 downgrade chain that broke CI on the agent-endpoint
constructor rewire (#5677). Microsoft.Agents.AI.Foundry now depends on
ProjectOpenAIClientOptions.AgentName and the (AuthenticationPolicy, options)
constructor that only exist in Azure.AI.Projects 2.1.0-beta.1.

Changes:
* Directory.Packages.props: Azure.AI.Projects 2.0.0 -> 2.1.0-beta.1.
* Microsoft.Agents.AI.Foundry.csproj: drop IsReleased=true so the package ships
  as preview (matches the beta SDK we now depend on). Add a comment noting the
  flip is temporary and should revert once Azure.AI.Projects ships a stable
  2.1.0.
* Drop redundant VersionOverride="2.1.0-beta.1" from the 10 csprojs that had it
  as a workaround; the central pin now suffices.

Verified:
* dotnet build agent-framework-dotnet.slnx --warnaserror clean across all TFMs.
* Microsoft.Agents.AI.Foundry.UnitTests 250/250 pass.
* Microsoft.Agents.AI.Foundry.Hosting.UnitTests 211/211 pass.
* dotnet format --verify-no-changes clean for the touched src and test projects.
eb709d8fc9 · 2026-05-08 14:46:52 +00:00
2,044 Commits
2025-10-30 20:29:01 +00:00
2025-04-28 12:54:43 -07:00
2025-04-28 12:54:42 -07:00

Microsoft Agent Framework

Welcome to Microsoft Agent Framework!

Microsoft Foundry Discord MS Learn Documentation PyPI NuGet GitHub stars

Microsoft Agent Framework (MAF) is an open, multi-language framework for building production-grade AI agents and multi-agent workflows in .NET and Python.

Microsoft Agent Framework is built for teams taking agents from prototype to production. It provides a consistent foundation for building, orchestrating, and operating agent systems across Python and .NET, while keeping architecture choices open as requirements evolve, and supports a broad ecosystem including Microsoft Foundry, Azure OpenAI, OpenAI, and the GitHub Copilot SDK, with samples and hosting patterns for both local development and cloud deployment.

Watch the full Agent Framework introduction (30 min)

Watch the full Agent Framework introduction (30 min)

Is this the right framework for you?

MAF is a strong fit if you:

  • are building agents and workflows you expect to run in production,
  • need orchestration beyond a single prompt or stateless chat loop,
  • want graph-based patterns such as sequential, concurrent, handoff, and group collaboration,
  • care about durability, restartability, observability, governance, or human-in-the-loop control,
  • need provider flexibility so your architecture can evolve without major rewrites.

Key Features

Explore new MAF capabilities and real implementation patterns on the official blog.

  • Python and C#/.NET Support: Full framework support for both Python and C#/.NET implementations with consistent APIs
  • Multiple Agent Provider Support: Support for various LLM providers with more being added continuously
  • Middleware: Flexible middleware system for request/response processing, exception handling, and custom pipelines
  • Orchestration Patterns & Workflows: Build multi-agent systems with graph-based workflows supporting sequential, concurrent, handoff, and group collaboration patterns; includes checkpointing, streaming, human-in-the-loop, and time-travel
  • Foundry Hosted Agents (new): Deploy and host your agents to Foundry-hosted infrastructure with just 2 additional lines of code
  • Observability: Built-in OpenTelemetry integration for distributed tracing, monitoring, and debugging
  • Declarative Agents: Define agents using YAML for faster setup and versioning
  • Agent Skills: Build domain-specific knowledge bases from multiple sources—files, inline code, class libraries—for agents to discover and use
  • AF Labs: Experimental packages for cutting-edge features including benchmarking, reinforcement learning, and research initiatives
  • DevUI: Interactive developer UI for agent development, testing, and debugging workflows

Table of Contents

Getting Started

Installation

Python

pip install agent-framework
# This will install all sub-packages, see `python/packages` for individual packages.
# It may take a minute on first install on Windows.

.NET

dotnet add package Microsoft.Agents.AI
# For Foundry integration (used in the .NET quickstart below):
dotnet add package Microsoft.Agents.AI.Foundry
dotnet add package Azure.AI.Projects
dotnet add package Azure.Identity

Learning Resources

Quickstart

Basic Agent - Python

Create a simple Azure Responses Agent that writes a haiku about the Microsoft Agent Framework

# pip install agent-framework
# Use `az login` to authenticate with Azure CLI
import os
import asyncio
from agent_framework import Agent
from agent_framework.foundry import FoundryChatClient
from azure.identity import AzureCliCredential


async def main():
    # Initialize a chat agent with Microsoft Foundry
    # the endpoint, deployment name, and api version can be set via environment variables
    # or they can be passed in directly to the FoundryChatClient constructor
    agent = Agent(
      client=FoundryChatClient(
          credential=AzureCliCredential(),
          # project_endpoint=os.environ["FOUNDRY_PROJECT_ENDPOINT"],
          # model=os.environ["FOUNDRY_MODEL_DEPLOYMENT_NAME"],
      ),
      name="HaikuAgent",
      instructions="You are an upbeat assistant that writes beautifully.",
    )

    print(await agent.run("Write a haiku about Microsoft Agent Framework."))

if __name__ == "__main__":
    asyncio.run(main())

Basic Agent - .NET

Create a simple Agent, using Microsoft Foundry that writes a haiku about the Microsoft Agent Framework

// This sample shows how to create and run a basic agent with AIProjectClient.AsAIAgent(...).

using Azure.AI.Projects;
using Azure.Identity;
using Microsoft.Agents.AI;

string endpoint = Environment.GetEnvironmentVariable("AZURE_AI_PROJECT_ENDPOINT") ?? throw new InvalidOperationException("AZURE_AI_PROJECT_ENDPOINT is not set.");
string deploymentName = Environment.GetEnvironmentVariable("AZURE_AI_MODEL_DEPLOYMENT_NAME") ?? "gpt-5.4-mini";

AIAgent agent =
    new AIProjectClient(new Uri(endpoint), new DefaultAzureCredential())
    .AsAIAgent(model: deploymentName, instructions: "You are an upbeat assistant that writes beautifully.", name: "HaikuAgent");

// Once you have the agent, you can invoke it like any other AIAgent.
Console.WriteLine(await agent.RunAsync("Write a haiku about Microsoft Agent Framework."));

More Examples & Samples

Python

  • Getting Started: progressive tutorial from hello-world to hosting
  • Agent Concepts: deep-dive samples by topic (tools, middleware, providers, etc.)
  • Workflows: workflow creation and integration with agents
  • Hosting: A2A, Azure Functions, Durable Task hosting
  • End-to-End: full applications, evaluation, and demos

.NET

Community & Feedback

  • Found a bug? File a GitHub issue to help us improve.
  • Enjoying MAF? GitHub stars to show your support and help others discover the project.
  • Have questions? Join our Discord or visit weekly office hours.

Troubleshooting

Authentication

Problem Cause Fix
Authentication errors when using Azure credentials Not signed in to Azure CLI Run az login before starting your app
API key errors Wrong or missing API key Verify the key and ensure it's for the correct resource/provider

Tip: DefaultAzureCredential is convenient for development but in production, consider using a specific credential (e.g., ManagedIdentityCredential) to avoid latency issues, unintended credential probing, and potential security risks from fallback mechanisms.

Environment Variables

For environment variable configuration specific to each sample, refer to the README in the sample directory (Python samples | .NET samples).

Contributor Resources

Important Notes

Important

If you use Microsoft Agent Framework to build applications that operate with any third-party servers, agents, code, or non-Azure Direct models (“Third-Party Systems”), you do so at your own risk. Third-Party Systems are Non-Microsoft Products under the Microsoft Product Terms and are governed by their own third-party license terms. You are responsible for any usage and associated costs.

We recommend reviewing all data being shared with and received from Third-Party Systems and being cognizant of third-party practices for handling, sharing, retention and location of data. It is your responsibility to manage whether your data will flow outside of your organizations Azure compliance and geographic boundaries and any related implications, and that appropriate permissions, boundaries and approvals are provisioned.

You are responsible for carefully reviewing and testing applications you build using Microsoft Agent Framework in the context of your specific use cases, and making all appropriate decisions and customizations. This includes implementing your own responsible AI mitigations such as metaprompt, content filters, or other safety systems, and ensuring your applications meet appropriate quality, reliability, security, and trustworthiness standards. See also: Transparency FAQ

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