Python: basic python a2a support (#906)

* basic python a2a support * fixes * small fixes --------- Co-authored-by: Eric Zhu <ekzhu@users.noreply.github.com>
2026-06-16 21:04:09 +08:00 · 2025-09-29 10:53:45 -07:00
parent fe6492ce60
commit c102706146
13 changed files with 1296 additions and 2 deletions
@@ -0,0 +1,21 @@
+    MIT License
+
+    Copyright (c) Microsoft Corporation.
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE
@@ -0,0 +1,21 @@
+# Get Started with Microsoft Agent Framework A2A
+
+Please install this package as the extra for `agent-framework`:
+
+```bash
+pip install agent-framework[a2a]
+```
+
+## A2A Agent Integration
+
+The A2A agent integration enables communication with remote A2A-compliant agents using the standardized A2A protocol. This allows your Agent Framework applications to connect to agents running on different platforms, languages, or services.
+
+### Basic Usage Example
+
+See the [A2A agent examples](https://github.com/microsoft/agent-framework/tree/main/python/samples/getting_started/agents/a2a/) which demonstrate:
+
+- Connecting to remote A2A agents
+- Sending messages and receiving responses
+- Handling different content types (text, files, data)
+- Streaming responses and real-time interaction
+
@@ -0,0 +1,15 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+import importlib.metadata
+
+from ._agent import A2AAgent
+
+try:
+    __version__ = importlib.metadata.version(__name__)
+except importlib.metadata.PackageNotFoundError:
+    __version__ = "0.0.0"  # Fallback for development mode
+
+__all__ = [
+    "A2AAgent",
+    "__version__",
+]
@@ -0,0 +1,383 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+import base64
+import json
+import re
+import uuid
+from collections.abc import AsyncIterable, Sequence
+from typing import Any
+
+import httpx
+from a2a.client import Client, ClientConfig, ClientFactory, minimal_agent_card
+from a2a.types import (
+    AgentCard,
+    Artifact,
+    FilePart,
+    FileWithBytes,
+    FileWithUri,
+    Message,
+    Task,
+    TaskState,
+    TextPart,
+    TransportProtocol,
+)
+from a2a.types import Message as A2AMessage
+from a2a.types import Part as A2APart
+from a2a.types import Role as A2ARole
+from agent_framework import (
+    AgentRunResponse,
+    AgentRunResponseUpdate,
+    AgentThread,
+    BaseAgent,
+    ChatMessage,
+    Contents,
+    DataContent,
+    Role,
+    TextContent,
+    UriContent,
+    prepend_agent_framework_to_user_agent,
+)
+
+__all__ = ["A2AAgent"]
+
+URI_PATTERN = re.compile(r"^data:(?P<media_type>[^;]+);base64,(?P<base64_data>[A-Za-z0-9+/=]+)$")
+TERMINAL_TASK_STATES = [
+    TaskState.completed,
+    TaskState.failed,
+    TaskState.canceled,
+    TaskState.rejected,
+]
+
+
+def _get_uri_data(uri: str) -> str:
+    match = URI_PATTERN.match(uri)
+    if not match:
+        raise ValueError(f"Invalid data URI format: {uri}")
+
+    return match.group("base64_data")
+
+
+class A2AAgent(BaseAgent):
+    """Agent-to-Agent (A2A) protocol implementation.
+
+    Wraps an A2A Client to connect the Agent Framework with external A2A-compliant agents
+    via HTTP/JSON-RPC. Converts framework ChatMessages to A2A Messages on send, and converts
+    A2A responses (Messages/Tasks) back to framework types. Inherits BaseAgent capabilities
+    while managing the underlying A2A protocol communication.
+
+    Can be initialized with a URL, AgentCard, or existing A2A Client instance.
+    """
+
+    client: Client
+    _http_client: httpx.AsyncClient | None = None
+
+    def __init__(
+        self,
+        *,
+        name: str | None = None,
+        id: str | None = None,
+        description: str | None = None,
+        agent_card: AgentCard | None = None,
+        url: str | None = None,
+        client: Client | None = None,
+        http_client: httpx.AsyncClient | None = None,
+    ) -> None:
+        """Initialize the A2AAgent.
+
+        Args:
+            name: The name of the agent.
+            id: The unique identifier for the agent, will be created automatically if not provided.
+            description: A brief description of the agent's purpose.
+            agent_card: The agent card for the agent.
+            url: The URL for the A2A server.
+            client: The A2A client for the agent.
+            http_client: Optional httpx.AsyncClient to use.
+        """
+        if client is None:
+            if agent_card is None:
+                if url is None:
+                    raise ValueError("Either agent_card or url must be provided")
+                # Create minimal agent card from URL
+                agent_card = minimal_agent_card(url, [TransportProtocol.jsonrpc])
+
+            # Create or use provided httpx client
+            if http_client is None:
+                timeout = httpx.Timeout(
+                    connect=10.0,  # 10 seconds to establish connection
+                    read=60.0,  # 60 seconds to read response (A2A operations can take time)
+                    write=10.0,  # 10 seconds to send request
+                    pool=5.0,  # 5 seconds to get connection from pool
+                )
+                headers = prepend_agent_framework_to_user_agent()
+                http_client = httpx.AsyncClient(timeout=timeout, headers=headers)
+                self._http_client = http_client  # Store for cleanup
+
+            # Create A2A client using factory
+            config = ClientConfig(
+                httpx_client=http_client,
+                supported_transports=[TransportProtocol.jsonrpc],
+            )
+            factory = ClientFactory(config)
+            client = factory.create(agent_card)
+
+        args: dict[str, Any] = {"client": client}
+        if name:
+            args["name"] = name
+        if id:
+            args["id"] = id
+        if description:
+            args["description"] = description
+        super().__init__(**args)
+
+    async def __aenter__(self) -> "A2AAgent":
+        """Async context manager entry."""
+        return self
+
+    async def __aexit__(
+        self,
+        exc_type: type[BaseException] | None,
+        exc_val: BaseException | None,
+        exc_tb: Any,
+    ) -> None:
+        """Async context manager exit with httpx client cleanup."""
+        # Close our httpx client if we created it
+        if self._http_client is not None:
+            await self._http_client.aclose()
+
+    async def run(
+        self,
+        messages: str | ChatMessage | list[str] | list[ChatMessage] | None = None,
+        *,
+        thread: AgentThread | None = None,
+        **kwargs: Any,
+    ) -> AgentRunResponse:
+        """Get a response from the agent.
+
+        This method returns the final result of the agent's execution
+        as a single AgentRunResponse object. The caller is blocked until
+        the final result is available.
+
+        Args:
+            messages: The message(s) to send to the agent.
+            thread: The conversation thread associated with the message(s).
+            kwargs: Additional keyword arguments.
+
+        Returns:
+            An agent response item.
+        """
+        # Collect all updates and use framework to consolidate updates into response
+        updates = [update async for update in self.run_stream(messages, thread=thread, **kwargs)]
+        return AgentRunResponse.from_agent_run_response_updates(updates)
+
+    async def run_stream(
+        self,
+        messages: str | ChatMessage | list[str] | list[ChatMessage] | None = None,
+        *,
+        thread: AgentThread | None = None,
+        **kwargs: Any,
+    ) -> AsyncIterable[AgentRunResponseUpdate]:
+        """Run the agent as a stream.
+
+        This method will return the intermediate steps and final results of the
+        agent's execution as a stream of AgentRunResponseUpdate objects to the caller.
+
+        Args:
+            messages: The message(s) to send to the agent.
+            thread: The conversation thread associated with the message(s).
+            kwargs: Additional keyword arguments.
+
+        Yields:
+            An agent response item.
+        """
+        messages = self._normalize_messages(messages)
+        a2a_message = self._chat_message_to_a2a_message(messages[-1])
+
+        response_stream = self.client.send_message(a2a_message)
+
+        async for item in response_stream:
+            if isinstance(item, Message):
+                # Process A2A Message
+                contents = self._a2a_parts_to_contents(item.parts)
+                yield AgentRunResponseUpdate(
+                    contents=contents,
+                    role=Role.ASSISTANT if item.role == A2ARole.agent else Role.USER,
+                    response_id=str(getattr(item, "message_id", uuid.uuid4())),
+                    raw_representation=item,
+                )
+            elif isinstance(item, tuple) and len(item) == 2:  # ClientEvent = (Task, UpdateEvent)
+                task, _update_event = item
+                if isinstance(task, Task) and task.status.state in TERMINAL_TASK_STATES:
+                    # Convert Task artifacts to ChatMessages and yield as separate updates
+                    task_messages = self._task_to_chat_messages(task)
+                    if task_messages:
+                        for message in task_messages:
+                            # Use the artifact's ID from raw_representation as message_id for unique identification
+                            artifact_id = getattr(message.raw_representation, "artifact_id", None)
+                            yield AgentRunResponseUpdate(
+                                contents=message.contents,
+                                role=message.role,
+                                response_id=task.id,
+                                message_id=artifact_id,
+                                raw_representation=task,
+                            )
+                    else:
+                        # Empty task
+                        yield AgentRunResponseUpdate(
+                            contents=[],
+                            role=Role.ASSISTANT,
+                            response_id=task.id,
+                            raw_representation=task,
+                        )
+            else:
+                # Unknown response type
+                msg = f"Only Message and Task responses are supported from A2A agents. Received: {type(item)}"
+                raise NotImplementedError(msg)
+
+    def _chat_message_to_a2a_message(self, message: ChatMessage) -> A2AMessage:
+        """Convert a ChatMessage to an A2A Message.
+
+        Transforms Agent Framework ChatMessage objects into A2A protocol Messages by:
+        - Converting all message contents to appropriate A2A Part types
+        - Mapping text content to TextPart objects
+        - 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
+        """
+        parts: list[A2APart] = []
+        if not message.contents:
+            raise ValueError("ChatMessage.contents is empty; cannot convert to A2AMessage.")
+
+        # Process ALL contents
+        for content in message.contents:
+            match content.type:
+                case "text":
+                    parts.append(
+                        A2APart(
+                            root=TextPart(
+                                text=content.text,
+                                metadata=content.additional_properties,
+                            )
+                        )
+                    )
+                case "error":
+                    parts.append(
+                        A2APart(
+                            root=TextPart(
+                                text=content.message or "An error occurred.",
+                                metadata=content.additional_properties,
+                            )
+                        )
+                    )
+                case "uri":
+                    parts.append(
+                        A2APart(
+                            root=FilePart(
+                                file=FileWithUri(
+                                    uri=content.uri,
+                                    mime_type=content.media_type,
+                                ),
+                                metadata=content.additional_properties,
+                            )
+                        )
+                    )
+                case "data":
+                    parts.append(
+                        A2APart(
+                            root=FilePart(
+                                file=FileWithBytes(
+                                    bytes=_get_uri_data(content.uri),
+                                    mime_type=content.media_type,
+                                ),
+                                metadata=content.additional_properties,
+                            )
+                        )
+                    )
+                case "hosted_file":
+                    parts.append(
+                        A2APart(
+                            root=FilePart(
+                                file=FileWithUri(
+                                    uri=content.file_id,
+                                    mime_type=None,  # HostedFileContent doesn't specify media_type
+                                ),
+                                metadata=content.additional_properties,
+                            )
+                        )
+                    )
+                case _:
+                    raise ValueError(f"Unknown content type: {content.type}")
+
+        return A2AMessage(
+            role=A2ARole("user"),
+            parts=parts,
+            message_id=message.message_id or uuid.uuid4().hex,
+            metadata=message.additional_properties,
+        )
+
+    def _a2a_parts_to_contents(self, parts: Sequence[A2APart]) -> list[Contents]:
+        """Convert A2A Parts to Agent Framework Contents.
+
+        Transforms A2A protocol Parts into framework-native Content objects,
+        handling text, file (URI/bytes), and data parts with metadata preservation.
+        """
+        contents: list[Contents] = []
+        for part in parts:
+            inner_part = part.root
+            match inner_part.kind:
+                case "text":
+                    contents.append(
+                        TextContent(
+                            text=inner_part.text,
+                            additional_properties=inner_part.metadata,
+                            raw_representation=inner_part,
+                        )
+                    )
+                case "file":
+                    if isinstance(inner_part.file, FileWithUri):
+                        contents.append(
+                            UriContent(
+                                uri=inner_part.file.uri,
+                                media_type=inner_part.file.mime_type or "",
+                                additional_properties=inner_part.metadata,
+                                raw_representation=inner_part,
+                            )
+                        )
+                    elif isinstance(inner_part.file, FileWithBytes):
+                        contents.append(
+                            DataContent(
+                                data=base64.b64decode(inner_part.file.bytes),
+                                media_type=inner_part.file.mime_type or "",
+                                additional_properties=inner_part.metadata,
+                                raw_representation=inner_part,
+                            )
+                        )
+                case "data":
+                    contents.append(
+                        TextContent(
+                            text=json.dumps(inner_part.data),
+                            additional_properties=inner_part.metadata,
+                            raw_representation=inner_part,
+                        )
+                    )
+                case _:
+                    raise ValueError(f"Unknown Part kind: {inner_part.kind}")
+        return contents
+
+    def _task_to_chat_messages(self, task: Task) -> list[ChatMessage]:
+        """Convert A2A Task artifacts to ChatMessages with ASSISTANT role."""
+        messages: list[ChatMessage] = []
+
+        if task.artifacts is not None:
+            for artifact in task.artifacts:
+                messages.append(self._artifact_to_chat_message(artifact))
+
+        return messages
+
+    def _artifact_to_chat_message(self, artifact: Artifact) -> ChatMessage:
+        """Convert A2A Artifact to ChatMessage using part contents."""
+        contents = self._a2a_parts_to_contents(artifact.parts)
+        return ChatMessage(
+            role=Role.ASSISTANT,
+            contents=contents,
+            raw_representation=artifact,
+        )
@@ -0,0 +1,89 @@
+[project]
+name = "agent-framework-a2a"
+description = "A2A integration for Microsoft Agent Framework."
+authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
+readme = "README.md"
+requires-python = ">=3.10"
+version = "0.1.0b1"
+license-files = ["LICENSE"]
+urls.homepage = "https://learn.microsoft.com/en-us/semantic-kernel/overview/"
+urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
+urls.release_notes = "https://github.com/microsoft/agent-framework/releases?q=tag%3Apython-1&expanded=true"
+urls.issues = "https://github.com/microsoft/agent-framework/issues"
+classifiers = [
+  "License :: OSI Approved :: MIT License",
+  "Development Status :: 5 - Production/Stable",
+  "Intended Audience :: Developers",
+  "Programming Language :: Python :: 3",
+  "Programming Language :: Python :: 3.10",
+  "Programming Language :: Python :: 3.11",
+  "Programming Language :: Python :: 3.12",
+  "Programming Language :: Python :: 3.13",
+  "Framework :: Pydantic :: 2",
+  "Typing :: Typed",
+]
+dependencies = [
+    "agent-framework",
+    "a2a-sdk>=0.3.5",
+]
+
+[tool.uv]
+prerelease = "if-necessary-or-explicit"
+environments = [
+    "sys_platform == 'darwin'",
+    "sys_platform == 'linux'",
+    "sys_platform == 'win32'"
+]
+
+[tool.uv-dynamic-versioning]
+fallback-version = "0.0.0"
+[tool.pytest.ini_options]
+testpaths = 'tests'
+addopts = "-ra -q -r fEX"
+asyncio_mode = "auto"
+asyncio_default_fixture_loop_scope = "function"
+filterwarnings = [
+    "ignore:Support for class-based `config` is deprecated:DeprecationWarning:pydantic.*"
+]
+timeout = 120
+
+[tool.ruff]
+extend = "../../pyproject.toml"
+
+[tool.coverage.run]
+omit = [
+    "**/__init__.py"
+]
+
+[tool.pyright]
+extend = "../../pyproject.toml"
+exclude = ['tests']
+
+[tool.mypy]
+plugins = ['pydantic.mypy']
+strict = true
+python_version = "3.10"
+ignore_missing_imports = true
+disallow_untyped_defs = true
+no_implicit_optional = true
+check_untyped_defs = true
+warn_return_any = true
+show_error_codes = true
+warn_unused_ignores = false
+disallow_incomplete_defs = true
+disallow_untyped_decorators = true
+
+[tool.bandit]
+targets = ["agent_framework_a2a"]
+exclude_dirs = ["tests"]
+
+[tool.poe]
+executor.type = "uv"
+include = "../../shared_tasks.toml"
+[tool.poe.tasks]
+mypy = "mypy --config-file $POE_ROOT/pyproject.toml agent_framework_a2a"
+test = "pytest --cov=agent_framework_a2a --cov-report=term-missing:skip-covered tests"
+
+[build-system]
+requires = ["flit-core >= 3.9,<4.0"]
+build-backend = "flit_core.buildapi"
@@ -0,0 +1,498 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+from collections.abc import AsyncIterator
+from typing import Any
+from unittest.mock import AsyncMock, MagicMock
+from uuid import uuid4
+
+from a2a.types import Artifact, DataPart, FilePart, FileWithUri, Message, Part, Task, TaskState, TaskStatus, TextPart
+from a2a.types import Role as A2ARole
+from agent_framework import (
+    AgentRunResponse,
+    AgentRunResponseUpdate,
+    ChatMessage,
+    DataContent,
+    ErrorContent,
+    HostedFileContent,
+    Role,
+    TextContent,
+    UriContent,
+)
+from agent_framework.a2a import A2AAgent
+from pytest import fixture, raises
+
+from agent_framework_a2a._agent import _get_uri_data  # type: ignore
+
+
+class MockA2AClient:
+    """Mock implementation of A2A Client for testing."""
+
+    def __init__(self) -> None:
+        self.call_count: int = 0
+        self.responses: list[Any] = []
+
+    def add_message_response(self, message_id: str, text: str, role: str = "agent") -> None:
+        """Add a mock Message response."""
+
+        # Create actual TextPart instance and wrap it in Part
+        text_part = Part(root=TextPart(text=text))
+
+        # Create actual Message instance
+        message = Message(
+            message_id=message_id, role=A2ARole.agent if role == "agent" else A2ARole.user, parts=[text_part]
+        )
+        self.responses.append(message)
+
+    def add_task_response(self, task_id: str, artifacts: list[dict[str, Any]]) -> None:
+        """Add a mock Task response."""
+        # Create mock artifacts
+        mock_artifacts = []
+        for artifact_data in artifacts:
+            # Create actual TextPart instance and wrap it in Part
+            text_part = Part(root=TextPart(text=artifact_data.get("content", "Test content")))
+
+            artifact = Artifact(
+                artifact_id=artifact_data.get("id", str(uuid4())),
+                name=artifact_data.get("name", "test-artifact"),
+                description=artifact_data.get("description", "Test artifact"),
+                parts=[text_part],
+            )
+            mock_artifacts.append(artifact)
+
+        # Create task status
+        status = TaskStatus(state=TaskState.completed, message=None)
+
+        # Create actual Task instance
+        task = Task(
+            id=task_id, context_id="test-context", status=status, artifacts=mock_artifacts if mock_artifacts else None
+        )
+
+        # Mock the ClientEvent tuple format
+        update_event = None  # No specific update event for completed tasks
+        client_event = (task, update_event)
+        self.responses.append(client_event)
+
+    async def send_message(self, message: Any) -> AsyncIterator[Any]:
+        """Mock send_message method that yields responses."""
+        self.call_count += 1
+
+        if self.responses:
+            response = self.responses.pop(0)
+            yield response
+
+
+@fixture
+def mock_a2a_client() -> MockA2AClient:
+    """Fixture that provides a mock A2A client."""
+    return MockA2AClient()
+
+
+@fixture
+def a2a_agent(mock_a2a_client: MockA2AClient) -> A2AAgent:
+    """Fixture that provides an A2AAgent with a mock client."""
+    return A2AAgent.model_construct(name="Test Agent", id="test-agent", client=mock_a2a_client, _http_client=None)
+
+
+def test_a2a_agent_initialization_with_client(mock_a2a_client: MockA2AClient) -> None:
+    """Test A2AAgent initialization with provided client."""
+    # Use model_construct to bypass Pydantic validation for mock objects
+    agent = A2AAgent.model_construct(
+        name="Test Agent", id="test-agent-123", description="A test agent", client=mock_a2a_client, _http_client=None
+    )
+
+    assert agent.name == "Test Agent"
+    assert agent.id == "test-agent-123"
+    assert agent.description == "A test agent"
+    assert agent.client == mock_a2a_client
+
+
+def test_a2a_agent_initialization_without_client_raises_error() -> None:
+    """Test A2AAgent initialization without client or URL raises ValueError."""
+    with raises(ValueError, match="Either agent_card or url must be provided"):
+        A2AAgent(name="Test Agent")
+
+
+async def test_run_with_message_response(a2a_agent: A2AAgent, mock_a2a_client: MockA2AClient) -> None:
+    """Test run() method with immediate Message response."""
+    mock_a2a_client.add_message_response("msg-123", "Hello from agent!", "agent")
+
+    response = await a2a_agent.run("Hello agent")
+
+    assert isinstance(response, AgentRunResponse)
+    assert len(response.messages) == 1
+    assert response.messages[0].role == Role.ASSISTANT
+    assert response.messages[0].text == "Hello from agent!"
+    assert response.response_id == "msg-123"
+    assert mock_a2a_client.call_count == 1
+
+
+async def test_run_with_task_response_single_artifact(a2a_agent: A2AAgent, mock_a2a_client: MockA2AClient) -> None:
+    """Test run() method with Task response containing single artifact."""
+    artifacts = [{"id": "art-1", "content": "Generated report content"}]
+    mock_a2a_client.add_task_response("task-456", artifacts)
+
+    response = await a2a_agent.run("Generate a report")
+
+    assert isinstance(response, AgentRunResponse)
+    assert len(response.messages) == 1
+    assert response.messages[0].role == Role.ASSISTANT
+    assert response.messages[0].text == "Generated report content"
+    assert response.response_id == "task-456"
+    assert mock_a2a_client.call_count == 1
+
+
+async def test_run_with_task_response_multiple_artifacts(a2a_agent: A2AAgent, mock_a2a_client: MockA2AClient) -> None:
+    """Test run() method with Task response containing multiple artifacts."""
+    artifacts = [
+        {"id": "art-1", "content": "First artifact content"},
+        {"id": "art-2", "content": "Second artifact content"},
+        {"id": "art-3", "content": "Third artifact content"},
+    ]
+    mock_a2a_client.add_task_response("task-789", artifacts)
+
+    response = await a2a_agent.run("Generate multiple outputs")
+
+    assert isinstance(response, AgentRunResponse)
+    assert len(response.messages) == 3
+
+    assert response.messages[0].text == "First artifact content"
+    assert response.messages[1].text == "Second artifact content"
+    assert response.messages[2].text == "Third artifact content"
+
+    # All should be assistant messages
+    for message in response.messages:
+        assert message.role == Role.ASSISTANT
+
+    assert response.response_id == "task-789"
+
+
+async def test_run_with_task_response_no_artifacts(a2a_agent: A2AAgent, mock_a2a_client: MockA2AClient) -> None:
+    """Test run() method with Task response containing no artifacts."""
+    mock_a2a_client.add_task_response("task-empty", [])
+
+    response = await a2a_agent.run("Do something with no output")
+
+    assert isinstance(response, AgentRunResponse)
+    assert response.response_id == "task-empty"
+
+
+async def test_run_with_unknown_response_type_raises_error(a2a_agent: A2AAgent, mock_a2a_client: MockA2AClient) -> None:
+    """Test run() method with unknown response type raises NotImplementedError."""
+    mock_a2a_client.responses.append("invalid_response")
+
+    with raises(NotImplementedError, match="Only Message and Task responses are supported"):
+        await a2a_agent.run("Test message")
+
+
+def test_task_to_chat_messages_empty_artifacts(a2a_agent: A2AAgent) -> None:
+    """Test _task_to_chat_messages with task containing no artifacts."""
+    task = MagicMock()
+    task.artifacts = None
+
+    result = a2a_agent._task_to_chat_messages(task)
+
+    assert len(result) == 0
+
+
+def test_task_to_chat_messages_with_artifacts(a2a_agent: A2AAgent) -> None:
+    """Test _task_to_chat_messages with task containing artifacts."""
+    task = MagicMock()
+
+    # Create mock artifacts
+    artifact1 = MagicMock()
+    artifact1.artifact_id = "art-1"
+    text_part1 = MagicMock()
+    text_part1.root = MagicMock()
+    text_part1.root.kind = "text"
+    text_part1.root.text = "Content 1"
+    text_part1.root.metadata = None
+    artifact1.parts = [text_part1]
+
+    artifact2 = MagicMock()
+    artifact2.artifact_id = "art-2"
+    text_part2 = MagicMock()
+    text_part2.root = MagicMock()
+    text_part2.root.kind = "text"
+    text_part2.root.text = "Content 2"
+    text_part2.root.metadata = None
+    artifact2.parts = [text_part2]
+
+    task.artifacts = [artifact1, artifact2]
+
+    result = a2a_agent._task_to_chat_messages(task)
+
+    assert len(result) == 2
+    assert result[0].text == "Content 1"
+    assert result[1].text == "Content 2"
+    assert all(msg.role == Role.ASSISTANT for msg in result)
+
+
+def test_artifact_to_chat_message(a2a_agent: A2AAgent) -> None:
+    """Test _artifact_to_chat_message conversion."""
+    artifact = MagicMock()
+    artifact.artifact_id = "test-artifact"
+
+    text_part = MagicMock()
+    text_part.root = MagicMock()
+    text_part.root.kind = "text"
+    text_part.root.text = "Artifact content"
+    text_part.root.metadata = None
+
+    artifact.parts = [text_part]
+
+    result = a2a_agent._artifact_to_chat_message(artifact)
+
+    assert isinstance(result, ChatMessage)
+    assert result.role == Role.ASSISTANT
+    assert result.text == "Artifact content"
+    assert result.raw_representation == artifact
+
+
+def test_get_uri_data_valid_uri() -> None:
+    """Test _get_uri_data with valid data URI."""
+
+    uri = "data:application/json;base64,eyJ0ZXN0IjoidmFsdWUifQ=="
+    result = _get_uri_data(uri)
+    assert result == "eyJ0ZXN0IjoidmFsdWUifQ=="
+
+
+def test_get_uri_data_invalid_uri() -> None:
+    """Test _get_uri_data with invalid URI format."""
+
+    with raises(ValueError, match="Invalid data URI format"):
+        _get_uri_data("not-a-valid-data-uri")
+
+
+def test_a2a_parts_to_contents_conversion(a2a_agent: A2AAgent) -> None:
+    """Test A2A parts to contents conversion."""
+
+    agent = A2AAgent.model_construct(name="Test Agent", client=MockA2AClient(), _http_client=None)
+
+    # Create A2A parts
+    parts = [Part(root=TextPart(text="First part")), Part(root=TextPart(text="Second part"))]
+
+    # Convert to contents
+    contents = agent._a2a_parts_to_contents(parts)
+
+    # Verify conversion
+    assert len(contents) == 2
+    assert isinstance(contents[0], TextContent)
+    assert isinstance(contents[1], TextContent)
+    assert contents[0].text == "First part"
+    assert contents[1].text == "Second part"
+
+
+def test_chat_message_to_a2a_message_with_error_content(a2a_agent: A2AAgent) -> None:
+    """Test _chat_message_to_a2a_message with ErrorContent."""
+
+    # Create ChatMessage with ErrorContent
+    error_content = ErrorContent(message="Test error message")
+    message = ChatMessage(role=Role.USER, contents=[error_content])
+
+    # Convert to A2A message
+    a2a_message = a2a_agent._chat_message_to_a2a_message(message)
+
+    # Verify conversion
+    assert len(a2a_message.parts) == 1
+    assert a2a_message.parts[0].root.text == "Test error message"
+
+
+def test_chat_message_to_a2a_message_with_uri_content(a2a_agent: A2AAgent) -> None:
+    """Test _chat_message_to_a2a_message with UriContent."""
+
+    # Create ChatMessage with UriContent
+    uri_content = UriContent(uri="http://example.com/file.pdf", media_type="application/pdf")
+    message = ChatMessage(role=Role.USER, contents=[uri_content])
+
+    # Convert to A2A message
+    a2a_message = a2a_agent._chat_message_to_a2a_message(message)
+
+    # Verify conversion
+    assert len(a2a_message.parts) == 1
+    assert a2a_message.parts[0].root.file.uri == "http://example.com/file.pdf"
+    assert a2a_message.parts[0].root.file.mime_type == "application/pdf"
+
+
+def test_chat_message_to_a2a_message_with_data_content(a2a_agent: A2AAgent) -> None:
+    """Test _chat_message_to_a2a_message with DataContent."""
+
+    # Create ChatMessage with DataContent (base64 data URI)
+    data_content = DataContent(uri="data:text/plain;base64,SGVsbG8gV29ybGQ=", media_type="text/plain")
+    message = ChatMessage(role=Role.USER, contents=[data_content])
+
+    # Convert to A2A message
+    a2a_message = a2a_agent._chat_message_to_a2a_message(message)
+
+    # Verify conversion
+    assert len(a2a_message.parts) == 1
+    assert a2a_message.parts[0].root.file.bytes == "SGVsbG8gV29ybGQ="
+    assert a2a_message.parts[0].root.file.mime_type == "text/plain"
+
+
+def test_chat_message_to_a2a_message_empty_contents_raises_error(a2a_agent: A2AAgent) -> None:
+    """Test _chat_message_to_a2a_message with empty contents raises ValueError."""
+    # Create ChatMessage with no contents
+    message = ChatMessage(role=Role.USER, contents=[])
+
+    # Should raise ValueError for empty contents
+    with raises(ValueError, match="ChatMessage.contents is empty"):
+        a2a_agent._chat_message_to_a2a_message(message)
+
+
+async def test_run_stream_with_message_response(a2a_agent: A2AAgent, mock_a2a_client: MockA2AClient) -> None:
+    """Test run_stream() method with immediate Message response."""
+    mock_a2a_client.add_message_response("msg-stream-123", "Streaming response from agent!", "agent")
+
+    # Collect streaming updates
+    updates: list[AgentRunResponseUpdate] = []
+    async for update in a2a_agent.run_stream("Hello agent"):
+        updates.append(update)
+
+    # Verify streaming response
+    assert len(updates) == 1
+    assert isinstance(updates[0], AgentRunResponseUpdate)
+    assert updates[0].role == Role.ASSISTANT
+    assert len(updates[0].contents) == 1
+
+    content = updates[0].contents[0]
+    assert isinstance(content, TextContent)
+    assert content.text == "Streaming response from agent!"
+
+    assert updates[0].response_id == "msg-stream-123"
+    assert mock_a2a_client.call_count == 1
+
+
+async def test_context_manager_cleanup() -> None:
+    """Test context manager cleanup of http client."""
+
+    # Create mock http client that tracks aclose calls
+    mock_http_client = AsyncMock()
+    mock_a2a_client = MagicMock()
+
+    agent = A2AAgent.model_construct(client=mock_a2a_client, _http_client=mock_http_client)
+
+    # Test context manager cleanup
+    async with agent:
+        pass
+
+    # Verify aclose was called
+    mock_http_client.aclose.assert_called_once()
+
+
+async def test_context_manager_no_cleanup_when_no_http_client() -> None:
+    """Test context manager when _http_client is None."""
+
+    mock_a2a_client = MagicMock()
+
+    agent = A2AAgent.model_construct(client=mock_a2a_client, _http_client=None)
+
+    # This should not raise any errors
+    async with agent:
+        pass
+
+
+def test_chat_message_to_a2a_message_with_multiple_contents() -> None:
+    """Test conversion of ChatMessage with multiple contents."""
+
+    agent = A2AAgent.model_construct(client=MagicMock(), _http_client=None)
+
+    # Create message with multiple content types
+    message = ChatMessage(
+        role=Role.USER,
+        contents=[
+            TextContent(text="Here's the analysis:"),
+            DataContent(data=b"binary data", media_type="application/octet-stream"),
+            UriContent(uri="https://example.com/image.png", media_type="image/png"),
+            TextContent(text='{"structured": "data"}'),
+        ],
+    )
+
+    result = agent._chat_message_to_a2a_message(message)
+
+    # Should have converted all 4 contents to parts
+    assert len(result.parts) == 4
+
+    # Check each part type
+    assert result.parts[0].root.kind == "text"  # Regular text
+    assert result.parts[1].root.kind == "file"  # Binary data
+    assert result.parts[2].root.kind == "file"  # URI content
+    assert result.parts[3].root.kind == "text"  # JSON text remains as text (no parsing)
+
+
+def test_a2a_parts_to_contents_with_data_part() -> None:
+    """Test conversion of A2A DataPart."""
+
+    agent = A2AAgent.model_construct(client=MagicMock(), _http_client=None)
+
+    # Create DataPart
+    data_part = Part(root=DataPart(data={"key": "value", "number": 42}, metadata={"source": "test"}))
+
+    contents = agent._a2a_parts_to_contents([data_part])
+
+    assert len(contents) == 1
+
+    assert isinstance(contents[0], TextContent)
+    assert contents[0].text == '{"key": "value", "number": 42}'
+    assert contents[0].additional_properties == {"source": "test"}
+
+
+def test_a2a_parts_to_contents_unknown_part_kind() -> None:
+    """Test error handling for unknown A2A part kind."""
+    agent = A2AAgent.model_construct(client=MagicMock(), _http_client=None)
+
+    # Create a mock part with unknown kind
+    mock_part = MagicMock()
+    mock_part.root.kind = "unknown_kind"
+
+    with raises(ValueError, match="Unknown Part kind: unknown_kind"):
+        agent._a2a_parts_to_contents([mock_part])
+
+
+def test_chat_message_to_a2a_message_with_hosted_file() -> None:
+    """Test conversion of ChatMessage with HostedFileContent to A2A message."""
+
+    agent = A2AAgent.model_construct(client=MagicMock(), _http_client=None)
+
+    # Create message with hosted file content
+    message = ChatMessage(
+        role=Role.USER,
+        contents=[HostedFileContent(file_id="hosted://storage/document.pdf")],
+    )
+
+    result = agent._chat_message_to_a2a_message(message)  # noqa: SLF001
+
+    # Verify the conversion
+    assert len(result.parts) == 1
+    part = result.parts[0]
+    assert part.root.kind == "file"
+
+    # Verify it's a FilePart with FileWithUri
+
+    assert isinstance(part.root, FilePart)
+    assert isinstance(part.root.file, FileWithUri)
+    assert part.root.file.uri == "hosted://storage/document.pdf"
+    assert part.root.file.mime_type is None  # HostedFileContent doesn't specify media_type
+
+
+def test_a2a_parts_to_contents_with_hosted_file_uri() -> None:
+    """Test conversion of A2A FilePart with hosted file URI back to UriContent."""
+
+    agent = A2AAgent.model_construct(client=MagicMock(), _http_client=None)
+
+    # Create FilePart with hosted file URI (simulating what A2A would send back)
+    file_part = Part(
+        root=FilePart(
+            file=FileWithUri(
+                uri="hosted://storage/document.pdf",
+                mime_type=None,
+            )
+        )
+    )
+
+    contents = agent._a2a_parts_to_contents([file_part])  # noqa: SLF001
+
+    assert len(contents) == 1
+
+    assert isinstance(contents[0], UriContent)
+    assert contents[0].uri == "hosted://storage/document.pdf"
+    assert contents[0].media_type == ""  # Converted None to empty string
@@ -0,0 +1,24 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+import importlib
+from typing import Any
+
+PACKAGE_NAME = "agent_framework_a2a"
+PACKAGE_EXTRA = "a2a"
+_IMPORTS = ["__version__", "A2AAgent"]
+
+
+def __getattr__(name: str) -> Any:
+    if name in _IMPORTS:
+        try:
+            return getattr(importlib.import_module(PACKAGE_NAME), name)
+        except ModuleNotFoundError as exc:
+            raise ModuleNotFoundError(
+                f"The '{PACKAGE_EXTRA}' extra is not installed, "
+                f"please do `pip install agent-framework[{PACKAGE_EXTRA}]`"
+            ) from exc
+    raise AttributeError(f"Module {PACKAGE_NAME} has no attribute {name}.")
+
+
+def __dir__() -> list[str]:
+    return _IMPORTS
@@ -0,0 +1,5 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+from agent_framework_a2a import A2AAgent, __version__
+
+__all__ = ["A2AAgent", "__version__"]
@@ -35,7 +35,7 @@ dependencies = [
    "opentelemetry-exporter-otlp-proto-grpc>=1.36.0",
    "opentelemetry-semantic-conventions-ai>=0.4.13",
    "aiofiles>=24.1.0",
-    "azure-identity>=1,<2"
+    "azure-identity>=1,<2",
 ]

 [project.optional-dependencies]
@@ -63,6 +63,9 @@ runtime = [
 mem0 = [
    "agent-framework-mem0"
 ]
+a2a = [
+    "agent-framework-a2a"
+]
 devui = [
    "agent-framework-devui"
 ]
@@ -71,6 +74,7 @@ all = [
    "agent-framework-azure-ai",
    "agent-framework-runtime",
    "agent-framework-mem0",
+    "agent-framework-a2a",
    "agent-framework-redis",
    "agent-framework-devui",
    "graphviz>=0.20.0"
@@ -91,6 +95,7 @@ fallback-version = "0.0.0"
 testpaths = [
    'tests',
    'packages/main/tests',
+    'packages/a2a/tests',
    'packages/azure-ai/tests',
    'packages/copilotstudio/tests',
    'packages/mem0/tests',