* Bump MEAI to 10.5.1 and add per-call x-client header support
Replaces the brittle UserAgentResponsesClient subclass with a clean
per-call x-client-* header pipeline built on the new Microsoft.Extensions.AI
10.5.1 OpenAIRequestPolicies hook.
Public surface (Microsoft.Agents.AI.Foundry, [Experimental(MAAI001)]):
* chatOptions.WithClientHeader(name, value) and .WithClientHeaders(IEnumerable)
validate the x-client- prefix (case-insensitive), apply all-or-nothing on
bulk, and throw InvalidOperationException on foreign-typed slot collision
* myAgent.AsBuilder().UseClientHeaders().Build() opts a customer-built agent
into the pipeline; idempotent via agent.GetService<ClientHeadersAgent>()
* Foundry-built agents (FoundryAgent.Create*) pre-wire automatically
Internals:
* ClientHeadersAgent decorator snapshots the dict at scope-push time so
concurrent runs sharing a ChatOptions reference do not leak headers
* ClientHeadersScope is an AsyncLocal<IReadOnlyDictionary<string,string>?>
with LIFO push/dispose semantics
* ClientHeadersPolicy singleton stamps headers via Headers.Set so per-call
values overwrite any same-name header from earlier policies and so
duplicate registration is value-stable
* OpenAIRequestPoliciesReflection dedups against MEAI's private _entries
field and falls back to AddPolicy on any reflection failure; a CI test
asserts the field shape on every MEAI bump
Hosting cleanup:
* Deleted UserAgentResponsesClient and its dummy throwing pipeline
* HostedAgentUserAgentPolicy is now registered via OpenAIRequestPolicies
in FoundryHostingExtensions.TryApplyUserAgent
Tests:
* 19 new unit tests in ClientHeadersExtensionsTests.cs covering validation,
AsyncLocal isolation, snapshot semantics, end-to-end wire stamping, and
shared-chat-client dedup
* Updated OpenTelemetryAgentTests for MEAI 10.5.1 changes to web_search
serialization and the reduced tool definition payload when sensitive
data capture is disabled
Microsoft.Extensions.Compliance.Abstractions stays at 10.5.0 because no
10.5.1 release exists on nuget.org.
* Address PR review: pre-wire AsAIAgent path and dedup TryApplyUserAgent
* FoundryAgent: extract WireClientHeaders helper and call it from the
internal (AIProjectClient, ChatClientAgent) constructor used by
AzureAIProjectChatClientExtensions.AsAIAgent so those Foundry-built
agents also pre-wire the x-client header pipeline.
* Foundry.Hosting TryApplyUserAgent: dedup HostedAgentUserAgentPolicy
registration per OpenAIRequestPolicies instance via
ConditionalWeakTable so per-request resolution does not grow the
policy list unboundedly on singleton agents.
* Add tests covering AsAIAgent pre-wire and TryApplyUserAgent dedup
Backs the PR review fixes from a4c8f91 with regression tests:
* ClientHeadersExtensionsTests: AsAIAgent_FoundryAgent_HasPreWiredClientHeadersAgent
asserts the FoundryAgent built via AzureAIProjectChatClientExtensions.AsAIAgent
contains a ClientHeadersAgent in its delegating chain (catches future
regressions of the bypass).
* ClientHeadersExtensionsTests: FoundryAgent_PublicConstructor_HasPreWiredClientHeadersAgent
covers the public constructor path the same way.
* ClientHeadersExtensionsTests: UseClientHeaders_RepeatedRegistrations_OnSameChatClient_OnlyRegistersOnce
invokes UseClientHeaders 25 times on a shared chat client and asserts via
reflection that OpenAIRequestPolicies._entries length is exactly 1.
* HostedTryApplyUserAgentDedupTests: two tests asserting
FoundryHostingExtensions.TryApplyUserAgent stays at one entry per
OpenAIRequestPolicies instance after 50 calls on the same agent and across
distinct agents on different chat clients.
* Move tests next to their SUT
Removes the dedicated HostedTryApplyUserAgentDedupTests.cs test class.
Tests are co-located with the SUT they exercise:
* FoundryAgentTests.cs gains the Constructor_PreWiresClientHeadersAgent
and Constructor_FromAsAIAgentExtension_PreWiresClientHeadersAgent
cases, since FoundryAgent is the SUT for the pre-wire behavior.
* HostedOutboundUserAgentTests.cs gains the two TryApplyUserAgent dedup
cases, since FoundryHostingExtensions.TryApplyUserAgent is the SUT
it already covers.
* ClientHeadersExtensionsTests.cs keeps only the
UseClientHeaders_RepeatedRegistrations_OnSameChatClient_OnlyRegistersOnce
case, which exercises the public ClientHeadersExtensions surface.
* Remove redundant WithCancellation on inner streaming call
ct is already passed to InnerAgent.RunStreamingAsync, so
.WithCancellation(ct) on the resulting IAsyncEnumerable is a no-op.
Caught by Sergey on PR review.
* Address PR review: surface downstream MEAI experimental ID
* Add AIOpenAIRequestPolicies = MEAIExperiments alias to
DiagnosticIds.Experiments (matches the existing AIResponseContinuations,
AIMcpServers, AIFunctionApprovals pattern).
* Mark public ClientHeadersExtensions with [Experimental(AIOpenAIRequestPolicies)]
instead of AgentsAIExperiments. Consumers now see the MEAI001 warning,
surfacing the dependency on MEAI's experimental OpenAIRequestPolicies hook.
* Mark internal OpenAIRequestPoliciesReflection with the same alias to
suppress warnings at the source rather than via project-wide NoWarn.
* Remove MEAI001 from Foundry csproj NoWarn (kept on Foundry.Hosting where
pre-PR usages remain).
* Clarify ClientHeadersScope XML doc: AsyncLocal flows values forward but
does NOT auto-restore on method return; explicit using/Dispose is what
gives stack-style LIFO semantics.
Welcome to Microsoft Agent Framework!
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)
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
- Overview - High level overview of the framework
- Quick Start - Get started with a simple agent
- Tutorials - Step by step tutorials
- User Guide - In-depth user guide for building agents and workflows
- Migration from Semantic Kernel - Guide to migrate from Semantic Kernel
- Migration from AutoGen - Guide to migrate from AutoGen
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
- Getting Started: progressive tutorial from hello agent to hosting
- Agent Concepts: basic agent creation and tool usage
- Agent Providers: samples showing different agent providers
- Workflows: advanced multi-agent patterns and workflow orchestration
- Hosting: A2A, Durable Agents, Durable Workflows
- End-to-End: full applications and demos
Community & Feedback
- Found a bug? File a GitHub issue to help us improve.
- Enjoying MAF?
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:
DefaultAzureCredentialis 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 organization’s 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
