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agent-framework/python/samples/04-hosting/foundry-hosted-agents
T
Eduard van Valkenburg 57c901a245 Python: Fix hyperlight WasmSandbox cross-thread Drop and harden hosted-agent sample (#5603)
* update hyperlight to beta and move samples, add hosted agent sample

* Python: Fix hyperlight WasmSandbox cross-thread Drop and harden sample

Root cause: when a worker-side closure raised, the exception's __traceback__
retained frame locals that included the partially constructed PyO3 sandbox.
Future.result() re-raised that exception on the caller thread, and when the
caller's exception was eventually GC'd the frame locals were released
off-thread, dec_ref'ing the unsendable sandbox from the wrong thread and
tripping the PyO3 panic
'_native_wasm::WasmSandbox is unsendable, but is being dropped on another thread'.

Fix:
* Add _SandboxWorker._run_on_worker which catches every exception on the
  worker, drops __traceback__ there, deletes the original exception, and
  re-raises a fresh instance on the caller thread. initialize and execute
  route through it; dispose keeps its bare-submit semantics.
* Add an opt-in diagnostic module _drop_diagnostic (no-op unless
  HYPERLIGHT_TRACE_DROPS=1) that installs a sys.unraisablehook and dumps
  owner-thread + per-thread stacks on any future cross-thread unsendable
  Drop. Useful for triaging similar PyO3 regressions.
* Tests: cross-thread invocation, traceback-leak isolation, _SandboxEntry
  attribute-shape check, and a stale-reference stress test driven through
  asyncio.to_thread.

Sample (samples/04-hosting/foundry-hosted-agents/responses/06_hyperlight_codeact):
* Dockerfile installs agent-framework-* from in-tree source with python/ as
  build context so unreleased fixes can be validated end-to-end.
* call_server.py pins the Responses API version.
* main.py enables include_detailed_errors=True so future tool failures
  surface the actual exception text instead of a bare 'Error: Function
  failed.' string.
* README.md documents the in-tree-package build and the Hyperlight
  hypervisor requirement (/dev/kvm on Linux, MSHV on Windows). Hosted
  environments without hypervisor passthrough surface 'No Hypervisor was
  found for Sandbox'; this is a hosting constraint, not a hyperlight bug.

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

* Python: remove _drop_diagnostic from hyperlight package

The diagnostic module was useful while bisecting the cross-thread Drop bug,
but it is no longer needed now that _SandboxWorker._run_on_worker prevents
the panic at the source.

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

* Python: address PR review feedback on hyperlight

- Use lazy agent_framework.hyperlight import in sample main.py.
- Env-driven endpoint (FOUNDRY_AGENT_ENDPOINT) in call_server.py; remove personal URLs.
- Align agent.yaml model deployment with manifest (gpt-4.1-mini).
- Tighten Dockerfile requirements guard; drop dangling deploy.ps1 reference.
- Preserve exception args when sanitizing tracebacks in _run_on_worker.
- Add public _SandboxWorker.is_alive(); update test to avoid private attr.
- Add namespace coverage tests for agent_framework.hyperlight lazy loader.
- Add prominent note: Foundry hosted-agent runtime does not yet support
  Hyperlight (no hypervisor exposed); container works locally with /dev/kvm.

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

* Python: bump hyperlight-sandbox dependencies to 0.4.x

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

* Python: renumber hyperlight codeact sample to 08

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

* Coerce worker exception args to strings for cross-thread safety

Stringify exc.args on the worker thread before propagating, so any
PyO3 unsendable object captured in args (e.g. via a caller-supplied
callback or underlying SDK) cannot be Dropped on the calling thread.

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

* moved sample

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
57c901a245 ยท 2026-05-05 10:06:16 +00:00
History
..

Foundry Hosted Agent Samples

This directory contains samples that demonstrate how to use hosted Agent Framework agents with different capabilities and configurations on Foundry using the Foundry Hosting Agent service. Each sample includes a README with instructions on how to set up, run, and interact with the agent.

Samples

Responses API

# Sample Description
1 Basic A minimal agent demonstrating basic request/response interaction and multi-turn conversations using previous_response_id.
2 Tools An agent with local tools (e.g., weather lookup), demonstrating how to register and invoke custom tool functions alongside the LLM.
3 MCP An agent connected to a remote MCP server (GitHub), demonstrating external MCP tool provider integration.
4 Foundry Toolbox An agent using Azure Foundry Toolbox, demonstrating toolbox provisioning and querying available tools at runtime.
5 Workflows An agent with a multi-step orchestrated workflow, demonstrating chaining prompts through an orchestrated flow.
6 Files An agent demonstrating how to work with files in a hosted agent session, including uploading files to a hosted agent session and having the agent read and manipulate those files at runtime.
7 Observability A sample demonstrating how to enable observability for the agent deployed to Foundry.
8 Using deployed agent A sample demonstrating how to invoke an agent that has already been deployed to Foundry, showing how to interact with a hosted agent in code.

Invocations API

# Sample Description
1 Basic A minimal agent demonstrating session state management via agent_session_id in URL params/response headers.
2 Break Glass An agent demonstrating a "break glass" scenario where customizations of the API behaviors are needed, allowing for more direct control over how requests and responses are handled by the hosting layer.

Running the Agent Host Locally

Using azd

Prerequisites

  1. Azure Developer CLI (azd)

    • Install azd and the AI agent extension: azd ext install azure.ai.agents
    • Authenticated: azd auth login
  2. Azure Subscription

Create a new project

No cloning required. Create a new folder, point azd at the manifest on GitHub.

mkdir hosted-agent-framework-agent && cd hosted-agent-framework-agent

# Initialize from the manifest
azd ai agent init -m https://github.com/microsoft/agent-framework/blob/main/python/samples/04-hosting/foundry-hosted-agents/responses/01_basic/agent.manifest.yaml

Follow the instructions from azd ai agent init to complete the agent initialization. If you don't have an existing Foundry project and a model deployment, azd ai agent init will guide you through creating them.

Provision Azure Resources

This step is only needed if you don't have an existing Foundry project and model deployment.

Run the following command to provision the necessary Azure resources:

azd provision

This will create the following Azure resources:

  • A new resource group named rg-[project_name]-dev. In this guide, [project_name] will be hosted-agent-framework-agent.
  • Within the resource group, among other resources, the most important ones are:
    • A new Foundry instance
    • A new Foundry project, within which a new model deployment will be created
    • An Application Insights instance
    • A container registry, which will be used to store the container images for the hosted agent

Set Environment Variables

export FOUNDRY_PROJECT_ENDPOINT="https://<account>.services.ai.azure.com/api/projects/<project>"
export AZURE_AI_MODEL_DEPLOYMENT_NAME="<your-model-deployment-name>"
# And any other environment variables required by the sample

Or in PowerShell:

$env:FOUNDRY_PROJECT_ENDPOINT="https://<account>.services.ai.azure.com/api/projects/<project>"
$env:AZURE_AI_MODEL_DEPLOYMENT_NAME="<your-model-deployment-name>"
# And any other environment variables required by the sample

Note: The environment variables set above are only for the current session. You will need to set them again if you open a new terminal session. if you want to set the environment variables permanently in the azd environment, you can use azd env set <name> <value>.

Running the Agent Host

azd ai agent run

Right now, the agent host should be running on http://localhost:8088

Invoking the Agent

Open another terminal, navigate to the project directory, and run the following command to invoke the agent:

azd ai agent invoke --local "Hello!"

Or you can in another terminal, without navigating to the project directory, run the following command to invoke the agent:

curl -X POST http://localhost:8088/responses -H "Content-Type: application/json" -d '{"input": "Hello!"}'

Or in PowerShell:

(Invoke-WebRequest -Uri http://localhost:8088/responses -Method POST -ContentType "application/json" -Body '{"input": "Hello!"}').Content

Using python

Prerequisites

  1. An existing Foundry project
  2. A deployed model in your Foundry project
  3. Azure CLI installed and authenticated
  4. Python 3.10 or later

Running the Agent Host with Python

Clone the repository containing the sample code:

git clone https://github.com/microsoft/agent-framework.git
cd agent-framework/python/samples/04-hosting/foundry-hosted-agents/responses

Environment setup

  1. Navigate to the sample directory you want to explore. Create and activate a virtual environment using uv (recommended):

    uv venv .venv
    
    # Windows (PowerShell)
    .venv\Scripts\Activate.ps1
    
    # Windows (Command Prompt)
    .venv\Scripts\activate.bat
    
    # macOS/Linux
    source .venv/bin/activate
    

    Note: python -m venv .venv also works, but can hang indefinitely on Windows with Microsoft Store Python due to a known ensurepip issue. Use uv venv .venv to avoid this.

  2. Install dependencies:

    pip install -r requirements.txt
    
  3. Create a .env file with your Foundry configuration following the env.example file in the sample.

  4. Make sure you are logged in with the Azure CLI:

    az login
    

Running the Agent Host

python main.py

Right now, the agent host should be running on http://localhost:8088

Invoking the Agent

On another terminal, run the following command to invoke the agent:

curl -X POST http://localhost:8088/responses -H "Content-Type: application/json" -d '{"input": "Hello!"}'

Or in PowerShell:

(Invoke-WebRequest -Uri http://localhost:8088/responses -Method POST -ContentType "application/json" -Body '{"input": "Hello!"}').Content

Deploying the Agent to Foundry

Once you've tested locally, deploy to Microsoft Foundry.

With an Existing Foundry Project

If you already have a Foundry project and the necessary Azure resources provisioned, you can skip the setup steps and proceed directly to deploying the agent.

After running azd ai agent init -m <agent.manifest.yaml> and following the prompts to configure your agent, you will have a project ready for deployment.

Setting Up a New Foundry Project

Follow the steps in Using azd to set up the project and provision the necessary Azure resources for your Foundry deployment.

Deploying the Agent

Once the project is setup and resources are provisioned, you can deploy the agent to Foundry by running:

azd deploy

The Foundry hosting infrastructure will inject the following environment variables into your agent at runtime:

  • FOUNDRY_PROJECT_ENDPOINT: The endpoint URL for the Foundry project where the agent is deployed.
  • AZURE_AI_MODEL_DEPLOYMENT_NAME: The name of the model deployment in your Foundry project. This is configured during the agent initialization process with azd ai agent init.
  • APPLICATIONINSIGHTS_CONNECTION_STRING: The connection string for Application Insights to enable telemetry for your agent.

This will package your agent and deploy it to the Foundry environment, making it accessible through the Foundry project endpoint. Once it's deployed, you can also access the agent through the Foundry UI.

For the full deployment guide, see the official deployment guide.

Once deployed, learn more about how to manage deployed agents in the official management guide.