Files
agent-framework/python/packages/core
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 · 2026-05-05 10:06:16 +00:00
History
..
2025-09-30 07:18:36 +00:00

Get Started with Microsoft Agent Framework

Highlights

  • Flexible Agent Framework: build, orchestrate, and deploy AI agents and multi-agent systems
  • Multi-Agent Orchestration: Group chat, sequential, concurrent, and handoff patterns
  • Plugin Ecosystem: Extend with native functions, OpenAPI, Model Context Protocol (MCP), and more
  • LLM Support: OpenAI, Foundry, Anthropic, and more
  • Runtime Support: In-process and distributed agent execution
  • Multimodal: Text, vision, and function calling
  • Cross-Platform: .NET and Python implementations

Quick Install

pip install agent-framework-core
# Optional: Add Azure AI Foundry integration
pip install agent-framework-foundry
# Optional: Add OpenAI integration
pip install agent-framework-openai

Supported Platforms:

  • Python: 3.10+
  • OS: Windows, macOS, Linux

1. Setup API Keys

Depending on the client you want to use, there are various environment variables you can set to configure the chat clients. This can be done in the environment itself, or with a .env file in your project root, some examples of environment variables include:

FOUNDRY_PROJECT_ENDPOINT=...
FOUNDRY_MODEL=...
...
OPENAI_API_KEY=sk-...
OPENAI_CHAT_COMPLETION_MODEL=...
OPENAI_CHAT_MODEL=...
...
AZURE_OPENAI_API_KEY=...
AZURE_OPENAI_ENDPOINT=...
AZURE_OPENAI_MODEL=...

You can also override environment variables by explicitly passing configuration parameters to the chat client constructor:

from agent_framework.openai import OpenAIChatClient

client = OpenAIChatClient(
    api_key="",
    model="",
)

See the following getting started samples for more information.

2. Create a Simple Agent

Create agents and invoke them directly:

import asyncio
from agent_framework import Agent
from agent_framework.openai import OpenAIChatClient

agent = Agent(
    client=OpenAIChatClient(),
    instructions="""
    1) A robot may not injure a human being...
    2) A robot must obey orders given it by human beings...
    3) A robot must protect its own existence...

    Give me the TLDR in exactly 5 words.
    """
)

result = asyncio.run(agent.run("Summarize the Three Laws of Robotics"))
print(result)
# Output: Protect humans, obey, self-preserve, prioritized.

3. Directly Use Chat Clients (No Agent Required)

You can use the chat client classes directly for advanced workflows:

import asyncio
from agent_framework.openai import OpenAIChatClient
from agent_framework import Message, Role

async def main():
    client = OpenAIChatClient()

    response = await client.get_response([
        Message("system", ["You are a helpful assistant."]),
        Message("user", ["Write a haiku about Agent Framework."])
    ])
    print(response.messages[0].text)

    """
    Output:

    Agents work in sync,
    Framework threads through each task—
    Code sparks collaboration.
    """

asyncio.run(main())

4. Build an Agent with Tools and Functions

Enhance your agent with custom tools and function calling:

import asyncio
from typing import Annotated
from random import randint
from agent_framework import Agent
from agent_framework.openai import OpenAIChatClient


def get_weather(
    location: Annotated[str, "The location to get the weather for."],
) -> str:
    """Get the weather for a given location."""
    conditions = ["sunny", "cloudy", "rainy", "stormy"]
    return f"The weather in {location} is {conditions[randint(0, 3)]} with a high of {randint(10, 30)}°C."


def get_menu_specials() -> str:
    """Get today's menu specials."""
    return """
    Special Soup: Clam Chowder
    Special Salad: Cobb Salad
    Special Drink: Chai Tea
    """


async def main():
    agent = Agent(
        client=OpenAIChatClient(),
        instructions="You are a helpful assistant that can provide weather and restaurant information.",
        tools=[get_weather, get_menu_specials]
    )

    response = await agent.run("What's the weather in Amsterdam and what are today's specials?")
    print(response)

    # Output:
    # The weather in Amsterdam is sunny with a high of 22°C. Today's specials include
    # Clam Chowder soup, Cobb Salad, and Chai Tea as the special drink.

asyncio.run(main())

You can explore additional agent samples here.

5. Multi-Agent Orchestration

Coordinate multiple agents to collaborate on complex tasks using orchestration patterns:

import asyncio
from agent_framework import Agent
from agent_framework.openai import OpenAIChatClient


async def main():
    # Create specialized agents
    writer = Agent(
        client=OpenAIChatClient(),
        name="Writer",
        instructions="You are a creative content writer. Generate and refine slogans based on feedback."
    )

    reviewer = Agent(
        client=OpenAIChatClient(),
        name="Reviewer",
        instructions="You are a critical reviewer. Provide detailed feedback on proposed slogans."
    )

    # Sequential workflow: Writer creates, Reviewer provides feedback
    task = "Create a slogan for a new electric SUV that is affordable and fun to drive."

    # Step 1: Writer creates initial slogan
    initial_result = await writer.run(task)
    print(f"Writer: {initial_result}")

    # Step 2: Reviewer provides feedback
    feedback_request = f"Please review this slogan: {initial_result}"
    feedback = await reviewer.run(feedback_request)
    print(f"Reviewer: {feedback}")

    # Step 3: Writer refines based on feedback
    refinement_request = f"Please refine this slogan based on the feedback: {initial_result}\nFeedback: {feedback}"
    final_result = await writer.run(refinement_request)
    print(f"Final Slogan: {final_result}")

    # Example Output:
    # Writer: "Charge Forward: Affordable Adventure Awaits!"
    # Reviewer: "Good energy, but 'Charge Forward' is overused in EV marketing..."
    # Final Slogan: "Power Up Your Adventure: Premium Feel, Smart Price!"

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

Note: Sequential, Concurrent, Group Chat, Handoff, and Magentic orchestrations are available. See examples in orchestration samples.

More Examples & Samples

Agent Framework Documentation