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agent-framework/python
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Eduard van Valkenburg 66a09a76af Python: fix: hyperlight skips symlinks when staging sandbox input (#5919)
* Python: fix(hyperlight): skip symlinks when staging files into the sandbox

The helpers that populate the sandbox input tree (``_copy_path`` and the
``_path_tree_signature`` walker used for cache invalidation) relied on
``Path.is_file()``, ``Path.is_dir()`` and ``shutil.copy2`` - all of which
follow symlinks by default. When the source tree contains symlinks, that
let entries from outside the configured input source surface inside the
sandbox.

Harden both code paths to never follow symlinks:

- ``_copy_path`` now bails out via ``Path.is_symlink()`` before any
  ``is_dir()`` / ``is_file()`` check, skips non-regular files, and uses
  ``shutil.copy2(..., follow_symlinks=False)`` as defense in depth.
- New ``_iter_real_entries`` walker replaces the previous ``Path.rglob``
  call inside ``_path_tree_signature`` (rglob follows directory symlinks).
- ``_path_tree_signature`` switches to ``Path.lstat()`` so size/mtime are
  never read through a symlink target.

Added regression tests covering:

- A pre-placed file symlink in ``workspace_root`` (top level).
- A pre-placed directory symlink in ``workspace_root``.
- A nested file symlink inside a real subdirectory.
- ``_path_tree_signature`` ignoring symlinks so the cache key reflects only
  what is actually staged.

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

* Python: fix(hyperlight): address PR #5919 review feedback

- _iter_real_entries now yields directories and regular files only,
  skipping non-regular entries (sockets/FIFOs/devices). Keeps the
  cache-key signature consistent with what _copy_path actually stages.
- The four new symlink regression tests skip when the platform does not
  support symlink creation (e.g. unprivileged Windows runners), via a
  local _symlinks_supported helper modelled on the one in
  packages/core/tests/core/test_skills.py. Prevents OSError /
  NotImplementedError from failing CI jobs that have nothing to do with
  the change under test.

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

* Python: fix(hyperlight): address PR #5919 follow-up review feedback

- _copy_path docstring: narrow the scope to "symlink entries present in
  the source tree at rest" and explicitly call out that the copy is NOT
  atomic with respect to concurrent mutation of the source tree.
  Callers who need that stronger guarantee should snapshot their
  workspace before passing it in. Avoids overpromising on a TOCTOU
  window that pathlib cannot express; closing it properly would need
  fd-based traversal (O_NOFOLLOW | O_DIRECTORY + os.scandir(fd)) with
  a separate Windows story, which is out of scope for this targeted
  fix.

- _path_tree_signature: drop the `if path.is_symlink(): return ()`
  short-circuit. Resolve a symlink root to its real target before
  walking instead. The public construction flow already resolves
  workspace_root / file_mounts[].host_path up front so this never
  affected user-facing code, but the short-circuit was misleading and
  would have produced an empty, stable signature for any direct
  caller that builds a _RunConfig without going through the public
  constructor. Defense in depth: even if a future call site forgets
  to resolve the root, the cache key still reflects real contents.

- Added regression test
  test_path_tree_signature_walks_through_symlinked_root: a symlinked
  workspace root must produce a non-empty signature, AND the signature
  must change when the real target's contents change so the cache key
  actually invalidates.

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

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
66a09a76af · 2026-05-19 11:41:53 +00:00
History
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2025-10-01 11:54:26 +00:00

Get Started with Microsoft Agent Framework for Python Developers

Quick Install

We recommend two common installation paths depending on your use case.

1. Development mode

If you are exploring or developing locally, install the entire framework with all sub-packages:

pip install agent-framework

This installs the core and every integration package, making sure that all features are available without additional steps. This is the simplest way to get started.

2. Selective install

If you only need specific integrations, you can install at a more granular level. This keeps dependencies lighter and focuses on what you actually plan to use. Some examples:

# Core only
# includes Azure OpenAI and OpenAI support by default
# also includes workflows and orchestrations
pip install agent-framework-core

# Core + Azure AI Foundry integration
pip install agent-framework-foundry

# Core + Microsoft Copilot Studio integration (preview package)
pip install agent-framework-copilotstudio --pre

# Core + both Microsoft Copilot Studio and Azure AI Foundry integration
pip install --pre agent-framework-copilotstudio agent-framework-foundry

This selective approach is useful when you know which integrations you need, and it is the recommended way to set up lightweight environments. Released packages such as agent-framework, agent-framework-core, and agent-framework-foundry no longer require --pre, while preview connectors such as agent-framework-copilotstudio still do.

Supported Platforms:

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

1. Setup API Keys

Set as environment variables, or create a .env file at your project root:

OPENAI_API_KEY=sk-...
OPENAI_MODEL=...
...
AZURE_OPENAI_API_KEY=...
AZURE_OPENAI_ENDPOINT=...
AZURE_OPENAI_MODEL=...
...
FOUNDRY_PROJECT_ENDPOINT=...
FOUNDRY_MODEL=...

For the generic OpenAI clients (OpenAIChatClient and OpenAIChatCompletionClient), configuration resolves in this order:

  1. Explicit Azure inputs such as credential or azure_endpoint
  2. OPENAI_API_KEY / explicit OpenAI API-key parameters
  3. Azure environment fallback such as AZURE_OPENAI_ENDPOINT and AZURE_OPENAI_API_KEY

This means mixed shells default to OpenAI when OPENAI_API_KEY is present. To force Azure routing, pass an explicit Azure input such as credential=AzureCliCredential().

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='',
    azure_endpoint='',
    model='',
    api_version='',
)

See the following setup guide 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

async def main():
    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 = await agent.run("Summarize the Three Laws of Robotics")
    print(result)

asyncio.run(main())
# 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 import Message
from agent_framework.openai import OpenAIChatClient

async def main():
    client = OpenAIChatClient()

    messages = [
        Message("system", ["You are a helpful assistant."]),
        Message("user", ["Write a haiku about Agent Framework."])
    ]

    response = await client.get_response(messages)
    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 pydantic import Field
from agent_framework import Agent
from agent_framework.openai import OpenAIChatClient


def get_weather(
    location: Annotated[str, Field(description="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.
    """

if __name__ == "__main__":
    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())

For more advanced orchestration patterns including Sequential, Concurrent, Group Chat, Handoff, and Magentic orchestrations, see the orchestration samples.

More Examples & Samples

Agent Framework Documentation