Files
MohammadHaroonAbuomar 7302d0bf23 Python: agent-hooks interception contract as a first-class experimental core feature (#7515)
* feat(python): add agent-hooks middleware as experimental core feature

Implement the AGENT-HOOKS-0.1 interception contract as a first-class
experimental feature in agent_framework core.

- Single public factory agent_hooks_middleware() returning a private
  agent/chat/function middleware trio (one object per middleware
  category); partial or stacked installs fail closed with loud errors.
- All eight interception points: input/output at the agent seam,
  pre/post_model_call at the chat seam, pre/post_tool_call at the
  function seam, agent_startup/agent_shutdown bracketing each run.
- Fail-closed enforcement throughout: transforms write back into the
  native contexts (messages, arguments, results) or raise; content is
  preserved as Content objects; MiddlewareTermination short-circuits
  are guarded at every seam; enforcement-layer failures halt the run;
  interceptor crashes surface as host_error denies.
- Streaming is fully buffered per spec buffered_output semantics: no
  update egresses before the post_model_call/output verdicts; a deny
  at pull time releases zero updates; run state stays active across
  lazy pulls with cleanup on every exit path.
- Session scoping: per-run by default (startup/shutdown bracket each
  run) or host-owned via emitter/builder parameters for one session
  spanning multiple runs.
- agent-hooks-sdk is an opt-in agent-hooks extra (not in all),
  lazy-imported per the _mcp.py pattern; core imports cleanly without
  it and the factory raises a clear ModuleNotFoundError.
- ExperimentalFeature.AGENT_HOOKS + @experimental decorator, lazy root
  export, typing surface, PACKAGE_STATUS.md entry.
- 55 tests built on real Agent/mock-client flows covering deny-before-
  execution, transform write-back, rich-content preservation, complete
  streaming ordering, error cleanup, concurrency isolation, nested
  agents, and importability without the optional SDK.

Signed-off-by: MohammadHaroonAbuomar <40180927+MohammadHaroonAbuomar@users.noreply.github.com>

* style(python): unquote ResponseStream annotation per pyupgrade

The pre-commit pyupgrade hook rewrites the quoted forward reference;
ResponseStream is imported at runtime in this module, so the quotes
were unnecessary.

Signed-off-by: MohammadHaroonAbuomar <40180927+MohammadHaroonAbuomar@users.noreply.github.com>

* refactor(python): address agent-hooks review feedback

Reworks the agent-hooks feature per PR review:

- Verdicts now precede durability: a run-scoped persistence gate
  (_sessions.py) defers per-service-call history persistence and
  after-run provider work until the covering post_model_call/output
  verdict permits; denied content never persists, transforms persist
  post-write-back. Unhooked runs are unchanged (verified against an
  instrumented baseline).
- ResponseStream.buffered_and_gated: a buffered-gate combinator that
  applies the run's pending stream hooks before the gate, then seals
  the stream, so no middleware can rewrite egress after the output
  verdict. Replaces the hand-rolled replay iterator.
- MiddlewareBundle (public, _middleware.py): the factory returns an
  indivisible bundle categorize_middleware splits, making partial
  installs impossible by construction; members are validated at
  construction. Bare (non-sequence) middleware at agent construction
  is now normalized instead of silently dropped, and unrecognized
  middleware logs a warning instead of vanishing.
- Factory split and rename: create_agent_hooks_middleware (per-run
  sessions) and create_agent_hooks_middleware_from_emitter
  (host-owned); the sentinel parameter-diffing is gone.
- Wire conversions live in per-point codec classes owning to_wire and
  write_back. Fixes in that code: tool-call name transforms apply or
  raise; non-object args transforms raise; argument write-back merges
  only changed keys (original values, including bytes, preserved by
  identity); message-list write-back matches by identity, not index.
- function_approval_request objects on the normal return path pass
  through un-emitted, preserving the human approval pause.
- Hosted (service-executed) tool calls surface in the post_model_call
  content projection; the tool-seam limitation is documented.
- Import probe covers the full SDK surface and re-raises as
  missing-extra only for the agent_hooks module; module logger added;
  _json_safe replaced by make_json_safe (which gained bytes support);
  tools_registered uses normalize_tools; dependency-pyright analyzes
  the module again via the test dependency-group.
- Tests: 75 in the feature suite (persistence gating, stream-hook
  sealing, approval passthrough, codec units, bundle validation,
  bare-bundle installs), full core suite green.

Signed-off-by: MohammadHaroonAbuomar <40180927+MohammadHaroonAbuomar@users.noreply.github.com>

* refactor(python): second review round for agent-hooks

Addresses the second review round on the agent-hooks feature:

- Nested-run persistence ownership: RawAgent.run stamps a run identity
  over the run's dynamic extent (including streaming pulls and result
  hooks); the persistence gate binds to its owning run via an
  offer/adopt handshake keyed to the agent instance and accepts only
  its owner's persists — nested runs persist inline regardless of how
  they were started (tool calls, middleware, custom run loops). The
  tool-seam suspension remains for custom-loop sub-agents invoked as
  tools; the one residual case (custom loop nested in a custom loop
  off the tool path) is fail-closed and documented. Fixes a latent
  pre-existing re-deferral: flush() now drains with the gate context
  suspended, so a nested hooked run's permitted after-run persistence
  no longer re-defers into an enclosing gate.
- as_tool stream_callback consumes the released (verdicted) stream;
  observers cannot see denied or pre-transform content. Both
  directions are regression-tested.
- categorize_middleware gained supported_categories: a bundle member
  landing in a category a call site cannot install raises; bare
  middleware warns like _add_middleware. Wired at the chat-client
  sites and the provider seam.
- ResponseStream.buffered_and_gated owns the re-derivation rule via a
  rederive callable (gates cannot choose released updates) and is
  marked experimental.
- Wire codecs compare with bool-aware equality (Python == equates
  1 == True, which made bool/number transforms look untouched and get
  dropped) and _ToolResultCodec.write_back owns the untouched-wire
  rule via the before value.
- middleware parameters accept a bare middleware or bundle everywhere
  the runtime does (constructors, run overloads, as_agent, telemetry
  and harness layers, foundry); the bare-source rule has a single
  owner in categorize_middleware; bare middleware assigned to the
  attribute now executes (documented behavior change).
- MiddlewareBundle is experimental and validates members; approval
  passthrough, typing-check fixes (ty ignores mypy-coded ignore
  comments), logging, and documentation updates per review.

Test count: 85 feature tests plus 12 new this round across sessions,
middleware, agents; full core suite green; typing checked under
mypy, pyrefly, ty, zuban, and pyright.

Signed-off-by: MohammadHaroonAbuomar <40180927+MohammadHaroonAbuomar@users.noreply.github.com>

* docs(python): drop previous-behavior notes from middleware docstrings

Per review: docstrings describe current behavior only. The
bare-middleware behavior change stays recorded in the PR description
and commit history.

Signed-off-by: MohammadHaroonAbuomar <40180927+MohammadHaroonAbuomar@users.noreply.github.com>

* fix(python): gate ownership survives retrying middleware

A retry or fallback middleware issuing a second call_next() gave the
new attempt a fresh run identity that the persistence gate's
first-bind-wins ownership rejected, so the retried attempt's history
persisted inline before the output verdict — a denied response became
durable again. The gate now accumulates every identity adopted
through its own offer ticket: all attempts' persistence stays behind
the one final verdict (deny drops all of it, allow flushes all of
it). Accumulation over rebind-replace is deliberate: rebinding would
flip an earlier attempt's still-running background work from deferred
to inline, which is the fail-open direction. A foreign agent still
cannot bind: tickets are minted only by the covered pipeline's final
handler and adoption is instance-keyed.

Also consolidates the bare-middleware-source rule into a single
_as_middleware_list owner used by every interpretation site (the
harness merge, BaseAgent.__init__, categorize_middleware, both
client-kwargs merges, get_response, SessionContext.extend_middleware),
including the str/bytes exclusion the stray copies missed. The
constructor now stores a copy of the caller's sequence; assign to the
middleware attribute for post-construction changes.

Retry regression tests cover denied and allowed retried runs in both
stream modes and fail with first-bind-wins restored.

Signed-off-by: MohammadHaroonAbuomar <40180927+MohammadHaroonAbuomar@users.noreply.github.com>

* fix(python): streaming seam runs pipeline descent inside the gate

The streaming agent seam ran call_next() outside the persistence
gate (only _consume entered it later), so a retry middleware that
drained a successful attempt with get_final_response() and discarded
it persisted that attempt's exchange before any verdict existed; a
later deny dropped only the retry attempt's deferred work. The
descent is now wrapped in the gate exactly like the non-streaming
seam: attempt identities adopted during descent are accepted owners,
so in-pipeline draining defers, deny drops every attempt, and a
middleware that raises after draining strands the pending persists
unexecuted. The bind_owner docstring now states the actual soundness
invariant covering both bind sites: every bind comes from a run
inside the covered pipeline.

New tests cover drained-and-discarded attempts (deny and allow, both
stream modes) and a sub-agent tool inside a drained attempt; the
streaming deny variant fails with the gate wrap reverted.

Signed-off-by: MohammadHaroonAbuomar <40180927+MohammadHaroonAbuomar@users.noreply.github.com>

* fix(python): flush deferred persistence on streaming no-result termination

With the pipeline descent now running inside the persistence gate, a
middleware that drains a successful attempt and then terminates
without a result left that attempt's deferred persistence stranded:
the streaming no-result termination path raised before any flush, so
history of exchanges that really happened and passed their own
verdicts quietly vanished (streaming only; non-streaming already
flushes before its re-raise). The path now flushes before re-raising
the termination, with a state.halted guard first so an enforcement
failure during the drained attempt still strands pending fail-closed
and surfaces the halt, mirroring the non-streaming ordering exactly.

The regression test covers both seams; the streaming variant fails
without the fix.

Signed-off-by: MohammadHaroonAbuomar <40180927+MohammadHaroonAbuomar@users.noreply.github.com>

---------

Signed-off-by: MohammadHaroonAbuomar <40180927+MohammadHaroonAbuomar@users.noreply.github.com>
2026-08-07 00:25:09 +00:00
..

Agent Framework Foundry

This package contains the Microsoft Foundry integrations for Microsoft Agent Framework, including Foundry chat clients, preconfigured Foundry agents, Foundry embedding clients, and Foundry memory providers.

Toolboxes

A toolbox is a named, versioned bundle of hosted tool configurations — code interpreter, file search, image generation, MCP, web search, and so on — stored inside a Microsoft Foundry project. Toolboxes let you manage tool configuration once and reuse it across agents.

Authoring a toolbox

Toolboxes can be authored two ways:

  • Foundry portal — create and version toolboxes through the UI without touching code.
  • Programmatically — use the azure-ai-projects SDK to create, update, and version toolboxes from Python.

Toolbox authoring APIs (ToolboxVersionObject, ToolboxObject, project_client.beta.toolboxes.*) require azure-ai-projects>=2.1.0. Earlier versions can only consume toolboxes that already exist.

Using toolboxes with FoundryAgent

For hosted FoundryAgent, the toolbox must already be attached to the agent in the Microsoft Foundry project. Once attached, the agent invokes its toolbox tools transparently — no client-side wiring required — and you interact with the agent the same way you would with any other tool-equipped Foundry agent.

Using toolboxes with FoundryChatClient

Each toolbox is reachable as an MCP server. Connect to the toolbox's MCP endpoint with MCPStreamableHTTPTool — the agent then discovers and calls its tools over MCP at runtime:

from agent_framework import Agent, MCPStreamableHTTPTool
from agent_framework.foundry import FoundryChatClient

async with Agent(
    client=FoundryChatClient(...),
    instructions="You are a helpful assistant. Use the toolbox tools when useful.",
    tools=MCPStreamableHTTPTool(
        name="my_toolbox",
        description="Tools served by my Foundry toolbox",
        url="https://<your-toolbox-mcp-endpoint>",
    ),
) as agent:
    result = await agent.run("What tools are available?")
    print(result.text)

Hosted tool factories

FoundryChatClient exposes static factory methods that return Foundry SDK tool configurations ready to pass to an Agent's tools=[...] argument. These factories don't require a FoundryChatClient instance — you can call them statically and reuse the same tool configuration across agents.

from agent_framework import Agent
from agent_framework.foundry import FoundryChatClient

agent = Agent(
    client=FoundryChatClient(...),
    instructions="...",
    tools=[
        FoundryChatClient.get_web_search_tool(),
        FoundryChatClient.get_code_interpreter_tool(),
    ],
)

Generally available factories: get_code_interpreter_tool, get_file_search_tool, get_web_search_tool, get_image_generation_tool, get_mcp_tool.

Choosing a web grounding tool. get_web_search_tool is the recommended default — it requires no separate Bing resource and works with Azure OpenAI models out of the box. Reach for get_bing_grounding_tool (experimental, see below) when you need finer Bing parameters (count, freshness, market, set_lang), are grounding non-OpenAI Foundry models, or are migrating from Grounding with Bing Search on the classic platform — it requires a Grounding with Bing Search Azure resource that you manage. get_bing_custom_search_tool (also experimental) is for grounding restricted to a curated list of domains via a Bing Custom Search instance. See the web grounding overview for the full comparison.

Experimental — ExperimentalFeature.FOUNDRY_TOOLS. The following factories wrap GA Foundry tool SDK classes but are new wrappers in agent-framework-foundry and may change before the wrappers themselves reach GA. Calls emit an ExperimentalWarning the first time the FOUNDRY_TOOLS feature is exercised in a process (then deduplicated).

Factory Foundry SDK tool
get_azure_ai_search_tool(index_connection_id, index_name, ...) AzureAISearchTool
get_bing_grounding_tool(connection_id, ...) BingGroundingTool

Experimental — ExperimentalFeature.FOUNDRY_PREVIEW_TOOLS. The following factories wrap preview Foundry tool SDK types — the underlying Foundry capability itself is in preview and may change or be removed before reaching GA. Calls emit a separate ExperimentalWarning the first time the FOUNDRY_PREVIEW_TOOLS feature is exercised in a process (then deduplicated). Use FOUNDRY_TOOLS for "wrapper is new" and FOUNDRY_PREVIEW_TOOLS for "underlying Foundry feature is preview".

Factory Foundry SDK tool
get_sharepoint_tool(connection_id) SharepointPreviewTool
get_fabric_tool(connection_id) MicrosoftFabricPreviewTool
get_memory_search_tool(memory_store_name, scope, ...) MemorySearchPreviewTool
get_computer_use_tool(environment, display_width, display_height) ComputerUsePreviewTool
get_browser_automation_tool(connection_id) BrowserAutomationPreviewTool
get_bing_custom_search_tool(connection_id, instance_name, ...) BingCustomSearchPreviewTool
get_a2a_tool(base_url=..., project_connection_id=..., ...) A2APreviewTool

Creating Foundry conversation sessions

FoundryAgent.create_conversation() creates a server-side Foundry project conversation and returns an AgentSession that can be passed to agent.run(...) without reaching into the raw OpenAI client.

from agent_framework.foundry import FoundryAgent

agent = FoundryAgent(
    project_endpoint=project_endpoint,
    agent_name="travel-agent",
    credential=credential,
)

session = await agent.create_conversation()
response = await agent.run("Help me plan a trip to Seattle.", session=session)

This is separate from hosted-agent isolation_key sessions: the created conversation ID is stored on AgentSession.service_session_id, while the local session_id remains available for application/session storage.

Publishing an agent as a Foundry prompt agent

Experimental — ExperimentalFeature.TO_PROMPT_AGENT. to_prompt_agent is a preview API and may change before reaching GA. The warning fires the first time the TO_PROMPT_AGENT feature is exercised in a process and is then deduplicated.

to_prompt_agent(agent) converts an Agent whose chat client is a FoundryChatClient into a Foundry PromptAgentDefinition that can be published with AIProjectClient.agents.create_version(...). The model is read from default_options["model"] first and falls back to the bound FoundryChatClient.model (matching Agent.__init__'s resolution order), so the same agent definition you run locally can be published as a hosted prompt agent without restating the model deployment name.

Every generation parameter that has an Agent Framework equivalent is sourced from agent.default_options and translated into the matching Foundry shape by _prepare_prompt_agent_options (a module-private helper in agent_framework_foundry._to_prompt_agent that reuses the chat client's own request-path helpers):

default_options key PromptAgentDefinition field
temperature temperature
top_p top_p
tool_choice (dropped when no tools) tool_choice (str / ToolChoiceFunction / ToolChoiceAllowed)
reasoning (dict or Reasoning) reasoning
response_format (dict or BaseModel) text.format
verbosity text.verbosity
text merged into text

This keeps the Agent as the single source of truth for everything it can already express. Only Foundry-specific fields with no Agent Framework equivalent are accepted as keyword arguments on to_prompt_agent:

  • structured_inputsdict[str, StructuredInputDefinition]
  • rai_configRaiConfig
import asyncio
import os

from agent_framework import Agent
from agent_framework.foundry import FoundryChatClient, to_prompt_agent
from azure.ai.projects.aio import AIProjectClient
from azure.identity.aio import AzureCliCredential


async def main() -> None:
    credential = AzureCliCredential()
    project_endpoint = os.environ["FOUNDRY_PROJECT_ENDPOINT"]

    agent = Agent(
        client=FoundryChatClient(
            project_endpoint=project_endpoint,
            model="gpt-4o",
            credential=credential,
        ),
        name="travel-agent",
        description="Helps Contoso employees book travel.",
        instructions="You are a helpful travel assistant.",
        tools=[
            FoundryChatClient.get_web_search_tool(),
            FoundryChatClient.get_code_interpreter_tool(),
        ],
        # Generation parameters set on the Agent flow through automatically.
        default_options={
            "temperature": 0.3,
            "top_p": 0.95,
            "reasoning": {"effort": "medium"},
        },
    )

    definition = to_prompt_agent(agent)

    project_client = AIProjectClient(endpoint=project_endpoint, credential=credential)
    created = await project_client.agents.create_version(
        agent_name=agent.name,
        definition=definition,
        description=agent.description,
    )
    print(f"Published {created.name} v{created.version}")


asyncio.run(main())

Behaviour:

  • agent.client must be a FoundryChatClient (or subclass) — otherwise the converter raises TypeError.

  • The bound client must have a model set — otherwise the converter raises ValueError.

  • Foundry SDK tool instances returned by FoundryChatClient.get_*_tool() are passed through unchanged.

  • AF FunctionTool instances (and @tool-decorated callables) are emitted as Foundry FunctionTool declarations — the prompt agent receives the schema only, not the Python implementation. To execute the function when invoking the deployed prompt agent, connect with FoundryAgent and pass the same callable via tools=:

    from agent_framework.foundry import FoundryAgent
    
    deployed = FoundryAgent(
        project_endpoint=project_endpoint,
        agent_name="travel-agent",
        credential=credential,
        tools=[book_hotel],  # same @tool-decorated callable used at publish time
    )
    result = await deployed.run("Book me a hotel in Seattle for 3 nights.")
    

    FoundryAgent runs the function locally when the prompt agent calls it, so the declaration on the server and the implementation on the client stay in sync via the shared @tool definition.

  • Local Agent Framework MCP tools cannot be published as prompt-agent tools — the converter raises ValueError and points at FoundryChatClient.get_mcp_tool(...) for hosted MCP servers.

See the runnable example under samples/02-agents/providers/foundry/:

  • foundry_prompt_agents.py — publish with to_prompt_agent, then connect back with FoundryAgent and execute the same local @tool callable that the deployed prompt agent invokes by name.