Files
microsoft--agent-framework/python/packages/openai
Giles Odigwe b2a2fcbd87 Python: Add response/request customization hooks to OpenAIChatCompletionClient (#7028)
* Python: Fix reasoning content parsing in OpenAIChatCompletionClient

Fix two issues with reasoning content handling in the Chat Completions
client:

1. (#6979) reasoning_details plaintext buried as encrypted data:
   The client dumped the entire reasoning_details array into
   Content.protected_data without setting Content.text, causing AG-UI
   to emit ReasoningEncryptedValueEvent instead of visible
   ReasoningMessageContentEvent for plaintext reasoning providers
   (e.g. OpenRouter). Now extracts readable text from reasoning_details
   entries into Content.text while preserving protected_data for
   round-trip fidelity.

2. (#6978) Mistral list content causes crash:
   Mistral reasoning models return content as a list of typed chunks
   ([{"type": "thinking", ...}, {"type": "text", ...}]) instead of a
   plain string. _parse_text_from_openai assumed content was always a
   string, causing a Pydantic ValidationError downstream. Now detects
   list content and parses thinking chunks as Content.from_text_reasoning
   and text chunks as Content.from_text.

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

* Fix pyright strict-mode type errors and handle content-as-string shape

- Use cast() for proper type narrowing in _extract_reasoning_text and
  _parse_chunked_content to satisfy pyright strict mode
- Handle {"content": "..."} string shape in _extract_reasoning_text
  (addresses review comment about missing format coverage)

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

* Fix mypy errors: cast list content to Any in tests

model_construct bypasses Pydantic runtime validation but mypy still
checks declared types. Use cast(Any, ...) for the list content args.

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

* Address review comments: summary field, reasoning field, and round-trip

- Add 'summary' field extraction in _extract_reasoning_text for
  reasoning.summary entries from OpenRouter
- Handle message.reasoning and message.reasoning_content top-level
  fields (plaintext reasoning without reasoning_details) in both
  streaming and non-streaming paths
- reasoning_details takes priority when both fields are present
- Preserve original Mistral chunk list in additional_properties
  ('_source_content_list') so _prepare_message_for_openai can
  reconstruct the structured list content for multi-turn reasoning
- Add 5 new tests covering all new behaviors

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

* Fix ruff used-dummy-variable: rename _skip_structured_siblings

Remove leading underscore from _skip_structured_siblings variable since
it is accessed (not a dummy variable). Ruff's used-dummy-variable rule
flags variables with leading underscores that are read.

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

* Fix missing newline at end of test file

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

* Address review: type-agnostic chunk round-trip and reasoning field echo-back

- Honor the _source_content_list marker regardless of the first emitted
  content's type by handling it before the type match, so a chunk list
  beginning with a text chunk still round-trips as one structured message
  (addresses github-actions review comment on results[0]).
- Tag every chunked-content item with a shared _structured_content_group
  id and skip only exact group siblings during serialization, instead of
  suppressing all later text/reasoning content.
- Record provenance of top-level reasoning/reasoning_content fields in
  _reasoning_source_field and echo the value back under the same key on
  the next request, which providers such as vLLM require (addresses
  Kimahriman review comment). Replaces the prior behavior that replayed
  surfaced reasoning as visible answer text.
- Factor the duplicated reasoning parsing into _parse_reasoning_content.
- Add tests for provenance capture, reasoning/reasoning_content round-trip,
  reasoning-only messages, text-first chunk round-trip, and unrelated
  sibling preservation.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 2f3c0308-51bf-4b66-8b53-87a8546743f5

* Replace provider-specific reasoning logic with configurable parse/prepare hooks

Following review feedback (#7028), keep OpenAIChatCompletionClient free of
provider-specific quirks for 'almost OpenAI-compatible' endpoints. Instead of
branching in core for OpenRouter/vLLM/Mistral, expose two optional callables so
callers adapt the client themselves:

- response_parser (OpenAIChatResponseContentsParser): post-processes the Content
  list parsed from each response choice/streaming delta, to surface non-standard
  fields (e.g. reasoning/reasoning_content/reasoning_details) for display.
- message_preparer (OpenAIChatMessagePreparer): post-processes the outgoing request
  message dicts built from each framework Message, to echo provider-specific fields
  back on later turns (e.g. vLLM reasoning) for multi-turn continuity.

Both default to None (no-op; byte-identical stock OpenAI behavior). This reverts the
provider-specific reasoning/chunked-content parsing and round-trip markers previously
added to core; Mistral chunked content is now handled by agent-framework-mistral.

- Add the two callables to RawOpenAIChatCompletionClient / OpenAIChatCompletionClient
  constructors and invoke them at the parse and prepare seams.
- Export the type aliases from the package and the core lazy openai namespace (+ .pyi).
- Replace the removed-behavior tests with tests for the two hooks.
- Document the hooks in packages/openai/AGENTS.md.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 2f3c0308-51bf-4b66-8b53-87a8546743f5

* Skip non-string content in default text parsing

Structured list content (e.g. Mistral reasoning models returning content as a
list of chunks) was wrapped verbatim into a text Content, producing a malformed
Content whose text is a list that crashes downstream (issue #6978). Default text
parsing now skips non-string content so a configured response_parser receives a
clean slate to expand it. Applies to both streaming and non-streaming paths.

Add tests for the skip and for a response_parser expanding chunked content.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 2f3c0308-51bf-4b66-8b53-87a8546743f5

* Address review: hook signature, per-role preparer, robust round-trip

- response_parser now receives the already-selected ChatCompletionMessage /
  ChoiceDelta instead of Choice | ChunkChoice, so callers no longer duplicate the
  streaming dispatch (removes the Any/hasattr pattern from tests). The client owns
  the dispatch; parsers read provider fields directly.
- message_preparer now runs once per Message for every role: the build logic moved
  to _build_openai_messages and the hook is applied at a single exit point in
  _prepare_message_for_openai, so system/developer messages no longer bypass it.
- Round-trip example/test now correlates surfaced reasoning via an
  additional_properties marker on message.contents with bounded, order-aware,
  one-to-one dict removal, instead of fragile request-string matching. Adds a test
  proving an answer whose text equals the reasoning text is no longer dropped.
- Update packages/openai/AGENTS.md for the new parser signature and guidance.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 2f3c0308-51bf-4b66-8b53-87a8546743f5

---------

Co-authored-by: Copilot <copilot@github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 2f3c0308-51bf-4b66-8b53-87a8546743f5
2026-08-07 02:51:06 +00:00
..

agent-framework-openai

OpenAI integration for Microsoft Agent Framework.

This package provides:

  • OpenAIChatClient for the OpenAI Responses API
  • OpenAIChatCompletionClient for the Chat Completions API
  • OpenAIEmbeddingClient for embeddings

Installation

pip install agent-framework-openai

Which chat client should I use?

Use OpenAIChatClient for new work unless you specifically need the Chat Completions API.

  • OpenAIChatClient uses the Responses API and is the preferred general-purpose chat client.
  • OpenAIChatCompletionClient uses the Chat Completions API and is mainly for compatibility with existing Chat Completions-based integrations.

The previous deprecated Responses alias has been removed. Use OpenAIChatClient directly.

Environment variables

OpenAI

These variables are used when the client is configured for OpenAI:

Variable Purpose
OPENAI_API_KEY OpenAI API key
OPENAI_ORG_ID OpenAI organization ID
OPENAI_BASE_URL Custom OpenAI-compatible base URL
OPENAI_MODEL Generic fallback model
OPENAI_CHAT_MODEL Preferred model for OpenAIChatClient
OPENAI_CHAT_COMPLETION_MODEL Preferred model for OpenAIChatCompletionClient
OPENAI_EMBEDDING_MODEL Preferred model for OpenAIEmbeddingClient

Model lookup order:

  • OpenAIChatClient: OPENAI_CHAT_MODEL -> OPENAI_MODEL
  • OpenAIChatCompletionClient: OPENAI_CHAT_COMPLETION_MODEL -> OPENAI_MODEL
  • OpenAIEmbeddingClient: OPENAI_EMBEDDING_MODEL -> OPENAI_MODEL

These model variables are only consulted when you do not pass model= directly. In other words, OpenAIChatClient(model="...") ignores OPENAI_CHAT_MODEL, and OpenAIChatCompletionClient(model="...") ignores OPENAI_CHAT_COMPLETION_MODEL.

Azure OpenAI

These variables are used when the client is configured for Azure OpenAI:

Variable Purpose
AZURE_OPENAI_ENDPOINT Azure OpenAI resource endpoint
AZURE_OPENAI_BASE_URL Full Azure OpenAI base URL (.../openai/v1)
AZURE_OPENAI_API_KEY Azure OpenAI API key
AZURE_OPENAI_API_VERSION Azure OpenAI API version
AZURE_OPENAI_MODEL Generic fallback deployment
AZURE_OPENAI_CHAT_MODEL Preferred deployment for OpenAIChatClient
AZURE_OPENAI_CHAT_COMPLETION_MODEL Preferred deployment for OpenAIChatCompletionClient
AZURE_OPENAI_EMBEDDING_MODEL Preferred deployment for OpenAIEmbeddingClient

Deployment lookup order:

  • OpenAIChatClient: AZURE_OPENAI_CHAT_MODEL -> AZURE_OPENAI_MODEL
  • OpenAIChatCompletionClient: AZURE_OPENAI_CHAT_COMPLETION_MODEL -> AZURE_OPENAI_MODEL
  • OpenAIEmbeddingClient: AZURE_OPENAI_EMBEDDING_MODEL -> AZURE_OPENAI_MODEL

For Azure routing, the same rule applies: the client-specific deployment variable is checked first, then the generic AZURE_OPENAI_MODEL fallback. Passing model= overrides both environment variables.

When both OpenAI and Azure environment variables are present, the generic clients prefer OpenAI when OPENAI_API_KEY is configured. To use Azure explicitly, pass azure_endpoint or credential.

OpenAI example

from agent_framework.openai import OpenAIChatClient

client = OpenAIChatClient(model="gpt-4.1")

Azure OpenAI example

from azure.identity.aio import AzureCliCredential

from agent_framework.openai import OpenAIChatClient

client = OpenAIChatClient(
    model="my-responses-deployment",
    azure_endpoint="https://my-resource.openai.azure.com",
    credential=AzureCliCredential(),
)

ChatClient vs ChatCompletionClient

Use OpenAIChatClient when you want the Responses API as your default chat surface.

Use OpenAIChatCompletionClient when you specifically need the Chat Completions API:

from agent_framework.openai import OpenAIChatCompletionClient

client = OpenAIChatCompletionClient(model="gpt-4o-mini")