Fixes microsoft/agent-framework#3295. When the OpenAI Responses chat client sends a request that carries previous_response_id / conversation_id / conversation, the server already has the prior turn's response items and rejects duplicates with "Duplicate item found with id fc_xxx". The chat client was re-sending them inline whenever the input messages still carried the items in additional_properties (workflow replay, history providers, etc.), which broke any tool-using agent with persistent history. Decisions: - Single chokepoint: _prepare_message_for_openai. When the resulting request uses service-side storage, drop function_call, reasoning, approval-request/response, and local-shell-call items from the wire input. Keep function_result with its call_id; the server pairs it to the prior function_call via that key. - function_result is preserved unconditionally except for the local-shell variant, which carries its own server-issued item id. - No public API change. Wire format change is subtractive and only on requests that would otherwise 400. - Re-pointed the strict-xfail in test_full_conversation.py from #4047 to #3295. Kept xfail because the test asserts executor-level session-id clearing, which is the defense-in-depth half tracked by 3295-03; this slice closes the wire-level half. Files: - python/packages/openai/agent_framework_openai/_chat_client.py: strip rule applied alongside the existing reasoning-item branch. - python/packages/openai/tests/openai/test_openai_chat_client.py: four new tests pin the contract (function_call, approval, local-shell-call stripped under storage; everything kept without storage). Updated pre-existing tests that exercised the storage-on path to either pass request_uses_service_side_storage=False explicitly or assert the new strip behavior. - python/packages/foundry/tests/foundry/test_foundry_chat_client.py: same explicit storage-off opt-in for the inherited test. - python/packages/core/tests/workflow/test_full_conversation.py: re-pointed xfail reason to #3295 and the executor-level follow-up. Notes for next iteration: - 3295-01 (HITL wire-format validation against live OpenAI/Foundry) was not run; it requires the user's API credentials. The PRD design is locked but the empirical confirmation is still pending. If script 3 fails on either provider, this slice may need to be revisited. - 3295-03 (clear service_session_id in AgentExecutor on full-history replay) remains open. After it lands the xfail in test_full_conversation.py can be removed. - pytest was not run in this iteration because uv-based pytest commands required interactive approval. Validation rests on careful reading; next iteration should run the openai + core test suites.
agent-framework-openai
OpenAI integration for Microsoft Agent Framework.
This package provides:
OpenAIChatClientfor the OpenAI Responses APIOpenAIChatCompletionClientfor the Chat Completions APIOpenAIEmbeddingClientfor 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.
OpenAIChatClientuses the Responses API and is the preferred general-purpose chat client.OpenAIChatCompletionClientuses 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_MODELOpenAIChatCompletionClient:OPENAI_CHAT_COMPLETION_MODEL->OPENAI_MODELOpenAIEmbeddingClient: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_MODELOpenAIChatCompletionClient:AZURE_OPENAI_CHAT_COMPLETION_MODEL->AZURE_OPENAI_MODELOpenAIEmbeddingClient: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")