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Fix OpenAI Responses API tool calls with reasoning #2869

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Merged
merged 4 commits into from
Sep 11, 2025
Merged

Fix OpenAI Responses API tool calls with reasoning #2869

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e0f74c6
Fix OpenAI Responses API tool calls with reasoning
DouweM Sep 11, 2025
17eb469
fix test snapshots
DouweM Sep 11, 2025
0c155f1
fix test
DouweM Sep 11, 2025
204b379
coverage
DouweM Sep 11, 2025
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58 changes: 41 additions & 17 deletions pydantic_ai_slim/pydantic_ai/models/openai.py
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Original file line number Diff line number Diff line change
Expand Up @@ -878,7 +878,9 @@ def _process_response(self, response: responses.Response) -> ModelResponse:
if isinstance(content, responses.ResponseOutputText): # pragma: no branch
items.append(TextPart(content.text))
elif isinstance(item, responses.ResponseFunctionToolCall):
items.append(ToolCallPart(item.name, item.arguments, tool_call_id=item.call_id))
items.append(
ToolCallPart(item.name, item.arguments, tool_call_id=_combine_tool_call_ids(item.call_id, item.id))
)

finish_reason: FinishReason | None = None
provider_details: dict[str, Any] | None = None
Expand Down Expand Up @@ -1084,27 +1086,29 @@ async def _map_messages( # noqa: C901
elif isinstance(part, UserPromptPart):
openai_messages.append(await self._map_user_prompt(part))
elif isinstance(part, ToolReturnPart):
openai_messages.append(
FunctionCallOutput(
type='function_call_output',
call_id=_guard_tool_call_id(t=part),
output=part.model_response_str(),
)
call_id = _guard_tool_call_id(t=part)
call_id, _ = _split_combined_tool_call_id(call_id)
item = FunctionCallOutput(
type='function_call_output',
call_id=call_id,
output=part.model_response_str(),
)
openai_messages.append(item)
elif isinstance(part, RetryPromptPart):
# TODO(Marcelo): How do we test this conditional branch?
if part.tool_name is None: # pragma: no cover
openai_messages.append(
Message(role='user', content=[{'type': 'input_text', 'text': part.model_response()}])
)
else:
openai_messages.append(
FunctionCallOutput(
type='function_call_output',
call_id=_guard_tool_call_id(t=part),
output=part.model_response(),
)
call_id = _guard_tool_call_id(t=part)
call_id, _ = _split_combined_tool_call_id(call_id)
item = FunctionCallOutput(
type='function_call_output',
call_id=call_id,
output=part.model_response(),
)
openai_messages.append(item)
else:
assert_never(part)
elif isinstance(message, ModelResponse):
Expand Down Expand Up @@ -1141,12 +1145,18 @@ async def _map_messages( # noqa: C901

@staticmethod
def _map_tool_call(t: ToolCallPart) -> responses.ResponseFunctionToolCallParam:
return responses.ResponseFunctionToolCallParam(
arguments=t.args_as_json_str(),
call_id=_guard_tool_call_id(t=t),
call_id = _guard_tool_call_id(t=t)
call_id, id = _split_combined_tool_call_id(call_id)

param = responses.ResponseFunctionToolCallParam(
name=t.tool_name,
arguments=t.args_as_json_str(),
call_id=call_id,
type='function_call',
)
if id: # pragma: no branch
param['id'] = id
return param

def _map_json_schema(self, o: OutputObjectDefinition) -> responses.ResponseFormatTextJSONSchemaConfigParam:
response_format_param: responses.ResponseFormatTextJSONSchemaConfigParam = {
Expand Down Expand Up @@ -1365,7 +1375,7 @@ async def _get_event_iterator(self) -> AsyncIterator[ModelResponseStreamEvent]:
vendor_part_id=chunk.item.id,
tool_name=chunk.item.name,
args=chunk.item.arguments,
tool_call_id=chunk.item.call_id,
tool_call_id=_combine_tool_call_ids(chunk.item.call_id, chunk.item.id),
)
elif isinstance(chunk.item, responses.ResponseReasoningItem):
pass
Expand Down Expand Up @@ -1506,3 +1516,17 @@ def _map_usage(response: chat.ChatCompletion | ChatCompletionChunk | responses.R
u.input_audio_tokens = response_usage.prompt_tokens_details.audio_tokens or 0
u.cache_read_tokens = response_usage.prompt_tokens_details.cached_tokens or 0
return u


def _combine_tool_call_ids(call_id: str, id: str | None) -> str:
# When reasoning, the Responses API requires the `ResponseFunctionToolCall` to be returned with both the `call_id` and `id` fields.
# Our `ToolCallPart` has only the `call_id` field, so we combine the two fields into a single string.
return f'{call_id}|{id}' if id else call_id


def _split_combined_tool_call_id(combined_id: str) -> tuple[str, str | None]:
if '|' in combined_id:
call_id, id = combined_id.split('|', 1)
return call_id, id
else:
return combined_id, None # pragma: no cover
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