Fix reasoning

Author: mwildehahn

pydantic_ai_slim/pydantic_ai/messages.py

@@ -351,6 +351,8 @@ class ToolReturnPart:
     tool_call_id: str
     """The tool call identifier, this is used by some models including OpenAI."""
 
+    id: str | None = None
+
     timestamp: datetime = field(default_factory=_now_utc)
     """The timestamp, when the tool returned."""
 
@@ -510,6 +512,8 @@ class ToolCallPart:
     This is stored either as a JSON string or a Python dictionary depending on how data was received.
     """
 
+    id: str | None = None
+
     tool_call_id: str = field(default_factory=_generate_tool_call_id)
     """The tool call identifier, this is used by some models including OpenAI.
 
@@ -799,8 +803,9 @@ def _apply_to_part(self, part: ToolCallPart) -> ToolCallPart:
             updated_dict = {**(part.args or {}), **self.args_delta}
             part = replace(part, args=updated_dict)
 
+        # Does this ever change? Not sure why this is needed
         if self.tool_call_id:
-            part = replace(part, tool_call_id=self.tool_call_id)
+            part = replace(part, id=self.tool_call_id)
         return part
 
 

pydantic_ai_slim/pydantic_ai/models/openai.py

@@ -723,24 +723,22 @@ async def _map_messages(
                     else:
                         assert_never(part)
             elif isinstance(message, ModelResponse):
-                thinking_parts: list[ThinkingPart] = []
                 for item in message.parts:
                     if isinstance(item, TextPart):
                         openai_messages.append(responses.EasyInputMessageParam(role='assistant', content=item.content))
                     elif isinstance(item, ToolCallPart):
                         openai_messages.append(self._map_tool_call(item))
                     elif isinstance(item, ThinkingPart):
-                        thinking_parts.append(item)
+                        # Reasoning needs to precede the tool call, it shouldn't get added last
+                        openai_messages.append(
+                            responses.ResponseReasoningItemParam(
+                                id=item.signature or '',
+                                summary=[Summary(text=item.content, type='summary_text')],
+                                type='reasoning',
+                            )
+                        )
                     else:
                         assert_never(item)
-                if thinking_parts:
-                    openai_messages.append(
-                        responses.ResponseReasoningItemParam(
-                            id=thinking_parts[0].signature or '',
-                            summary=[Summary(text=item.content, type='summary_text') for item in thinking_parts],
-                            type='reasoning',
-                        )
-                    )
             else:
                 assert_never(message)
         instructions = self._get_instructions(messages) or NOT_GIVEN
@@ -749,6 +747,7 @@ async def _map_messages(
     @staticmethod
     def _map_tool_call(t: ToolCallPart) -> responses.ResponseFunctionToolCallParam:
         return responses.ResponseFunctionToolCallParam(
+            id=t.id or '',
             arguments=t.args_as_json_str(),
             call_id=_guard_tool_call_id(t=t),
             name=t.tool_name,
@@ -892,6 +891,15 @@ async def _get_event_iterator(self) -> AsyncIterator[ModelResponseStreamEvent]:
             elif isinstance(chunk, responses.ResponseContentPartDoneEvent):
                 pass  # there's nothing we need to do here
 
+            elif isinstance(chunk, responses.ResponseReasoningSummaryPartAddedEvent):
+                pass  # there's nothing we need to do here
+
+            elif isinstance(chunk, responses.ResponseReasoningSummaryPartDoneEvent):
+                pass  # there's nothing we need to do here
+
+            elif isinstance(chunk, responses.ResponseReasoningSummaryTextDoneEvent):
+                pass  # there's nothing we need to do here
+
             elif isinstance(chunk, responses.ResponseCreatedEvent):
                 pass  # there's nothing we need to do here
 
@@ -923,11 +931,15 @@ 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.id,
+                        tool_call_id=chunk.item.call_id,
                     )
                 elif isinstance(chunk.item, responses.ResponseReasoningItem):
                     content = chunk.item.summary[0].text if chunk.item.summary else ''
-                    yield self._parts_manager.handle_thinking_delta(vendor_part_id=chunk.item.id, content=content)
+                    yield self._parts_manager.handle_thinking_delta(
+                        vendor_part_id=chunk.item.id,
+                        content=content,
+                        signature=chunk.item.id,
+                    )
                 elif isinstance(chunk.item, responses.ResponseOutputMessage):
                     pass
                 else:
@@ -940,6 +952,13 @@ async def _get_event_iterator(self) -> AsyncIterator[ModelResponseStreamEvent]:
             elif isinstance(chunk, responses.ResponseTextDeltaEvent):
                 yield self._parts_manager.handle_text_delta(vendor_part_id=chunk.content_index, content=chunk.delta)
 
+            elif isinstance(chunk, responses.ResponseReasoningSummaryTextDeltaEvent):
+                yield self._parts_manager.handle_thinking_delta(
+                    vendor_part_id=chunk.item_id,
+                    content=chunk.delta,
+                    signature=chunk.item_id,
+                )
+
             elif isinstance(chunk, responses.ResponseTextDoneEvent):
                 pass  # there's nothing we need to do here
 

pydantic_ai_slim/pyproject.toml

@@ -56,7 +56,7 @@ dependencies = [
 # WARNING if you add optional groups, please update docs/install.md
 logfire = ["logfire>=3.11.0"]
 # Models
-openai = ["openai>=1.75.0"]
+openai = ["openai>=1.76.0"]
 cohere = ["cohere>=5.13.11; platform_system != 'Emscripten'"]
 vertexai = ["google-auth>=2.36.0", "requests>=2.32.3"]
 anthropic = ["anthropic>=0.49.0"]