More fixes to reasoning

Author: mwildehahn

pydantic_ai_slim/pydantic_ai/_parts_manager.py

@@ -111,7 +111,7 @@ def handle_text_delta(
         if existing_text_part_and_index is None:
             # There is no existing text part that should be updated, so create a new one
             new_part_index = len(self._parts)
-            part = TextPart(content=content)
+            part = TextPart(id=vendor_part_id, content=content)
             if vendor_part_id is not None:
                 self._vendor_id_to_part_index[vendor_part_id] = new_part_index
             self._parts.append(part)

pydantic_ai_slim/pydantic_ai/messages.py

@@ -486,6 +486,8 @@ class TextPart:
     part_kind: Literal['text'] = 'text'
     """Part type identifier, this is available on all parts as a discriminator."""
 
+    id: str | None = None
+
     def has_content(self) -> bool:
         """Return `True` if the text content is non-empty."""
         return bool(self.content)
@@ -504,6 +506,8 @@ class ThinkingPart:
     part_kind: Literal['thinking'] = 'thinking'
     """Part type identifier, this is available on all parts as a discriminator."""
 
+    id: str | None = None
+
     def has_content(self) -> bool:
         """Return `True` if the thinking content is non-empty."""
         return bool(self.content)

pydantic_ai_slim/pydantic_ai/models/openai.py

@@ -727,7 +727,21 @@ async def _map_messages(
             elif isinstance(message, ModelResponse):
                 for item in message.parts:
                     if isinstance(item, TextPart):
-                        openai_messages.append(responses.EasyInputMessageParam(role='assistant', content=item.content))
+                        openai_messages.append(
+                            responses.ResponseOutputMessageParam(
+                                id=item.id or '',
+                                role='assistant',
+                                content=[
+                                    responses.ResponseOutputTextParam(
+                                        text=item.content,
+                                        type='output_text',
+                                        annotations=[],
+                                    )
+                                ],
+                                status='completed',
+                                type='message',
+                            )
+                        )
                     elif isinstance(item, ToolCallPart):
                         openai_messages.append(self._map_tool_call(item))
                     elif isinstance(item, ThinkingPart):
@@ -952,7 +966,7 @@ async def _get_event_iterator(self) -> AsyncIterator[ModelResponseStreamEvent]:
                 pass
 
             elif isinstance(chunk, responses.ResponseTextDeltaEvent):
-                yield self._parts_manager.handle_text_delta(vendor_part_id=chunk.content_index, content=chunk.delta)
+                yield self._parts_manager.handle_text_delta(vendor_part_id=chunk.item_id, content=chunk.delta)
 
             elif isinstance(chunk, responses.ResponseReasoningSummaryTextDeltaEvent):
                 yield self._parts_manager.handle_thinking_delta(