fix: round-trip instruction request parts

pydantic_ai_slim/pydantic_ai/_enqueue.py

@@ -12,6 +12,7 @@
 
 from .exceptions import UserError
 from .messages import (
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelRequestPart,
@@ -96,7 +97,8 @@ def flush_request() -> None:
             flush_request()
             messages.append(item)
         elif isinstance(
-            item, (SystemPromptPart, UserPromptPart, ToolReturnPart, RetryPromptPart, ToolSearchReturnPart)
+            item,
+            (SystemPromptPart, InstructionPart, UserPromptPart, ToolReturnPart, RetryPromptPart, ToolSearchReturnPart),
         ):
             flush_content()
             parts.append(item)

pydantic_ai_slim/pydantic_ai/messages.py

@@ -1538,6 +1538,15 @@ def sorted(parts: Sequence[InstructionPart]) -> list[InstructionPart]:
         """Sort instruction parts with static (`dynamic=False`) before dynamic, preserving relative order."""
         return sorted(parts, key=lambda p: p.dynamic)
 
+    def otel_event(self, settings: InstrumentationSettings) -> LogRecord:
+        return LogRecord(
+            attributes={'event.name': 'gen_ai.system.message'},
+            body={'role': 'system', **({'content': self.content} if settings.include_content else {})},
+        )
+
+    def otel_message_parts(self, settings: InstrumentationSettings) -> list[_otel_messages.MessagePart]:
+        return [_otel_messages.TextPart(type='text', **{'content': self.content} if settings.include_content else {})]
+
     __repr__ = _utils.dataclasses_no_defaults_repr
 
 
@@ -2022,6 +2031,7 @@ def _model_request_part_discriminator(v: Any) -> str | None:
 
 ModelRequestPart = Annotated[
     Annotated[SystemPromptPart, pydantic.Tag('system-prompt')]
+    | Annotated[InstructionPart, pydantic.Tag('instruction')]
     | Annotated[UserPromptPart, pydantic.Tag('user-prompt')]
     | Annotated[ToolSearchReturnPart, pydantic.Tag('tool-search-return')]
     | Annotated[ToolReturnPart, pydantic.Tag('tool-return')]

pydantic_ai_slim/pydantic_ai/models/__init__.py

@@ -40,6 +40,7 @@
     InstructionPart,
     ModelMessage,
     ModelRequest,
+    ModelRequestPart,
     ModelResponse,
     ModelResponsePart,
     ModelResponseState,
@@ -1823,13 +1824,17 @@ def _wrap_non_leading_system_prompts(messages: list[ModelMessage]) -> list[Model
     new_messages: list[ModelMessage] = list(messages[: first_request_idx + 1])
     changed = False
     for msg in messages[first_request_idx + 1 :]:
-        if isinstance(msg, ModelRequest) and any(isinstance(p, SystemPromptPart) for p in msg.parts):
-            new_parts = [
-                UserPromptPart(content=f'<system>{part.content}</system>', timestamp=part.timestamp)
-                if isinstance(part, SystemPromptPart)
-                else part
-                for part in msg.parts
-            ]
+        if isinstance(msg, ModelRequest) and any(isinstance(p, SystemPromptPart | InstructionPart) for p in msg.parts):
+            new_parts: list[ModelRequestPart] = []
+            for part in msg.parts:
+                if isinstance(part, SystemPromptPart):
+                    new_parts.append(
+                        UserPromptPart(content=f'<system>{part.content}</system>', timestamp=part.timestamp)
+                    )
+                elif isinstance(part, InstructionPart):
+                    new_parts.append(UserPromptPart(content=f'<system>{part.content}</system>'))
+                else:
+                    new_parts.append(part)
             new_messages.append(replace(msg, parts=new_parts))
             changed = True
         else:

pydantic_ai_slim/pydantic_ai/models/bedrock.py

@@ -34,6 +34,7 @@
     FilePart,
     FinishReason,
     ImageUrl,
+    InstructionPart,
     ModelMessage,
     ModelProfileSpec,
     ModelRequest,
@@ -919,7 +920,7 @@ async def _map_messages(  # noqa: C901
         for message in messages:
             if isinstance(message, ModelRequest):
                 for part in message.parts:
-                    if isinstance(part, SystemPromptPart):
+                    if isinstance(part, SystemPromptPart | InstructionPart):
                         if part.content:  # pragma: no branch
                             system_prompt.append({'text': part.content})
                     elif isinstance(part, UserPromptPart):

pydantic_ai_slim/pydantic_ai/models/cohere.py

@@ -15,6 +15,7 @@
     CompactionPart,
     FilePart,
     FinishReason,
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelResponse,
@@ -309,7 +310,7 @@ def _map_tool_definition(f: ToolDefinition) -> ToolV2:
     @classmethod
     def _map_user_message(cls, message: ModelRequest) -> Iterable[ChatMessageV2]:
         for part in message.parts:
-            if isinstance(part, SystemPromptPart):
+            if isinstance(part, SystemPromptPart | InstructionPart):
                 yield SystemChatMessageV2(role='system', content=part.content)
             elif isinstance(part, UserPromptPart):
                 if isinstance(part.content, str):

pydantic_ai_slim/pydantic_ai/models/function.py

@@ -19,6 +19,7 @@
     BinaryContent,
     CompactionPart,
     FilePart,
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelResponse,
@@ -394,7 +395,7 @@ def _estimate_usage(messages: Iterable[ModelMessage]) -> usage.RequestUsage:
     for message in messages:
         if isinstance(message, ModelRequest):
             for part in message.parts:
-                if isinstance(part, SystemPromptPart | UserPromptPart):
+                if isinstance(part, SystemPromptPart | InstructionPart | UserPromptPart):
                     request_tokens += _estimate_string_tokens(part.content)
                 elif isinstance(part, ToolReturnPart):
                     request_tokens += _estimate_string_tokens(part.model_response_str())

pydantic_ai_slim/pydantic_ai/models/gemini.py

@@ -31,6 +31,7 @@
     CompactionPart,
     FilePart,
     FileUrl,
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelResponse,
@@ -350,7 +351,7 @@ async def _message_to_gemini_content(
                 message_parts: list[_GeminiPartUnion] = []
 
                 for part in m.parts:
-                    if isinstance(part, SystemPromptPart):
+                    if isinstance(part, SystemPromptPart | InstructionPart):
                         sys_prompt_parts.append(_GeminiTextPart(text=part.content))
                     elif isinstance(part, UserPromptPart):
                         message_parts.extend(await self._map_user_prompt(part))

pydantic_ai_slim/pydantic_ai/models/google.py

@@ -24,6 +24,7 @@
     FilePart,
     FileUrl,
     FinishReason,
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelResponse,
@@ -1020,7 +1021,7 @@ async def _map_messages(  # noqa: C901
                 message_parts: list[PartDict] = []
 
                 for part in m.parts:
-                    if isinstance(part, SystemPromptPart):
+                    if isinstance(part, SystemPromptPart | InstructionPart):
                         system_parts.append({'text': part.content})
                     elif isinstance(part, UserPromptPart):
                         message_parts.extend(await self._map_user_prompt(part))

pydantic_ai_slim/pydantic_ai/models/groq.py

@@ -25,6 +25,7 @@
     FilePart,
     FinishReason,
     ImageUrl,
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelResponse,
@@ -542,7 +543,7 @@ def _map_json_schema(self, o: OutputObjectDefinition) -> chat.completion_create_
     async def _map_user_message(self, message: ModelRequest) -> AsyncIterable[chat.ChatCompletionMessageParam]:
         file_content: list[UserContent] = []
         for part in message.parts:
-            if isinstance(part, SystemPromptPart):
+            if isinstance(part, SystemPromptPart | InstructionPart):
                 yield chat.ChatCompletionSystemMessageParam(role='system', content=part.content)
             elif isinstance(part, UserPromptPart):
                 yield await self._map_user_prompt(part)

pydantic_ai_slim/pydantic_ai/models/huggingface.py

@@ -21,6 +21,7 @@
     FilePart,
     FinishReason,
     ImageUrl,
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelResponse,
@@ -455,7 +456,7 @@ async def _map_user_message(
         self, message: ModelRequest
     ) -> AsyncIterable[ChatCompletionInputMessage | ChatCompletionOutputMessage]:
         for part in message.parts:
-            if isinstance(part, SystemPromptPart):
+            if isinstance(part, SystemPromptPart | InstructionPart):
                 yield ChatCompletionInputMessage.parse_obj_as_instance({'role': 'system', 'content': part.content})  # type: ignore
             elif isinstance(part, UserPromptPart):
                 yield await self._map_user_prompt(part)

pydantic_ai_slim/pydantic_ai/models/instrumented.py

@@ -32,6 +32,7 @@
 from .. import _otel_messages
 from .._run_context import RunContext
 from ..messages import (
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelResponse,
@@ -221,7 +222,9 @@ def messages_to_otel_messages(self, messages: list[ModelMessage]) -> list[_otel_
         result: list[_otel_messages.ChatMessage] = []
         for message in messages:
             if isinstance(message, ModelRequest):
-                for is_system, group in itertools.groupby(message.parts, key=lambda p: isinstance(p, SystemPromptPart)):
+                for is_system, group in itertools.groupby(
+                    message.parts, key=lambda p: isinstance(p, SystemPromptPart | InstructionPart)
+                ):
                     message_parts: list[_otel_messages.MessagePart] = []
                     for part in group:
                         if hasattr(part, 'otel_message_parts'):

pydantic_ai_slim/pydantic_ai/models/mistral.py

@@ -23,6 +23,7 @@
     FilePart,
     FinishReason,
     ImageUrl,
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelResponse,
@@ -544,7 +545,7 @@ def _get_timeout_ms(timeout: Timeout | float | None) -> int | None:
     async def _map_user_message(self, message: ModelRequest) -> AsyncIterable[MistralMessages]:
         file_content: list[UserContent] = []
         for part in message.parts:
-            if isinstance(part, SystemPromptPart):
+            if isinstance(part, SystemPromptPart | InstructionPart):
                 yield MistralSystemMessage(content=part.content)
             elif isinstance(part, UserPromptPart):
                 yield await self._map_user_prompt(part)

pydantic_ai_slim/pydantic_ai/models/openai.py

@@ -40,6 +40,7 @@
     FilePart,
     FinishReason,
     ImageUrl,
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelResponse,
@@ -1511,7 +1512,7 @@ def _map_tool_definition(self, f: ToolDefinition, model_settings: ModelSettings)
     async def _map_user_message(self, message: ModelRequest) -> AsyncIterable[chat.ChatCompletionMessageParam]:
         file_content: list[UserContent] = []
         for part in message.parts:
-            if isinstance(part, SystemPromptPart):
+            if isinstance(part, SystemPromptPart | InstructionPart):
                 system_prompt_role = OpenAIModelProfile.from_profile(self.profile).openai_system_prompt_role
                 if system_prompt_role == 'developer':
                     yield chat.ChatCompletionDeveloperMessageParam(role='developer', content=part.content)
@@ -2718,7 +2719,7 @@ async def _map_messages(  # noqa: C901
         for message in messages:
             if isinstance(message, ModelRequest):
                 for part in message.parts:
-                    if isinstance(part, SystemPromptPart):
+                    if isinstance(part, SystemPromptPart | InstructionPart):
                         openai_messages.append(
                             responses.EasyInputMessageParam(
                                 role=profile.openai_system_prompt_role or 'system', content=part.content

pydantic_ai_slim/pydantic_ai/models/outlines.py

@@ -24,6 +24,7 @@
     CompactionPart,
     FilePart,
     ImageUrl,
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelResponse,
@@ -448,7 +449,7 @@ async def _format_prompt(  # noqa: C901
         for message in messages:
             if isinstance(message, ModelRequest):
                 for part in message.parts:
-                    if isinstance(part, SystemPromptPart):
+                    if isinstance(part, SystemPromptPart | InstructionPart):
                         chat.add_system_message(part.content)
                     elif isinstance(part, UserPromptPart):
                         if isinstance(part.content, str):

pydantic_ai_slim/pydantic_ai/models/xai.py

@@ -24,6 +24,7 @@
     FilePart,
     FinishReason,
     ImageUrl,
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelRequestPart,
@@ -314,7 +315,7 @@ async def _map_request_parts(
         tool_results: list[ToolReturnPart | RetryPromptPart] = []
 
         for part in parts:
-            if isinstance(part, SystemPromptPart):
+            if isinstance(part, SystemPromptPart | InstructionPart):
                 xai_messages.append(system(part.content))
             elif isinstance(part, UserPromptPart):
                 if user_msg := await self._map_user_prompt(part):

pydantic_ai_slim/pydantic_ai/ui/_adapter.py

@@ -30,6 +30,7 @@
     BaseToolReturnPart,
     FileUrl,
     ForceDownloadMode,
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelRequestPart,
@@ -440,7 +441,7 @@ def _sanitize_request_parts(
         stripped_system_prompt = False
         new_parts: list[ModelRequestPart] = []
         for part in parts:
-            if strip_system_prompt and isinstance(part, SystemPromptPart):
+            if strip_system_prompt and isinstance(part, SystemPromptPart | InstructionPart):
                 stripped_system_prompt = True
                 continue
             if isinstance(part, UserPromptPart) and not isinstance(part.content, str):

pydantic_ai_slim/pydantic_ai/ui/ag_ui/_adapter.py

@@ -28,6 +28,7 @@
     FilePart,
     ForceDownloadMode,
     ImageUrl,
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelResponse,
@@ -511,7 +512,7 @@ def _dump_request_parts(
         ] = []
 
         for part in msg.parts:
-            if isinstance(part, SystemPromptPart):
+            if isinstance(part, SystemPromptPart | InstructionPart):
                 system_content.append(part.content)
             elif isinstance(part, UserPromptPart):
                 if isinstance(part.content, str):

pydantic_ai_slim/pydantic_ai/ui/vercel_ai/_adapter.py

@@ -24,6 +24,7 @@
     FilePart,
     ForceDownloadMode,
     ImageUrl,
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelResponse,
@@ -517,7 +518,7 @@ def _dump_request_message(msg: ModelRequest) -> tuple[list[UIMessagePart], list[
         user_ui_parts: list[UIMessagePart] = []
 
         for part in msg.parts:
-            if isinstance(part, SystemPromptPart):
+            if isinstance(part, SystemPromptPart | InstructionPart):
                 system_ui_parts.append(TextUIPart(text=part.content, state='done'))
             elif isinstance(part, UserPromptPart):
                 user_ui_parts.extend(_convert_user_prompt_part(part))

tests/models/test_model.py

@@ -8,6 +8,7 @@
 from pydantic_ai import UserError
 from pydantic_ai._warnings import PydanticAIDeprecationWarning
 from pydantic_ai.messages import (
+    InstructionPart,
     ModelMessage,
     ModelRequest,
     ModelResponse,
@@ -461,6 +462,19 @@ def _request_parts(messages: list[ModelMessage]) -> list[list[tuple[str, object]
             ],
             id='wraps-multiple-non-leading-system-prompts',
         ),
+        pytest.param(
+            False,
+            [
+                ModelRequest(parts=[UserPromptPart(content='hi')]),
+                ModelResponse(parts=[TextPart(content='hello')]),
+                ModelRequest(parts=[InstructionPart(content='Use a short answer.'), UserPromptPart(content='ok?')]),
+            ],
+            [
+                [('UserPromptPart', 'hi')],
+                [('UserPromptPart', '<system>Use a short answer.</system>'), ('UserPromptPart', 'ok?')],
+            ],
+            id='wraps-non-leading-instruction-part',
+        ),
         pytest.param(
             False,
             [