Handle model response timestamps in milliseconds rather than seconds (#1937)

Author: DouweM

pydantic_ai_slim/pydantic_ai/_utils.py

@@ -12,7 +12,7 @@
 from typing import TYPE_CHECKING, Any, Callable, Generic, TypeVar, Union
 
 from anyio.to_thread import run_sync
-from pydantic import BaseModel
+from pydantic import BaseModel, TypeAdapter
 from pydantic.json_schema import JsonSchemaValue
 from typing_extensions import ParamSpec, TypeAlias, TypeGuard, is_typeddict
 
@@ -298,3 +298,7 @@ def dataclasses_no_defaults_repr(self: Any) -> str:
         f'{f.name}={getattr(self, f.name)!r}' for f in fields(self) if f.repr and getattr(self, f.name) != f.default
     )
     return f'{self.__class__.__qualname__}({", ".join(kv_pairs)})'
+
+
+def number_to_datetime(x: int | float) -> datetime:
+    return TypeAdapter(datetime).validate_python(x)

pydantic_ai_slim/pydantic_ai/models/groq.py

@@ -4,13 +4,13 @@
 from collections.abc import AsyncIterable, AsyncIterator, Iterable
 from contextlib import asynccontextmanager
 from dataclasses import dataclass, field
-from datetime import datetime, timezone
+from datetime import datetime
 from typing import Literal, Union, cast, overload
 
 from typing_extensions import assert_never
 
 from .. import ModelHTTPError, UnexpectedModelBehavior, _utils, usage
-from .._utils import guard_tool_call_id as _guard_tool_call_id
+from .._utils import guard_tool_call_id as _guard_tool_call_id, number_to_datetime
 from ..messages import (
     BinaryContent,
     DocumentUrl,
@@ -246,7 +246,7 @@ async def _completions_create(
 
     def _process_response(self, response: chat.ChatCompletion) -> ModelResponse:
         """Process a non-streamed response, and prepare a message to return."""
-        timestamp = datetime.fromtimestamp(response.created, tz=timezone.utc)
+        timestamp = number_to_datetime(response.created)
         choice = response.choices[0]
         items: list[ModelResponsePart] = []
         if choice.message.content is not None:
@@ -270,7 +270,7 @@ async def _process_streamed_response(self, response: AsyncStream[chat.ChatComple
         return GroqStreamedResponse(
             _response=peekable_response,
             _model_name=self._model_name,
-            _timestamp=datetime.fromtimestamp(first_chunk.created, tz=timezone.utc),
+            _timestamp=number_to_datetime(first_chunk.created),
         )
 
     def _get_tools(self, model_request_parameters: ModelRequestParameters) -> list[chat.ChatCompletionToolParam]:

pydantic_ai_slim/pydantic_ai/models/mistral.py

@@ -4,15 +4,15 @@
 from collections.abc import AsyncIterable, AsyncIterator, Iterable
 from contextlib import asynccontextmanager
 from dataclasses import dataclass, field
-from datetime import datetime, timezone
+from datetime import datetime
 from typing import Any, Literal, Union, cast
 
 import pydantic_core
 from httpx import Timeout
 from typing_extensions import assert_never
 
 from .. import ModelHTTPError, UnexpectedModelBehavior, _utils
-from .._utils import generate_tool_call_id as _generate_tool_call_id, now_utc as _now_utc
+from .._utils import generate_tool_call_id as _generate_tool_call_id, now_utc as _now_utc, number_to_datetime
 from ..messages import (
     BinaryContent,
     DocumentUrl,
@@ -312,7 +312,7 @@ def _process_response(self, response: MistralChatCompletionResponse) -> ModelRes
         assert response.choices, 'Unexpected empty response choice.'
 
         if response.created:
-            timestamp = datetime.fromtimestamp(response.created, tz=timezone.utc)
+            timestamp = number_to_datetime(response.created)
         else:
             timestamp = _now_utc()
 
@@ -347,9 +347,9 @@ async def _process_streamed_response(
             )
 
         if first_chunk.data.created:
-            timestamp = datetime.fromtimestamp(first_chunk.data.created, tz=timezone.utc)
+            timestamp = number_to_datetime(first_chunk.data.created)
         else:
-            timestamp = datetime.now(tz=timezone.utc)
+            timestamp = _now_utc()
 
         return MistralStreamedResponse(
             _response=peekable_response,

pydantic_ai_slim/pydantic_ai/models/openai.py

@@ -5,7 +5,7 @@
 from collections.abc import AsyncIterable, AsyncIterator, Sequence
 from contextlib import asynccontextmanager
 from dataclasses import dataclass, field
-from datetime import datetime, timezone
+from datetime import datetime
 from typing import Any, Literal, Union, cast, overload
 
 from typing_extensions import assert_never
@@ -14,7 +14,7 @@
 from pydantic_ai.providers import Provider, infer_provider
 
 from .. import ModelHTTPError, UnexpectedModelBehavior, _utils, usage
-from .._utils import guard_tool_call_id as _guard_tool_call_id
+from .._utils import guard_tool_call_id as _guard_tool_call_id, number_to_datetime
 from ..messages import (
     AudioUrl,
     BinaryContent,
@@ -308,7 +308,7 @@ async def _completions_create(
 
     def _process_response(self, response: chat.ChatCompletion) -> ModelResponse:
         """Process a non-streamed response, and prepare a message to return."""
-        timestamp = datetime.fromtimestamp(response.created, tz=timezone.utc)
+        timestamp = number_to_datetime(response.created)
         choice = response.choices[0]
         items: list[ModelResponsePart] = []
         vendor_details: dict[str, Any] | None = None
@@ -358,7 +358,7 @@ async def _process_streamed_response(self, response: AsyncStream[ChatCompletionC
         return OpenAIStreamedResponse(
             _model_name=self._model_name,
             _response=peekable_response,
-            _timestamp=datetime.fromtimestamp(first_chunk.created, tz=timezone.utc),
+            _timestamp=number_to_datetime(first_chunk.created),
         )
 
     def _get_tools(self, model_request_parameters: ModelRequestParameters) -> list[chat.ChatCompletionToolParam]:
@@ -593,7 +593,7 @@ async def request_stream(
 
     def _process_response(self, response: responses.Response) -> ModelResponse:
         """Process a non-streamed response, and prepare a message to return."""
-        timestamp = datetime.fromtimestamp(response.created_at, tz=timezone.utc)
+        timestamp = number_to_datetime(response.created_at)
         items: list[ModelResponsePart] = []
         items.append(TextPart(response.output_text))
         for item in response.output:
@@ -614,7 +614,7 @@ async def _process_streamed_response(
         return OpenAIResponsesStreamedResponse(
             _model_name=self._model_name,
             _response=peekable_response,
-            _timestamp=datetime.fromtimestamp(first_chunk.response.created_at, tz=timezone.utc),
+            _timestamp=number_to_datetime(first_chunk.response.created_at),
         )
 
     @overload

tests/models/test_openai.py

@@ -1732,3 +1732,20 @@ def get_current_time() -> str:
 
     response = await agent.run('What is the current time?')
     assert response.output == snapshot('The current time is Noon.')
+
+
+def test_openai_response_timestamp_milliseconds(allow_model_requests: None):
+    c = completion_message(
+        ChatCompletionMessage(content='world', role='assistant'),
+    )
+    # Some models on OpenRouter return timestamps in milliseconds rather than seconds
+    # https://github.com/pydantic/pydantic-ai/issues/1877
+    c.created = 1748747268000
+
+    mock_client = MockOpenAI.create_mock(c)
+    m = OpenAIModel('gpt-4o', provider=OpenAIProvider(openai_client=mock_client))
+    agent = Agent(m)
+
+    result = agent.run_sync('Hello')
+    response = cast(ModelResponse, result.all_messages()[-1])
+    assert response.timestamp == snapshot(datetime(2025, 6, 1, 3, 7, 48, tzinfo=timezone.utc))