pass container id back

Author: mattbrandman

pydantic_ai_slim/pydantic_ai/models/anthropic.py

@@ -74,6 +74,7 @@
         BetaCodeExecutionToolResultBlockContent,
         BetaCodeExecutionToolResultBlockParam,
         BetaCodeExecutionToolResultBlockParamContentParam,
+        BetaContainerParams,
         BetaContentBlock,
         BetaContentBlockParam,
         BetaImageBlockParam,
@@ -200,6 +201,16 @@ class AnthropicModelSettings(ModelSettings, total=False):
     See https://docs.anthropic.com/en/docs/build-with-claude/prompt-caching for more information.
     """
 
+    anthropic_container: BetaContainerParams | Literal[False]
+    """Container configuration for multi-turn conversations.
+
+    By default, if previous messages contain a container_id (from a prior response),
+    it will be reused automatically.
+
+    Set to `False` to force a fresh container (ignore any container_id from history).
+    Set to a dict (e.g. `{'id': 'container_xxx'}`) to explicitly specify a container.
+    """
+
 
 @dataclass(init=False)
 class AnthropicModel(Model):
@@ -385,6 +396,7 @@ async def _messages_create(
         output_format = self._native_output_format(model_request_parameters)
         betas, extra_headers = self._get_betas_and_extra_headers(tools, model_request_parameters, model_settings)
         betas.update(builtin_tool_betas)
+        container = self._get_container(messages, model_settings)
         try:
             return await self.client.beta.messages.create(
                 max_tokens=model_settings.get('max_tokens', 4096),
@@ -403,6 +415,7 @@ async def _messages_create(
                 top_p=model_settings.get('top_p', OMIT),
                 timeout=model_settings.get('timeout', NOT_GIVEN),
                 metadata=model_settings.get('anthropic_metadata', OMIT),
+                container=container or OMIT,
                 extra_headers=extra_headers,
                 extra_body=model_settings.get('extra_body'),
             )
@@ -439,6 +452,18 @@ def _get_betas_and_extra_headers(
 
         return betas, extra_headers
 
+    def _get_container(
+        self, messages: list[ModelMessage], model_settings: AnthropicModelSettings
+    ) -> BetaContainerParams | None:
+        """Get container config for the API request."""
+        if (container := model_settings.get('anthropic_container')) is not None:
+            return None if container is False else container
+        for m in reversed(messages):
+            if isinstance(m, ModelResponse) and m.provider_details:
+                if cid := m.provider_details.get('container_id'):
+                    return BetaContainerParams(id=cid)
+        return None
+
     async def _messages_count_tokens(
         self,
         messages: list[ModelMessage],
@@ -526,6 +551,9 @@ def _process_response(self, response: BetaMessage) -> ModelResponse:
         if raw_finish_reason := response.stop_reason:  # pragma: no branch
             provider_details = {'finish_reason': raw_finish_reason}
             finish_reason = _FINISH_REASON_MAP.get(raw_finish_reason)
+        if response.container:
+            provider_details = provider_details or {}
+            provider_details['container_id'] = response.container.id
 
         return ModelResponse(
             parts=items,
@@ -1125,6 +1153,9 @@ async def _get_event_iterator(self) -> AsyncIterator[ModelResponseStreamEvent]:
             if isinstance(event, BetaRawMessageStartEvent):
                 self._usage = _map_usage(event, self._provider_name, self._provider_url, self._model_name)
                 self.provider_response_id = event.message.id
+                if event.message.container:
+                    self.provider_details = self.provider_details or {}
+                    self.provider_details['container_id'] = event.message.container.id
 
             elif isinstance(event, BetaRawContentBlockStartEvent):
                 current_block = event.content_block
@@ -1239,7 +1270,7 @@ async def _get_event_iterator(self) -> AsyncIterator[ModelResponseStreamEvent]:
             elif isinstance(event, BetaRawMessageDeltaEvent):
                 self._usage = _map_usage(event, self._provider_name, self._provider_url, self._model_name, self._usage)
                 if raw_finish_reason := event.delta.stop_reason:  # pragma: no branch
-                    self.provider_details = {'finish_reason': raw_finish_reason}
+                    self.provider_details = {**(self.provider_details or {}), 'finish_reason': raw_finish_reason}
                     self.finish_reason = _FINISH_REASON_MAP.get(raw_finish_reason)
 
             elif isinstance(event, BetaRawContentBlockStopEvent):  # pragma: no branch

tests/models/test_anthropic.py

@@ -5512,7 +5512,7 @@ async def test_anthropic_code_execution_tool(allow_model_requests: None, anthrop
                 model_name='claude-sonnet-4-20250514',
                 timestamp=IsDatetime(),
                 provider_name='anthropic',
-                provider_details={'finish_reason': 'end_turn'},
+                provider_details={'finish_reason': 'end_turn', 'container_id': 'container_011CTCwceSoRxi8Pf16Fb7Tn'},
                 provider_response_id='msg_018bVTPr9khzuds31rFDuqW4',
                 finish_reason='stop',
                 run_id=IsStr(),
@@ -5579,7 +5579,7 @@ async def test_anthropic_code_execution_tool(allow_model_requests: None, anthrop
                 model_name='claude-sonnet-4-20250514',
                 timestamp=IsDatetime(),
                 provider_name='anthropic',
-                provider_details={'finish_reason': 'end_turn'},
+                provider_details={'finish_reason': 'end_turn', 'container_id': 'container_011CTCwdXe48NC7LaX3rxQ4d'},
                 provider_response_id='msg_01VngRFBcNddwrYQoKUmdePY',
                 finish_reason='stop',
                 run_id=IsStr(),