mcp-run-python

from __future__ import annotations import functools import typing from collections.abc import AsyncIterator, Iterable, Iterator, Mapping from contextlib import asynccontextmanager from dataclasses import dataclass, field from datetime import datetime from itertools import count from typing import TYPE_CHECKING, Any, Generic, Literal, cast, overload import anyio import anyio.to_thread from typing_extensions import ParamSpec, assert_never from pydantic_ai import ( AudioUrl, BinaryContent, BuiltinToolCallPart, BuiltinToolReturnPart, DocumentUrl, FinishReason, ImageUrl, ModelMessage, ModelProfileSpec, ModelRequest, ModelResponse, ModelResponsePart, ModelResponseStreamEvent, RetryPromptPart, SystemPromptPart, TextPart, ThinkingPart, ToolCallPart, ToolReturnPart, UserPromptPart, VideoUrl, _utils, usage, ) from pydantic_ai._run_context import RunContext from pydantic_ai.exceptions import UserError from pydantic_ai.models import Model, ModelRequestParameters, StreamedResponse, download_item from pydantic_ai.providers import Provider, infer_provider from pydantic_ai.providers.bedrock import BedrockModelProfile from pydantic_ai.settings import ModelSettings from pydantic_ai.tools import ToolDefinition if TYPE_CHECKING: from botocore.client import BaseClient from botocore.eventstream import EventStream from mypy_boto3_bedrock_runtime import BedrockRuntimeClient from mypy_boto3_bedrock_runtime.literals import StopReasonType from mypy_boto3_bedrock_runtime.type_defs import ( ContentBlockOutputTypeDef, ContentBlockUnionTypeDef, ConverseRequestTypeDef, ConverseResponseTypeDef, ConverseStreamMetadataEventTypeDef, ConverseStreamOutputTypeDef, ConverseStreamResponseTypeDef, DocumentBlockTypeDef, GuardrailConfigurationTypeDef, ImageBlockTypeDef, InferenceConfigurationTypeDef, MessageUnionTypeDef, PerformanceConfigurationTypeDef, PromptVariableValuesTypeDef, ReasoningContentBlockOutputTypeDef, SystemContentBlockTypeDef, ToolChoiceTypeDef, ToolConfigurationTypeDef, ToolSpecificationTypeDef, ToolTypeDef, VideoBlockTypeDef, ) LatestBedrockModelNames = Literal[ 'amazon.titan-tg1-large', 'amazon.titan-text-lite-v1', 'amazon.titan-text-express-v1', 'us.amazon.nova-pro-v1:0', 'us.amazon.nova-lite-v1:0', 'us.amazon.nova-micro-v1:0', 'anthropic.claude-3-5-sonnet-20241022-v2:0', 'us.anthropic.claude-3-5-sonnet-20241022-v2:0', 'anthropic.claude-3-5-haiku-20241022-v1:0', 'us.anthropic.claude-3-5-haiku-20241022-v1:0', 'anthropic.claude-instant-v1', 'anthropic.claude-v2:1', 'anthropic.claude-v2', 'anthropic.claude-3-sonnet-20240229-v1:0', 'us.anthropic.claude-3-sonnet-20240229-v1:0', 'anthropic.claude-3-haiku-20240307-v1:0', 'us.anthropic.claude-3-haiku-20240307-v1:0', 'anthropic.claude-3-opus-20240229-v1:0', 'us.anthropic.claude-3-opus-20240229-v1:0', 'anthropic.claude-3-5-sonnet-20240620-v1:0', 'us.anthropic.claude-3-5-sonnet-20240620-v1:0', 'anthropic.claude-3-7-sonnet-20250219-v1:0', 'us.anthropic.claude-3-7-sonnet-20250219-v1:0', 'anthropic.claude-opus-4-20250514-v1:0', 'us.anthropic.claude-opus-4-20250514-v1:0', 'anthropic.claude-sonnet-4-20250514-v1:0', 'us.anthropic.claude-sonnet-4-20250514-v1:0', 'cohere.command-text-v14', 'cohere.command-r-v1:0', 'cohere.command-r-plus-v1:0', 'cohere.command-light-text-v14', 'meta.llama3-8b-instruct-v1:0', 'meta.llama3-70b-instruct-v1:0', 'meta.llama3-1-8b-instruct-v1:0', 'us.meta.llama3-1-8b-instruct-v1:0', 'meta.llama3-1-70b-instruct-v1:0', 'us.meta.llama3-1-70b-instruct-v1:0', 'meta.llama3-1-405b-instruct-v1:0', 'us.meta.llama3-2-11b-instruct-v1:0', 'us.meta.llama3-2-90b-instruct-v1:0', 'us.meta.llama3-2-1b-instruct-v1:0', 'us.meta.llama3-2-3b-instruct-v1:0', 'us.meta.llama3-3-70b-instruct-v1:0', 'mistral.mistral-7b-instruct-v0:2', 'mistral.mixtral-8x7b-instruct-v0:1', 'mistral.mistral-large-2402-v1:0', 'mistral.mistral-large-2407-v1:0', ] """Latest Bedrock models.""" BedrockModelName = str | LatestBedrockModelNames """Possible Bedrock model names. Since Bedrock supports a variety of date-stamped models, we explicitly list the latest models but allow any name in the type hints. See [the Bedrock docs](https://docs.aws.amazon.com/bedrock/latest/userguide/models-supported.html) for a full list. """ P = ParamSpec('P') T = typing.TypeVar('T') _FINISH_REASON_MAP: dict[StopReasonType, FinishReason] = { 'content_filtered': 'content_filter', 'end_turn': 'stop', 'guardrail_intervened': 'content_filter', 'max_tokens': 'length', 'stop_sequence': 'stop', 'tool_use': 'tool_call', } class BedrockModelSettings(ModelSettings, total=False): """Settings for Bedrock models. See [the Bedrock Converse API docs](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_runtime_Converse.html#API_runtime_Converse_RequestSyntax) for a full list. See [the boto3 implementation](https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/bedrock-runtime/client/converse.html) of the Bedrock Converse API. """ # ALL FIELDS MUST BE `bedrock_` PREFIXED SO YOU CAN MERGE THEM WITH OTHER MODELS. bedrock_guardrail_config: GuardrailConfigurationTypeDef """Content moderation and safety settings for Bedrock API requests. See more about it on <https://docs.aws.amazon.com/bedrock/latest/APIReference/API_runtime_GuardrailConfiguration.html>. """ bedrock_performance_configuration: PerformanceConfigurationTypeDef """Performance optimization settings for model inference. See more about it on <https://docs.aws.amazon.com/bedrock/latest/APIReference/API_runtime_PerformanceConfiguration.html>. """ bedrock_request_metadata: dict[str, str] """Additional metadata to attach to Bedrock API requests. See more about it on <https://docs.aws.amazon.com/bedrock/latest/APIReference/API_runtime_Converse.html#API_runtime_Converse_RequestSyntax>. """ bedrock_additional_model_response_fields_paths: list[str] """JSON paths to extract additional fields from model responses. See more about it on <https://docs.aws.amazon.com/bedrock/latest/userguide/model-parameters.html>. """ bedrock_prompt_variables: Mapping[str, PromptVariableValuesTypeDef] """Variables for substitution into prompt templates. See more about it on <https://docs.aws.amazon.com/bedrock/latest/APIReference/API_runtime_PromptVariableValues.html>. """ bedrock_additional_model_requests_fields: Mapping[str, Any] """Additional model-specific parameters to include in requests. See more about it on <https://docs.aws.amazon.com/bedrock/latest/userguide/model-parameters.html>. """ @dataclass(init=False) class BedrockConverseModel(Model): """A model that uses the Bedrock Converse API.""" client: BedrockRuntimeClient _model_name: BedrockModelName = field(repr=False) _provider: Provider[BaseClient] = field(repr=False) def __init__( self, model_name: BedrockModelName, *, provider: Literal['bedrock', 'gateway'] | Provider[BaseClient] = 'bedrock', profile: ModelProfileSpec | None = None, settings: ModelSettings | None = None, ): """Initialize a Bedrock model. Args: model_name: The name of the model to use. model_name: The name of the Bedrock model to use. List of model names available [here](https://docs.aws.amazon.com/bedrock/latest/userguide/models-supported.html). provider: The provider to use for authentication and API access. Can be either the string 'bedrock' or an instance of `Provider[BaseClient]`. If not provided, a new provider will be created using the other parameters. profile: The model profile to use. Defaults to a profile picked by the provider based on the model name. settings: Model-specific settings that will be used as defaults for this model. """ self._model_name = model_name if isinstance(provider, str): provider = infer_provider('gateway/bedrock' if provider == 'gateway' else provider) self._provider = provider self.client = cast('BedrockRuntimeClient', provider.client) super().__init__(settings=settings, profile=profile or provider.model_profile) @property def base_url(self) -> str: return str(self.client.meta.endpoint_url) @property def model_name(self) -> str: """The model name.""" return self._model_name @property def system(self) -> str: """The model provider.""" return self._provider.name def _get_tools(self, model_request_parameters: ModelRequestParameters) -> list[ToolTypeDef]: return [self._map_tool_definition(r) for r in model_request_parameters.tool_defs.values()] @staticmethod def _map_tool_definition(f: ToolDefinition) -> ToolTypeDef: tool_spec: ToolSpecificationTypeDef = {'name': f.name, 'inputSchema': {'json': f.parameters_json_schema}} if f.description: # pragma: no branch tool_spec['description'] = f.description return {'toolSpec': tool_spec} async def request( self, messages: list[ModelMessage], model_settings: ModelSettings | None, model_request_parameters: ModelRequestParameters, ) -> ModelResponse: model_settings, model_request_parameters = self.prepare_request( model_settings, model_request_parameters, ) settings = cast(BedrockModelSettings, model_settings or {}) response = await self._messages_create(messages, False, settings, model_request_parameters) model_response = await self._process_response(response) return model_response @asynccontextmanager async def request_stream( self, messages: list[ModelMessage], model_settings: ModelSettings | None, model_request_parameters: ModelRequestParameters, run_context: RunContext[Any] | None = None, ) -> AsyncIterator[StreamedResponse]: model_settings, model_request_parameters = self.prepare_request( model_settings, model_request_parameters, ) settings = cast(BedrockModelSettings, model_settings or {}) response = await self._messages_create(messages, True, settings, model_request_parameters) yield BedrockStreamedResponse( model_request_parameters=model_request_parameters, _model_name=self.model_name, _event_stream=response['stream'], _provider_name=self._provider.name, _provider_response_id=response.get('ResponseMetadata', {}).get('RequestId', None), ) async def _process_response(self, response: ConverseResponseTypeDef) -> ModelResponse: items: list[ModelResponsePart] = [] if message := response['output'].get('message'): # pragma: no branch for item in message['content']: if reasoning_content := item.get('reasoningContent'): if redacted_content := reasoning_content.get('redactedContent'): items.append( ThinkingPart( id='redacted_content', content='', signature=redacted_content.decode('utf-8'), provider_name=self.system, ) ) elif reasoning_text := reasoning_content.get('reasoningText'): # pragma: no branch signature = reasoning_text.get('signature') items.append( ThinkingPart( content=reasoning_text['text'], signature=signature, provider_name=self.system if signature else None, ) ) if text := item.get('text'): items.append(TextPart(content=text)) elif tool_use := item.get('toolUse'): items.append( ToolCallPart( tool_name=tool_use['name'], args=tool_use['input'], tool_call_id=tool_use['toolUseId'], ), ) u = usage.RequestUsage( input_tokens=response['usage']['inputTokens'], output_tokens=response['usage']['outputTokens'], ) response_id = response.get('ResponseMetadata', {}).get('RequestId', None) raw_finish_reason = response['stopReason'] provider_details = {'finish_reason': raw_finish_reason} finish_reason = _FINISH_REASON_MAP.get(raw_finish_reason) return ModelResponse( parts=items, usage=u, model_name=self.model_name, provider_response_id=response_id, provider_name=self._provider.name, finish_reason=finish_reason, provider_details=provider_details, ) @overload async def _messages_create( self, messages: list[ModelMessage], stream: Literal[True], model_settings: BedrockModelSettings | None, model_request_parameters: ModelRequestParameters, ) -> ConverseStreamResponseTypeDef: pass @overload async def _messages_create( self, messages: list[ModelMessage], stream: Literal[False], model_settings: BedrockModelSettings | None, model_request_parameters: ModelRequestParameters, ) -> ConverseResponseTypeDef: pass async def _messages_create( self, messages: list[ModelMessage], stream: bool, model_settings: BedrockModelSettings | None, model_request_parameters: ModelRequestParameters, ) -> ConverseResponseTypeDef | ConverseStreamResponseTypeDef: system_prompt, bedrock_messages = await self._map_messages(messages) inference_config = self._map_inference_config(model_settings) params: ConverseRequestTypeDef = { 'modelId': self.model_name, 'messages': bedrock_messages, 'system': system_prompt, 'inferenceConfig': inference_config, } tool_config = self._map_tool_config(model_request_parameters) if tool_config: params['toolConfig'] = tool_config if model_request_parameters.builtin_tools: raise UserError('Bedrock does not support built-in tools') # Bedrock supports a set of specific extra parameters if model_settings: if guardrail_config := model_settings.get('bedrock_guardrail_config', None): params['guardrailConfig'] = guardrail_config if performance_configuration := model_settings.get('bedrock_performance_configuration', None): params['performanceConfig'] = performance_configuration if request_metadata := model_settings.get('bedrock_request_metadata', None): params['requestMetadata'] = request_metadata if additional_model_response_fields_paths := model_settings.get( 'bedrock_additional_model_response_fields_paths', None ): params['additionalModelResponseFieldPaths'] = additional_model_response_fields_paths if additional_model_requests_fields := model_settings.get('bedrock_additional_model_requests_fields', None): params['additionalModelRequestFields'] = additional_model_requests_fields if prompt_variables := model_settings.get('bedrock_prompt_variables', None): params['promptVariables'] = prompt_variables if stream: model_response = await anyio.to_thread.run_sync(functools.partial(self.client.converse_stream, **params)) else: model_response = await anyio.to_thread.run_sync(functools.partial(self.client.converse, **params)) return model_response @staticmethod def _map_inference_config( model_settings: ModelSettings | None, ) -> InferenceConfigurationTypeDef: model_settings = model_settings or {} inference_config: InferenceConfigurationTypeDef = {} if max_tokens := model_settings.get('max_tokens'): inference_config['maxTokens'] = max_tokens if (temperature := model_settings.get('temperature')) is not None: inference_config['temperature'] = temperature if top_p := model_settings.get('top_p'): inference_config['topP'] = top_p if stop_sequences := model_settings.get('stop_sequences'): inference_config['stopSequences'] = stop_sequences return inference_config def _map_tool_config(self, model_request_parameters: ModelRequestParameters) -> ToolConfigurationTypeDef | None: tools = self._get_tools(model_request_parameters) if not tools: return None tool_choice: ToolChoiceTypeDef if not model_request_parameters.allow_text_output: tool_choice = {'any': {}} else: tool_choice = {'auto': {}} tool_config: ToolConfigurationTypeDef = {'tools': tools} if tool_choice and BedrockModelProfile.from_profile(self.profile).bedrock_supports_tool_choice: tool_config['toolChoice'] = tool_choice return tool_config async def _map_messages( # noqa: C901 self, messages: list[ModelMessage] ) -> tuple[list[SystemContentBlockTypeDef], list[MessageUnionTypeDef]]: """Maps a `pydantic_ai.Message` to the Bedrock `MessageUnionTypeDef`. Groups consecutive ToolReturnPart objects into a single user message as required by Bedrock Claude/Nova models. """ profile = BedrockModelProfile.from_profile(self.profile) system_prompt: list[SystemContentBlockTypeDef] = [] bedrock_messages: list[MessageUnionTypeDef] = [] document_count: Iterator[int] = count(1) for message in messages: if isinstance(message, ModelRequest): for part in message.parts: if isinstance(part, SystemPromptPart) and part.content: system_prompt.append({'text': part.content}) elif isinstance(part, UserPromptPart): bedrock_messages.extend(await self._map_user_prompt(part, document_count)) elif isinstance(part, ToolReturnPart): assert part.tool_call_id is not None bedrock_messages.append( { 'role': 'user', 'content': [ { 'toolResult': { 'toolUseId': part.tool_call_id, 'content': [ {'text': part.model_response_str()} if profile.bedrock_tool_result_format == 'text' else {'json': part.model_response_object()} ], 'status': 'success', } } ], } ) elif isinstance(part, RetryPromptPart): # TODO(Marcelo): We need to add a test here. if part.tool_name is None: # pragma: no cover bedrock_messages.append({'role': 'user', 'content': [{'text': part.model_response()}]}) else: assert part.tool_call_id is not None bedrock_messages.append( { 'role': 'user', 'content': [ { 'toolResult': { 'toolUseId': part.tool_call_id, 'content': [{'text': part.model_response()}], 'status': 'error', } } ], } ) elif isinstance(message, ModelResponse): content: list[ContentBlockOutputTypeDef] = [] for item in message.parts: if isinstance(item, TextPart): content.append({'text': item.content}) elif isinstance(item, ThinkingPart): if ( item.provider_name == self.system and item.signature and BedrockModelProfile.from_profile(self.profile).bedrock_send_back_thinking_parts ): if item.id == 'redacted_content': reasoning_content: ReasoningContentBlockOutputTypeDef = { 'redactedContent': item.signature.encode('utf-8'), } else: reasoning_content: ReasoningContentBlockOutputTypeDef = { 'reasoningText': { 'text': item.content, 'signature': item.signature, } } content.append({'reasoningContent': reasoning_content}) else: start_tag, end_tag = self.profile.thinking_tags content.append({'text': '\n'.join([start_tag, item.content, end_tag])}) elif isinstance(item, BuiltinToolCallPart | BuiltinToolReturnPart): pass else: assert isinstance(item, ToolCallPart) content.append(self._map_tool_call(item)) bedrock_messages.append({'role': 'assistant', 'content': content}) else: assert_never(message) # Merge together sequential user messages. processed_messages: list[MessageUnionTypeDef] = [] last_message: dict[str, Any] | None = None for current_message in bedrock_messages: if ( last_message is not None and current_message['role'] == last_message['role'] and current_message['role'] == 'user' ): # Add the new user content onto the existing user message. last_content = list(last_message['content']) last_content.extend(current_message['content']) last_message['content'] = last_content continue # Add the entire message to the list of messages. processed_messages.append(current_message) last_message = cast(dict[str, Any], current_message) if instructions := self._get_instructions(messages): system_prompt.insert(0, {'text': instructions}) return system_prompt, processed_messages @staticmethod async def _map_user_prompt(part: UserPromptPart, document_count: Iterator[int]) -> list[MessageUnionTypeDef]: content: list[ContentBlockUnionTypeDef] = [] if isinstance(part.content, str): content.append({'text': part.content}) else: for item in part.content: if isinstance(item, str): content.append({'text': item}) elif isinstance(item, BinaryContent): format = item.format if item.is_document: name = f'Document {next(document_count)}' assert format in ('pdf', 'txt', 'csv', 'doc', 'docx', 'xls', 'xlsx', 'html', 'md') content.append({'document': {'name': name, 'format': format, 'source': {'bytes': item.data}}}) elif item.is_image: assert format in ('jpeg', 'png', 'gif', 'webp') content.append({'image': {'format': format, 'source': {'bytes': item.data}}}) elif item.is_video: assert format in ('mkv', 'mov', 'mp4', 'webm', 'flv', 'mpeg', 'mpg', 'wmv', 'three_gp') content.append({'video': {'format': format, 'source': {'bytes': item.data}}}) else: raise NotImplementedError('Binary content is not supported yet.') elif isinstance(item, ImageUrl | DocumentUrl | VideoUrl): downloaded_item = await download_item(item, data_format='bytes', type_format='extension') format = downloaded_item['data_type'] if item.kind == 'image-url': format = item.media_type.split('/')[1] assert format in ('jpeg', 'png', 'gif', 'webp'), f'Unsupported image format: {format}' image: ImageBlockTypeDef = {'format': format, 'source': {'bytes': downloaded_item['data']}} content.append({'image': image}) elif item.kind == 'document-url': name = f'Document {next(document_count)}' document: DocumentBlockTypeDef = { 'name': name, 'format': item.format, 'source': {'bytes': downloaded_item['data']}, } content.append({'document': document}) elif item.kind == 'video-url': # pragma: no branch format = item.media_type.split('/')[1] assert format in ( 'mkv', 'mov', 'mp4', 'webm', 'flv', 'mpeg', 'mpg', 'wmv', 'three_gp', ), f'Unsupported video format: {format}' video: VideoBlockTypeDef = {'format': format, 'source': {'bytes': downloaded_item['data']}} content.append({'video': video}) elif isinstance(item, AudioUrl): # pragma: no cover raise NotImplementedError('Audio is not supported yet.') else: assert_never(item) return [{'role': 'user', 'content': content}] @staticmethod def _map_tool_call(t: ToolCallPart) -> ContentBlockOutputTypeDef: return { 'toolUse': {'toolUseId': _utils.guard_tool_call_id(t=t), 'name': t.tool_name, 'input': t.args_as_dict()} } @dataclass class BedrockStreamedResponse(StreamedResponse): """Implementation of `StreamedResponse` for Bedrock models.""" _model_name: BedrockModelName _event_stream: EventStream[ConverseStreamOutputTypeDef] _provider_name: str _timestamp: datetime = field(default_factory=_utils.now_utc) _provider_response_id: str | None = None async def _get_event_iterator(self) -> AsyncIterator[ModelResponseStreamEvent]: # noqa: C901 """Return an async iterator of [`ModelResponseStreamEvent`][pydantic_ai.messages.ModelResponseStreamEvent]s. This method should be implemented by subclasses to translate the vendor-specific stream of events into pydantic_ai-format events. """ if self._provider_response_id is not None: # pragma: no cover self.provider_response_id = self._provider_response_id chunk: ConverseStreamOutputTypeDef tool_id: str | None = None async for chunk in _AsyncIteratorWrapper(self._event_stream): match chunk: case {'messageStart': _}: continue case {'messageStop': message_stop}: raw_finish_reason = message_stop['stopReason'] self.provider_details = {'finish_reason': raw_finish_reason} self.finish_reason = _FINISH_REASON_MAP.get(raw_finish_reason) case {'metadata': metadata}: if 'usage' in metadata: # pragma: no branch self._usage += self._map_usage(metadata) case {'contentBlockStart': content_block_start}: index = content_block_start['contentBlockIndex'] start = content_block_start['start'] if 'toolUse' in start: # pragma: no branch tool_use_start = start['toolUse'] tool_id = tool_use_start['toolUseId'] tool_name = tool_use_start['name'] maybe_event = self._parts_manager.handle_tool_call_delta( vendor_part_id=index, tool_name=tool_name, args=None, tool_call_id=tool_id, ) if maybe_event: # pragma: no branch yield maybe_event case {'contentBlockDelta': content_block_delta}: index = content_block_delta['contentBlockIndex'] delta = content_block_delta['delta'] if 'reasoningContent' in delta: if redacted_content := delta['reasoningContent'].get('redactedContent'): yield self._parts_manager.handle_thinking_delta( vendor_part_id=index, id='redacted_content', signature=redacted_content.decode('utf-8'), provider_name=self.provider_name, ) else: signature = delta['reasoningContent'].get('signature') yield self._parts_manager.handle_thinking_delta( vendor_part_id=index, content=delta['reasoningContent'].get('text'), signature=signature, provider_name=self.provider_name if signature else None, ) if text := delta.get('text'): maybe_event = self._parts_manager.handle_text_delta(vendor_part_id=index, content=text) if maybe_event is not None: # pragma: no branch yield maybe_event if 'toolUse' in delta: tool_use = delta['toolUse'] maybe_event = self._parts_manager.handle_tool_call_delta( vendor_part_id=index, tool_name=tool_use.get('name'), args=tool_use.get('input'), tool_call_id=tool_id, ) if maybe_event: # pragma: no branch yield maybe_event case _: pass # pyright wants match statements to be exhaustive @property def model_name(self) -> str: """Get the model name of the response.""" return self._model_name @property def provider_name(self) -> str: """Get the provider name.""" return self._provider_name @property def timestamp(self) -> datetime: return self._timestamp def _map_usage(self, metadata: ConverseStreamMetadataEventTypeDef) -> usage.RequestUsage: return usage.RequestUsage( input_tokens=metadata['usage']['inputTokens'], output_tokens=metadata['usage']['outputTokens'], ) class _AsyncIteratorWrapper(Generic[T]): """Wrap a synchronous iterator in an async iterator.""" def __init__(self, sync_iterator: Iterable[T]): self.sync_iterator = iter(sync_iterator) def __aiter__(self): return self async def __anext__(self) -> T: try: return await anyio.to_thread.run_sync(next, self.sync_iterator) except RuntimeError as e: if type(e.__cause__) is StopIteration: raise StopAsyncIteration else: raise e # pragma: lax no cover