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mirascope.core.bedrock.stream

The BedrockStream class for convenience around streaming LLM calls.

Usage Documentation

Streams

BedrockStream 

BedrockStream(*args: Any, **kwargs: Any)

Bases: BaseStream[BedrockCallResponse, BedrockCallResponseChunk, UserMessageTypeDef, AssistantMessageTypeDef, ToolUseBlockMessageTypeDef, InternalBedrockMessageParam, BedrockTool, ToolTypeDef, BedrockDynamicConfig, BedrockCallParams, StopReasonType]

A class for convenience around streaming Bedrock LLM calls.

Example:

from mirascope.core import prompt_template
from mirascope.core.bedrock import bedrock_call


@bedrock_call("gpt-4o-mini", stream=True)
@prompt_template("Recommend a {genre} book")
def recommend_book(genre: str):
    ...


stream = recommend_book("fantasy")  # returns `BedrockStream` instance
for chunk, _ in stream:
    print(chunk.content, end="", flush=True)
Source code in mirascope/core/bedrock/stream.py 
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def __init__(self, *args: Any, **kwargs: Any) -> None:  # noqa: ANN401
    super().__init__(*args, **kwargs)
    self._metadata: (
        ConverseStreamMetadataEventTypeDef
        | AsyncConverseStreamMetadataEventTypeDef
        | None
    ) = None
    self._response_metadata: (
        ResponseMetadataTypeDef | AsyncResponseMetadataTypeDef
    ) = _DEFAULT_RESPONSE_METADATA

cost property 

cost: float | None

Returns the cost of the call.

construct_call_response 

construct_call_response() -> BedrockCallResponse

Constructs the call response from a consumed BedrockStream.

Raises:

Type Description
ValueError

if the stream has not yet been consumed.
Source code in mirascope/core/bedrock/stream.py 
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def construct_call_response(self) -> BedrockCallResponse:
    """Constructs the call response from a consumed BedrockStream.

    Raises:
        ValueError: if the stream has not yet been consumed.
    """
    if not hasattr(self, "message_param"):
        raise ValueError(
            "No stream response, check if the stream has been consumed."
        )
    response = ConverseResponseTypeDef(
        output={"message": cast(MessageOutputTypeDef, self.message_param)},
        stopReason=self.finish_reasons[0] if self.finish_reasons else "end_turn",
        usage=self.metadata.get("usage", {}),
        metrics=self.metadata.get("metrics", {}),
        additionalModelResponseFields={},
        trace=self.metadata.get("trace", {}),
        ResponseMetadata=self._response_metadata,
    )
    return BedrockCallResponse(
        metadata=self.metadata,
        response=response,
        tool_types=self.tool_types,
        prompt_template=self.prompt_template,
        fn_args=self.fn_args if self.fn_args else {},
        dynamic_config=self.dynamic_config,
        messages=self.messages,
        call_params=self.call_params,
        call_kwargs=self.call_kwargs,
        user_message_param=self.user_message_param,
        start_time=self.start_time,
        end_time=self.end_time,
    )