LangChain Reference home pageLangChain ReferenceLangChain Reference
  • GitHub
  • Main Docs
Deep Agents
LangChain
LangGraph
Integrations
LangSmith
  • Overview
    • Overview
    • Caches
    • Callbacks
    • Documents
    • Document loaders
    • Embeddings
    • Exceptions
    • Language models
    • Serialization
    • Output parsers
    • Prompts
    • Rate limiters
    • Retrievers
    • Runnables
    • Utilities
    • Vector stores
    MCP Adapters
    Standard Tests
    Text Splitters
    ⌘I

    LangChain Assistant

    Ask a question to get started

    Enter to send•Shift+Enter new line

    Menu

    OverviewCachesCallbacksDocumentsDocument loadersEmbeddingsExceptionsLanguage modelsSerializationOutput parsersPromptsRate limitersRetrieversRunnablesUtilitiesVector stores
    MCP Adapters
    Standard Tests
    Text Splitters
    Language
    Theme
    Pythonlangchain-coretracerslog_streamLogStreamCallbackHandler
    Class●Since v0.1

    LogStreamCallbackHandler

    Tracer that streams run logs to a stream.

    Copy
    LogStreamCallbackHandler(
      self,
      *,
      auto_close: bool = True,
      include_names: Sequence[str] | None = None,
      include_types: Sequence[str] | None = None,
      include_tags: Sequence[str] | None = None,
      exclude_names: Sequence[str] | None = None,
      exclude_types: Sequence[str] | None = None,
      exclude_tags: Sequence[str] | None = None,
      _schema_format: Literal['original', 'streaming_events'] = 'streaming_events'
    )

    Bases

    BaseTracer_StreamingCallbackHandler

    Parameters

    NameTypeDescription
    auto_closebool
    Default:True

    Whether to close the stream when the root run finishes.

    include_namesSequence[str] | None
    Default:None

    Only include runs from Runnable objects with matching names.

    include_typesSequence[str] | None
    Default:None

    Only include runs from Runnable objects with matching types.

    include_tagsSequence[str] | None
    Default:None

    Only include runs from Runnable objects with matching tags.

    exclude_namesSequence[str] | None
    Default:None

    Exclude runs from Runnable objects with matching names.

    exclude_typesSequence[str] | None
    Default:None

    Exclude runs from Runnable objects with matching types.

    exclude_tagsSequence[str] | None
    Default:None

    Exclude runs from Runnable objects with matching tags.

    _schema_formatLiteral['original', 'streaming_events']
    Default:'streaming_events'

    Primarily changes how the inputs and outputs are handled.

    For internal use only. This API will change.

    • 'original' is the format used by all current tracers. This format is slightly inconsistent with respect to inputs and outputs.
    • 'streaming_events' is used for supporting streaming events, for internal usage. It will likely change in the future, or be deprecated entirely in favor of a dedicated async tracer for streaming events.

    Constructors

    constructor
    __init__
    NameType
    auto_closebool
    include_namesSequence[str] | None
    include_typesSequence[str] | None
    include_tagsSequence[str] | None
    exclude_namesSequence[str] | None
    exclude_typesSequence[str] | None
    exclude_tagsSequence[str] | None
    _schema_formatLiteral['original', 'streaming_events']

    Attributes

    attribute
    auto_close: auto_close
    attribute
    include_names: include_names
    attribute
    include_types: include_types
    attribute
    include_tags: include_tags
    attribute
    exclude_names: exclude_names
    attribute
    exclude_types: exclude_types
    attribute
    exclude_tags: exclude_tags
    attribute
    lock
    attribute
    send_stream
    attribute
    receive_stream
    attribute
    root_id: UUID | None

    Methods

    method
    send

    Send a patch to the stream, return False if the stream is closed.

    method
    tap_output_aiter

    Tap an output async iterator to stream its values to the log.

    method
    tap_output_iter

    Tap an output iterator to stream its values to the log.

    method
    include_run

    Check if a Run should be included in the log.

    Inherited fromBaseTracer

    Methods

    Mon_chat_model_start
    —

    Start a trace for a chat model run.

    Mon_llm_start
    —

    Start a trace for a (non-chat model) LLM run.

    Mon_llm_new_token
    —

    Run on new output token.

    Mon_retry
    —

    Run on retry.

    Mon_llm_end
    —

    End a trace for a model run.

    Mon_llm_error
    —

    Handle an error for an LLM run.

    Mon_chain_start
    —

    Start a trace for a chain run.

    Mon_chain_end
    —

    End a trace for a chain run.

    Mon_chain_error
    —

    Handle an error for a chain run.

    Mon_tool_start
    —

    Start a trace for a tool run.

    Mon_tool_end
    —

    End a trace for a tool run.

    Mon_tool_error
    —

    Run when tool errors.

    Mon_retriever_start
    —

    Run when Retriever starts running.

    Mon_retriever_error
    —

    Run when Retriever errors.

    Mon_retriever_end
    —

    Run when Retriever ends running.

    Inherited fromBaseCallbackHandler

    Attributes

    Araise_error: bool
    —

    Whether to raise an error if an exception occurs.

    Arun_inline: boolAignore_llm: bool
    —

    Whether to ignore LLM callbacks.

    Aignore_retry: bool
    —

    Whether to ignore retry callbacks.

    Aignore_chain: bool
    —

    Whether to ignore chain callbacks.

    Aignore_agent: bool
    —

    Whether to ignore agent callbacks.

    Aignore_retriever: bool
    —

    Whether to ignore retriever callbacks.

    Aignore_chat_model: bool
    —

    Whether to ignore chat model callbacks.

    Aignore_custom_event: bool
    —

    Ignore custom event.

    Inherited fromLLMManagerMixin

    Methods

    Mon_llm_new_token
    —

    Run on new output token.

    Mon_llm_end
    —

    End a trace for a model run.

    Mon_llm_error
    —

    Handle an error for an LLM run.

    Inherited fromChainManagerMixin

    Methods

    Mon_chain_end
    —

    End a trace for a chain run.

    Mon_chain_error
    —

    Handle an error for a chain run.

    Mon_agent_action
    —

    Run on agent action.

    Mon_agent_finish
    —

    Run on the agent end.

    Inherited fromToolManagerMixin

    Methods

    Mon_tool_end
    —

    End a trace for a tool run.

    Mon_tool_error
    —

    Run when tool errors.

    Inherited fromRetrieverManagerMixin

    Methods

    Mon_retriever_error
    —

    Run when Retriever errors.

    Mon_retriever_end
    —

    Run when Retriever ends running.

    Inherited fromCallbackManagerMixin

    Methods

    Mon_llm_start
    —

    Start a trace for a (non-chat model) LLM run.

    Mon_chat_model_start
    —

    Start a trace for a chat model run.

    Mon_retriever_start
    —

    Run when Retriever starts running.

    Mon_chain_start
    —

    Start a trace for a chain run.

    Mon_tool_start
    —

    Start a trace for a tool run.

    Inherited fromRunManagerMixin

    Methods

    Mon_text
    —

    Run on an arbitrary text.

    Mon_retry
    —

    Run on retry.

    Mon_custom_event
    —

    Generate a custom astream event.

    View source on GitHub