langchain_core.callbacks.base.BaseCallbackManager¶

class langchain_core.callbacks.base.BaseCallbackManager(handlers: List[BaseCallbackHandler], inheritable_handlers: Optional[List[BaseCallbackHandler]] = None, parent_run_id: Optional[UUID] = None, *, tags: Optional[List[str]] = None, inheritable_tags: Optional[List[str]] = None, metadata: Optional[Dict[str, Any]] = None, inheritable_metadata: Optional[Dict[str, Any]] = None)[source]¶

Base callback manager for LangChain.

Initialize callback manager.

Parameters

  • handlers (List[BaseCallbackHandler]) – The handlers.

  • inheritable_handlers (Optional[List[BaseCallbackHandler]]) – The inheritable handlers. Default is None.

  • parent_run_id (Optional[UUID]) – The parent run ID. Default is None.

  • tags (Optional[List[str]]) – The tags. Default is None.

  • inheritable_tags (Optional[List[str]]) – The inheritable tags. Default is None.

  • metadata (Optional[Dict[str, Any]]) – The metadata. Default is None.

  • inheritable_metadata (Optional[Dict[str, Any]]) –

Attributes

is_async

Whether the callback manager is async.

Methods

__init__(handlers[, inheritable_handlers, ...])

Initialize callback manager.

add_handler(handler[, inherit])

Add a handler to the callback manager.

add_metadata(metadata[, inherit])

Add metadata to the callback manager.

add_tags(tags[, inherit])

Add tags to the callback manager.

copy()

Copy the callback manager.

on_chain_start(serialized, inputs, *, run_id)

Run when a chain starts running.

on_chat_model_start(serialized, messages, *, ...)

Run when a chat model starts running.

on_llm_start(serialized, prompts, *, run_id)

Run when LLM starts running.

on_retriever_start(serialized, query, *, run_id)

Run when the Retriever starts running.

on_tool_start(serialized, input_str, *, run_id)

Run when the tool starts running.

remove_handler(handler)

Remove a handler from the callback manager.

remove_metadata(keys)

Remove metadata from the callback manager.

remove_tags(tags)

Remove tags from the callback manager.

set_handler(handler[, inherit])

Set handler as the only handler on the callback manager.

set_handlers(handlers[, inherit])

Set handlers as the only handlers on the callback manager.
__init__(handlers: List[BaseCallbackHandler], inheritable_handlers: Optional[List[BaseCallbackHandler]] = None, parent_run_id: Optional[UUID] = None, *, tags: Optional[List[str]] = None, inheritable_tags: Optional[List[str]] = None, metadata: Optional[Dict[str, Any]] = None, inheritable_metadata: Optional[Dict[str, Any]] = None) → None[source]¶

Initialize callback manager.

Parameters

  • handlers (List[BaseCallbackHandler]) – The handlers.

  • inheritable_handlers (Optional[List[BaseCallbackHandler]]) – The inheritable handlers. Default is None.

  • parent_run_id (Optional[UUID]) – The parent run ID. Default is None.

  • tags (Optional[List[str]]) – The tags. Default is None.

  • inheritable_tags (Optional[List[str]]) – The inheritable tags. Default is None.

  • metadata (Optional[Dict[str, Any]]) – The metadata. Default is None.

  • inheritable_metadata (Optional[Dict[str, Any]]) –

Return type

None

add_handler(handler: BaseCallbackHandler, inherit: bool = True) → None[source]¶

Add a handler to the callback manager.

Parameters

  • handler (BaseCallbackHandler) – The handler to add.

  • inherit (bool) – Whether to inherit the handler. Default is True.

Return type

None

add_metadata(metadata: Dict[str, Any], inherit: bool = True) → None[source]¶

Add metadata to the callback manager.

Parameters

  • metadata (Dict[str, Any]) – The metadata to add.

  • inherit (bool) – Whether to inherit the metadata. Default is True.

Return type

None

add_tags(tags: List[str], inherit: bool = True) → None[source]¶

Add tags to the callback manager.

Parameters

  • tags (List[str]) – The tags to add.

  • inherit (bool) – Whether to inherit the tags. Default is True.

Return type

None

copy() → T[source]¶

Copy the callback manager.

Parameters

self (T) –

Return type

T

on_chain_start(serialized: Dict[str, Any], inputs: Dict[str, Any], *, run_id: UUID, parent_run_id: Optional[UUID] = None, tags: Optional[List[str]] = None, metadata: Optional[Dict[str, Any]] = None, **kwargs: Any) → Any¶

Run when a chain starts running.

Parameters

  • serialized (Dict[str, Any]) – The serialized chain.

  • inputs (Dict[str, Any]) – The inputs.

  • run_id (UUID) – The run ID. This is the ID of the current run.

  • parent_run_id (UUID) – The parent run ID. This is the ID of the parent run.

  • tags (Optional[List[str]]) – The tags.

  • metadata (Optional[Dict[str, Any]]) – The metadata.

  • kwargs (Any) – Additional keyword arguments.

Return type

Any

on_chat_model_start(serialized: Dict[str, Any], messages: List[List[BaseMessage]], *, run_id: UUID, parent_run_id: Optional[UUID] = None, tags: Optional[List[str]] = None, metadata: Optional[Dict[str, Any]] = None, **kwargs: Any) → Any¶

Run when a chat model starts running.

ATTENTION: This method is called for chat models. If you’re implementing

a handler for a non-chat model, you should use on_llm_start instead.

Parameters

  • serialized (Dict[str, Any]) – The serialized chat model.

  • messages (List[List[BaseMessage]]) – The messages.

  • run_id (UUID) – The run ID. This is the ID of the current run.

  • parent_run_id (UUID) – The parent run ID. This is the ID of the parent run.

  • tags (Optional[List[str]]) – The tags.

  • metadata (Optional[Dict[str, Any]]) – The metadata.

  • kwargs (Any) – Additional keyword arguments.

Return type

Any

on_llm_start(serialized: Dict[str, Any], prompts: List[str], *, run_id: UUID, parent_run_id: Optional[UUID] = None, tags: Optional[List[str]] = None, metadata: Optional[Dict[str, Any]] = None, **kwargs: Any) → Any¶

Run when LLM starts running.

ATTENTION: This method is called for non-chat models (regular LLMs). If

you’re implementing a handler for a chat model, you should use on_chat_model_start instead.

Parameters

  • serialized (Dict[str, Any]) – The serialized LLM.

  • prompts (List[str]) – The prompts.

  • run_id (UUID) – The run ID. This is the ID of the current run.

  • parent_run_id (UUID) – The parent run ID. This is the ID of the parent run.

  • tags (Optional[List[str]]) – The tags.

  • metadata (Optional[Dict[str, Any]]) – The metadata.

  • kwargs (Any) – Additional keyword arguments.

Return type

Any

on_retriever_start(serialized: Dict[str, Any], query: str, *, run_id: UUID, parent_run_id: Optional[UUID] = None, tags: Optional[List[str]] = None, metadata: Optional[Dict[str, Any]] = None, **kwargs: Any) → Any¶

Run when the Retriever starts running.

Parameters

  • serialized (Dict[str, Any]) – The serialized Retriever.

  • query (str) – The query.

  • run_id (UUID) – The run ID. This is the ID of the current run.

  • parent_run_id (UUID) – The parent run ID. This is the ID of the parent run.

  • tags (Optional[List[str]]) – The tags.

  • metadata (Optional[Dict[str, Any]]) – The metadata.

  • kwargs (Any) – Additional keyword arguments.

Return type

Any

on_tool_start(serialized: Dict[str, Any], input_str: str, *, run_id: UUID, parent_run_id: Optional[UUID] = None, tags: Optional[List[str]] = None, metadata: Optional[Dict[str, Any]] = None, inputs: Optional[Dict[str, Any]] = None, **kwargs: Any) → Any¶

Run when the tool starts running.

Parameters

  • serialized (Dict[str, Any]) – The serialized tool.

  • input_str (str) – The input string.

  • run_id (UUID) – The run ID. This is the ID of the current run.

  • parent_run_id (UUID) – The parent run ID. This is the ID of the parent run.

  • tags (Optional[List[str]]) – The tags.

  • metadata (Optional[Dict[str, Any]]) – The metadata.

  • inputs (Optional[Dict[str, Any]]) – The inputs.

  • kwargs (Any) – Additional keyword arguments.

Return type

Any

remove_handler(handler: BaseCallbackHandler) → None[source]¶

Remove a handler from the callback manager.

Parameters

handler (BaseCallbackHandler) – The handler to remove.

Return type

None

remove_metadata(keys: List[str]) → None[source]¶

Remove metadata from the callback manager.

Parameters

keys (List[str]) – The keys to remove.

Return type

None

remove_tags(tags: List[str]) → None[source]¶

Remove tags from the callback manager.

Parameters

tags (List[str]) – The tags to remove.

Return type

None

set_handler(handler: BaseCallbackHandler, inherit: bool = True) → None[source]¶

Set handler as the only handler on the callback manager.

Parameters

  • handler (BaseCallbackHandler) – The handler to set.

  • inherit (bool) – Whether to inherit the handler. Default is True.

Return type

None

set_handlers(handlers: List[BaseCallbackHandler], inherit: bool = True) → None[source]¶

Set handlers as the only handlers on the callback manager.

Parameters

  • handlers (List[BaseCallbackHandler]) – The handlers to set.

  • inherit (bool) – Whether to inherit the handlers. Default is True.

Return type

None