langchain_community.callbacks.streamlit.streamlit_callback_handler.StreamlitCallbackHandler¶

class langchain_community.callbacks.streamlit.streamlit_callback_handler.StreamlitCallbackHandler(parent_container: DeltaGenerator, *, max_thought_containers: int = 4, expand_new_thoughts: bool = True, collapse_completed_thoughts: bool = True, thought_labeler: Optional[LLMThoughtLabeler] = None)[source]¶

Callback handler that writes to a Streamlit app.

Create a StreamlitCallbackHandler instance.

Parameters

  • parent_container (DeltaGenerator) – The st.container that will contain all the Streamlit elements that the Handler creates.

  • max_thought_containers (int) – The max number of completed LLM thought containers to show at once. When this threshold is reached, a new thought will cause the oldest thoughts to be collapsed into a “History” expander. Defaults to 4.

  • expand_new_thoughts (bool) – Each LLM “thought” gets its own st.expander. This param controls whether that expander is expanded by default. Defaults to True.

  • collapse_completed_thoughts (bool) – If True, LLM thought expanders will be collapsed when completed. Defaults to True.

  • thought_labeler (Optional[LLMThoughtLabeler]) – An optional custom LLMThoughtLabeler instance. If unspecified, the handler will use the default thought labeling logic. Defaults to None.

Attributes

ignore_agent

Whether to ignore agent callbacks.

ignore_chain

Whether to ignore chain callbacks.

ignore_chat_model

Whether to ignore chat model callbacks.

ignore_custom_event

Ignore custom event.

ignore_llm

Whether to ignore LLM callbacks.

ignore_retriever

Whether to ignore retriever callbacks.

ignore_retry

Whether to ignore retry callbacks.

raise_error

Whether to raise an error if an exception occurs.

run_inline

Whether to run the callback inline.

Methods

__init__(parent_container, *[, ...])

Create a StreamlitCallbackHandler instance.

on_agent_action(action[, color])

Run on agent action.

on_agent_finish(finish[, color])

Run on the agent end.

on_chain_end(outputs, **kwargs)

Run when chain ends running.

on_chain_error(error, **kwargs)

Run when chain errors.

on_chain_start(serialized, inputs, **kwargs)

Run when a chain starts running.

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

Run when a chat model starts running.

on_custom_event(name, data, *, run_id[, ...])

Override to define a handler for a custom event.

on_llm_end(response, **kwargs)

Run when LLM ends running.

on_llm_error(error, **kwargs)

Run when LLM errors.

on_llm_new_token(token, **kwargs)

Run on new LLM token.

on_llm_start(serialized, prompts, **kwargs)

Run when LLM starts running.

on_retriever_end(documents, *, run_id[, ...])

Run when Retriever ends running.

on_retriever_error(error, *, run_id[, ...])

Run when Retriever errors.

on_retriever_start(serialized, query, *, run_id)

Run when the Retriever starts running.

on_retry(retry_state, *, run_id[, parent_run_id])

Run on a retry event.

on_text(text[, color, end])

Run on an arbitrary text.

on_tool_end(output[, color, ...])

Run when the tool ends running.

on_tool_error(error, **kwargs)

Run when tool errors.

on_tool_start(serialized, input_str, **kwargs)

Run when the tool starts running.
__init__(parent_container: DeltaGenerator, *, max_thought_containers: int = 4, expand_new_thoughts: bool = True, collapse_completed_thoughts: bool = True, thought_labeler: Optional[LLMThoughtLabeler] = None)[source]¶

Create a StreamlitCallbackHandler instance.

Parameters

  • parent_container (DeltaGenerator) – The st.container that will contain all the Streamlit elements that the Handler creates.

  • max_thought_containers (int) – The max number of completed LLM thought containers to show at once. When this threshold is reached, a new thought will cause the oldest thoughts to be collapsed into a “History” expander. Defaults to 4.

  • expand_new_thoughts (bool) – Each LLM “thought” gets its own st.expander. This param controls whether that expander is expanded by default. Defaults to True.

  • collapse_completed_thoughts (bool) – If True, LLM thought expanders will be collapsed when completed. Defaults to True.

  • thought_labeler (Optional[LLMThoughtLabeler]) – An optional custom LLMThoughtLabeler instance. If unspecified, the handler will use the default thought labeling logic. Defaults to None.

on_agent_action(action: AgentAction, color: Optional[str] = None, **kwargs: Any) → Any[source]¶

Run on agent action.

Parameters

  • action (AgentAction) – The agent action.

  • 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.

  • kwargs (Any) – Additional keyword arguments.

  • color (Optional[str]) –

Return type

Any

on_agent_finish(finish: AgentFinish, color: Optional[str] = None, **kwargs: Any) → None[source]¶

Run on the agent end.

Parameters

  • finish (AgentFinish) – The agent finish.

  • 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.

  • kwargs (Any) – Additional keyword arguments.

  • color (Optional[str]) –

Return type

None

on_chain_end(outputs: Dict[str, Any], **kwargs: Any) → None[source]¶

Run when chain ends running.

Parameters

  • outputs (Dict[str, Any]) – The outputs of the chain.

  • 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.

  • kwargs (Any) – Additional keyword arguments.

Return type

None

on_chain_error(error: BaseException, **kwargs: Any) → None[source]¶

Run when chain errors.

Parameters

  • error (BaseException) – The error that occurred.

  • 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.

  • kwargs (Any) – Additional keyword arguments.

Return type

None

on_chain_start(serialized: Dict[str, Any], inputs: Dict[str, Any], **kwargs: Any) → None[source]¶

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

None

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_custom_event(name: str, data: Any, *, run_id: UUID, tags: Optional[List[str]] = None, metadata: Optional[Dict[str, Any]] = None, **kwargs: Any) → Any¶

Override to define a handler for a custom event.

Parameters

  • name (str) – The name of the custom event.

  • data (Any) – The data for the custom event. Format will match the format specified by the user.

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

  • tags (Optional[List[str]]) – The tags associated with the custom event (includes inherited tags).

  • metadata (Optional[Dict[str, Any]]) – The metadata associated with the custom event (includes inherited metadata).

  • kwargs (Any) –

Return type

Any

New in version 0.2.15.

on_llm_end(response: LLMResult, **kwargs: Any) → None[source]¶

Run when LLM ends running.

Parameters

  • response (LLMResult) – The response which was generated.

  • 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.

  • kwargs (Any) – Additional keyword arguments.

Return type

None

on_llm_error(error: BaseException, **kwargs: Any) → None[source]¶

Run when LLM errors.

Parameters

  • error (BaseException) – The error that occurred.

  • 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.

  • kwargs (Any) – Additional keyword arguments.

Return type

None

on_llm_new_token(token: str, **kwargs: Any) → None[source]¶

Run on new LLM token. Only available when streaming is enabled.

Parameters

  • token (str) – The new token.

  • chunk (GenerationChunk | ChatGenerationChunk) – The new generated chunk, containing content and other information.

  • 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.

  • kwargs (Any) – Additional keyword arguments.

Return type

None

on_llm_start(serialized: Dict[str, Any], prompts: List[str], **kwargs: Any) → None[source]¶

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

None

on_retriever_end(documents: Sequence[Document], *, run_id: UUID, parent_run_id: Optional[UUID] = None, **kwargs: Any) → Any¶

Run when Retriever ends running.

Parameters

  • documents (Sequence[Document]) – The documents retrieved.

  • 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.

  • kwargs (Any) – Additional keyword arguments.

Return type

Any

on_retriever_error(error: BaseException, *, run_id: UUID, parent_run_id: Optional[UUID] = None, **kwargs: Any) → Any¶

Run when Retriever errors.

Parameters

  • error (BaseException) – The error that occurred.

  • 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.

  • 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_retry(retry_state: RetryCallState, *, run_id: UUID, parent_run_id: Optional[UUID] = None, **kwargs: Any) → Any¶

Run on a retry event.

Parameters

  • retry_state (RetryCallState) – The retry state.

  • 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.

  • kwargs (Any) – Additional keyword arguments.

Return type

Any

on_text(text: str, color: Optional[str] = None, end: str = '', **kwargs: Any) → None[source]¶

Run on an arbitrary text.

Parameters

  • text (str) – The text.

  • 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.

  • kwargs (Any) – Additional keyword arguments.

  • color (Optional[str]) –

  • end (str) –

Return type

None

on_tool_end(output: Any, color: Optional[str] = None, observation_prefix: Optional[str] = None, llm_prefix: Optional[str] = None, **kwargs: Any) → None[source]¶

Run when the tool ends running.

Parameters

  • output (Any) – The output of the tool.

  • 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.

  • kwargs (Any) – Additional keyword arguments.

  • color (Optional[str]) –

  • observation_prefix (Optional[str]) –

  • llm_prefix (Optional[str]) –

Return type

None

on_tool_error(error: BaseException, **kwargs: Any) → None[source]¶

Run when tool errors.

Parameters

  • error (BaseException) – The error that occurred.

  • 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.

  • kwargs (Any) – Additional keyword arguments.

Return type

None

on_tool_start(serialized: Dict[str, Any], input_str: str, **kwargs: Any) → None[source]¶

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

None

Examples using StreamlitCallbackHandler¶