LangChainTracer

class langchain_core.tracers.langchain.LangChainTracer(

example_id: UUID | str | None = None,

project_name: str | None = None,

client: Client | None = None,

tags: list[str] | None = None,

**kwargs: Any,

)

Implementation of the SharedTracer that POSTS to the LangChain endpoint.

Initialize the LangChain tracer.

Parameters:

• example_id (Optional[Union[UUID, str]]) – The example ID.

• project_name (Optional[str]) – The project name. Defaults to the tracer project.

• client (Optional[Client]) – The client. Defaults to the global client.

• tags (Optional[list[str]]) – The tags. Defaults to an empty list.

• kwargs (Any) – Additional keyword arguments.

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.
log_missing_parent
raise_error	Whether to raise an error if an exception occurs.
run_inline	Whether to run the callback inline.

Methods

__init__([example_id, project_name, client, ...])	Initialize the LangChain tracer.
get_run_url()	Get the LangSmith root run URL.
on_agent_action(action, *, run_id[, ...])	Run on agent action.
on_agent_finish(finish, *, run_id[, ...])	Run on the agent end.
on_chain_end(outputs, *, run_id[, inputs])	End a trace for a chain run.
on_chain_error(error, *[, inputs])	Handle an error for a chain run.
on_chain_start(serialized, inputs, *, run_id)	Start a trace for a chain run.
on_chat_model_start(serialized, messages, *, ...)	Start a trace for an LLM run.
on_custom_event(name, data, *, run_id[, ...])	Override to define a handler for a custom event.
on_llm_end(response, *, run_id, **kwargs)	End a trace for an LLM run.
on_llm_error(error, *, run_id, **kwargs)	Handle an error for an LLM run.
on_llm_new_token(token, *[, chunk, ...])	Run on new LLM token.
on_llm_start(serialized, prompts, *, run_id)	Start a trace for an LLM run.
on_retriever_end(documents, *, run_id, **kwargs)	Run when the Retriever ends running.
on_retriever_error(error, *, run_id, **kwargs)	Run when Retriever errors.
on_retriever_start(serialized, query, *, run_id)	Run when the Retriever starts running.
on_retry(retry_state, *, run_id, **kwargs)	Run on retry.
on_text(text, *, run_id[, parent_run_id])	Run on an arbitrary text.
on_tool_end(output, *, run_id, **kwargs)	End a trace for a tool run.
on_tool_error(error, *, run_id, **kwargs)	Handle an error for a tool run.
on_tool_start(serialized, input_str, *, run_id)	Start a trace for a tool run.
wait_for_futures()	Wait for the given futures to complete.

__init__(

example_id: UUID | str | None = None,

project_name: str | None = None,

client: Client | None = None,

tags: list[str] | None = None,

**kwargs: Any,

) → None

Initialize the LangChain tracer.

Parameters:

• example_id (UUID | str | None) – The example ID.

• project_name (str | None) – The project name. Defaults to the tracer project.

• client (Client | None) – The client. Defaults to the global client.

• tags (list[str] | None) – The tags. Defaults to an empty list.

• kwargs (Any) – Additional keyword arguments.

Return type:

None

get_run_url() → str

Get the LangSmith root run URL.

Returns:

The LangSmith root run URL.

Return type:

str

Raises:

• ValueError – If no traced run is found.

• ValueError – If the run URL cannot be found.

on_agent_action(

action: AgentAction,

*,

run_id: UUID,

parent_run_id: UUID | None = None,

**kwargs: Any,

) → Any

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.

Return type:

Any

on_agent_finish(

finish: AgentFinish,

*,

run_id: UUID,

parent_run_id: UUID | None = None,

**kwargs: Any,

) → Any

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.

Return type:

Any

on_chain_end(

outputs: dict[str, Any],

*,

run_id: UUID,

inputs: dict[str, Any] | None = None,

**kwargs: Any,

) → Run

End a trace for a chain run.

Parameters:

• outputs (dict[str, Any]) – The outputs for the chain.

• run_id (UUID) – The run ID.

• inputs (Optional[dict[str, Any]]) – The inputs for the chain. Defaults to None.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

on_chain_error(

error: BaseException,

*,

inputs: dict[str, Any] | None = None,

run_id: UUID,

**kwargs: Any,

) → Run

Handle an error for a chain run.

Parameters:

• error (BaseException) – The error.

• inputs (Optional[dict[str, Any]]) – The inputs for the chain. Defaults to None.

• run_id (UUID) – The run ID.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

on_chain_start(

serialized: dict[str, Any],

inputs: dict[str, Any],

*,

run_id: UUID,

tags: list[str] | None = None,

parent_run_id: UUID | None = None,

metadata: dict[str, Any] | None = None,

run_type: str | None = None,

name: str | None = None,

**kwargs: Any,

) → Run

Start a trace for a chain run.

Parameters:

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

• inputs (dict[str, Any]) – The inputs for the chain.

• run_id (UUID) – The run ID.

• tags (Optional[list[str]]) – The tags for the run. Defaults to None.

• parent_run_id (Optional[UUID]) – The parent run ID. Defaults to None.

• metadata (Optional[dict[str, Any]]) – The metadata for the run. Defaults to None.

• run_type (Optional[str]) – The type of the run. Defaults to None.

• name (Optional[str]) – The name of the run.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

on_chat_model_start(

serialized: dict[str, Any],

messages: list[list[BaseMessage]],

*,

run_id: UUID,

tags: list[str] | None = None,

parent_run_id: UUID | None = None,

metadata: dict[str, Any] | None = None,

name: str | None = None,

**kwargs: Any,

) → Run

Start a trace for an LLM run.

Parameters:

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

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

• run_id (UUID) – The run ID.

• tags (Optional[list[str]]) – The tags. Defaults to None.

• parent_run_id (Optional[UUID]) – The parent run ID. Defaults to None.

• metadata (Optional[dict[str, Any]]) – The metadata. Defaults to None.

• name (Optional[str]) – The name. Defaults to None.

• kwargs (Any) – Additional keyword arguments.

Returns:

The run.

Return type:

Run

on_custom_event(

name: str,

data: Any,

*,

run_id: UUID,

tags: list[str] | None = None,

metadata: dict[str, Any] | None = 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

Added in version 0.2.15.

on_llm_end(

response: LLMResult,

*,

run_id: UUID,

**kwargs: Any,

) → Run

End a trace for an LLM run.

Parameters:

• response (LLMResult) – The response.

• run_id (UUID) – The run ID.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

on_llm_error(

error: BaseException,

*,

run_id: UUID,

**kwargs: Any,

) → Run

Handle an error for an LLM run.

Parameters:

• error (BaseException) – The error.

• run_id (UUID) – The run ID.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

on_llm_new_token(

token: str,

*,

chunk: GenerationChunk | ChatGenerationChunk | None = None,

run_id: UUID,

parent_run_id: UUID | None = None,

**kwargs: Any,

) → Run

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

Parameters:

• token (str) – The token.

• chunk (Optional[Union[GenerationChunk, ChatGenerationChunk]]) – The chunk. Defaults to None.

• run_id (UUID) – The run ID.

• parent_run_id (Optional[UUID]) – The parent run ID. Defaults to None.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

on_llm_start(

serialized: dict[str, Any],

prompts: list[str],

*,

run_id: UUID,

tags: list[str] | None = None,

parent_run_id: UUID | None = None,

metadata: dict[str, Any] | None = None,

name: str | None = None,

**kwargs: Any,

) → Run

Start a trace for an LLM run.

Parameters:

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

• prompts (list[str]) – The prompts to start the LLM with.

• run_id (UUID) – The run ID.

• tags (Optional[list[str]]) – The tags for the run. Defaults to None.

• parent_run_id (Optional[UUID]) – The parent run ID. Defaults to None.

• metadata (Optional[dict[str, Any]]) – The metadata for the run. Defaults to None.

• name (Optional[str]) – The name of the run.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

on_retriever_end(

documents: Sequence[Document],

*,

run_id: UUID,

**kwargs: Any,

) → Run

Run when the Retriever ends running.

Parameters:

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

• run_id (UUID) – The run ID.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

on_retriever_error(

error: BaseException,

*,

run_id: UUID,

**kwargs: Any,

) → Run

Run when Retriever errors.

Parameters:

• error (BaseException) – The error.

• run_id (UUID) – The run ID.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

on_retriever_start(

serialized: dict[str, Any],

query: str,

*,

run_id: UUID,

parent_run_id: UUID | None = None,

tags: list[str] | None = None,

metadata: dict[str, Any] | None = None,

name: str | None = None,

**kwargs: Any,

) → Run

Run when the Retriever starts running.

Parameters:

• serialized (dict[str, Any]) – The serialized retriever.

• query (str) – The query.

• run_id (UUID) – The run ID.

• parent_run_id (Optional[UUID]) – The parent run ID. Defaults to None.

• tags (Optional[list[str]]) – The tags for the run. Defaults to None.

• metadata (Optional[dict[str, Any]]) – The metadata for the run. Defaults to None.

• name (Optional[str]) – The name of the run.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

on_retry(

retry_state: RetryCallState,

*,

run_id: UUID,

**kwargs: Any,

) → Run

Run on retry.

Parameters:

• retry_state (RetryCallState) – The retry state.

• run_id (UUID) – The run ID.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

on_text(

text: str,

*,

run_id: UUID,

parent_run_id: UUID | None = None,

**kwargs: Any,

) → Any

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.

Return type:

Any

on_tool_end(

output: Any,

*,

run_id: UUID,

**kwargs: Any,

) → Run

End a trace for a tool run.

Parameters:

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

• run_id (UUID) – The run ID.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

on_tool_error(

error: BaseException,

*,

run_id: UUID,

**kwargs: Any,

) → Run

Handle an error for a tool run.

Parameters:

• error (BaseException) – The error.

• run_id (UUID) – The run ID.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

on_tool_start(

serialized: dict[str, Any],

input_str: str,

*,

run_id: UUID,

tags: list[str] | None = None,

parent_run_id: UUID | None = None,

metadata: dict[str, Any] | None = None,

name: str | None = None,

inputs: dict[str, Any] | None = None,

**kwargs: Any,

) → Run

Start a trace for a tool run.

Parameters:

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

• input_str (str) – The input string.

• run_id (UUID) – The run ID.

• tags (Optional[list[str]]) – The tags for the run. Defaults to None.

• parent_run_id (Optional[UUID]) – The parent run ID. Defaults to None.

• metadata (Optional[dict[str, Any]]) – The metadata for the run. Defaults to None.

• name (Optional[str]) – The name of the run.

• inputs (Optional[dict[str, Any]]) – The inputs for the tool.

• kwargs (Any) – Additional arguments.

Returns:

The run.

Return type:

Run

wait_for_futures() → None

Wait for the given futures to complete.

Return type:

None