UsageMetadataCallbackHandler#

class langchain_core.callbacks.usage.UsageMetadataCallbackHandler[source]#

Callback Handler that tracks AIMessage.usage_metadata.

Example

from langchain.chat_models import init_chat_model
from langchain_core.callbacks import UsageMetadataCallbackHandler

llm_1 = init_chat_model(model="openai:gpt-4o-mini")
llm_2 = init_chat_model(model="anthropic:claude-3-5-haiku-latest")

callback = UsageMetadataCallbackHandler()
result_1 = llm_1.invoke("Hello", config={"callbacks": [callback]})
result_2 = llm_2.invoke("Hello", config={"callbacks": [callback]})
callback.usage_metadata

{'gpt-4o-mini-2024-07-18': {'input_tokens': 8,
  'output_tokens': 10,
  'total_tokens': 18,
  'input_token_details': {'audio': 0, 'cache_read': 0},
  'output_token_details': {'audio': 0, 'reasoning': 0}},
 'claude-3-5-haiku-20241022': {'input_tokens': 8,
  'output_tokens': 21,
  'total_tokens': 29,
  'input_token_details': {'cache_read': 0, 'cache_creation': 0}}}

Added in version 0.3.49.

Initialize the UsageMetadataCallbackHandler.

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__`()	Initialize the UsageMetadataCallbackHandler.
`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[, parent_run_id])	Run when chain ends running.
`on_chain_error`(error, *, run_id[, parent_run_id])	Run when chain errors.
`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_custom_event`(name, data, *, run_id[, ...])	Override to define a handler for a custom event.
`on_llm_end`(response, **kwargs)	Collect token usage.
`on_llm_error`(error, *, run_id[, parent_run_id])	Run when LLM errors.
`on_llm_new_token`(token, *[, chunk, ...])	Run on new LLM token.
`on_llm_start`(serialized, prompts, *, run_id)	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, *, run_id[, parent_run_id])	Run on an arbitrary text.
`on_tool_end`(output, *, run_id[, parent_run_id])	Run when the tool ends running.
`on_tool_error`(error, *, run_id[, parent_run_id])	Run when tool errors.
`on_tool_start`(serialized, input_str, *, run_id)	Run when the tool starts running.

__init__() → None[source]#

Initialize the UsageMetadataCallbackHandler.

Return type:: None

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,

parent_run_id: UUID | None = None,

**kwargs: Any,

) → Any#

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:

Any

on_chain_error(

error: BaseException,

*,

run_id: UUID,

parent_run_id: UUID | None = None,

**kwargs: Any,

) → Any#

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:

Any

on_chain_start(

serialized: dict[str, Any],

inputs: dict[str, Any],

*,

run_id: UUID,

parent_run_id: UUID | None = None,

tags: list[str] | None = None,

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

tags: list[str] | None = None,

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

**kwargs: Any,

) → None[source]#

Collect token usage.

Parameters:

response (LLMResult)
kwargs (Any)

Return type:

None

on_llm_error(

error: BaseException,

*,

run_id: UUID,

parent_run_id: UUID | None = None,

**kwargs: Any,

) → Any#

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:

Any

on_llm_new_token(

token: str,

*,

chunk: GenerationChunk | ChatGenerationChunk | None = None,

run_id: UUID,

parent_run_id: UUID | None = None,

**kwargs: Any,

) → Any#

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:

Any

on_llm_start(

serialized: dict[str, Any],

prompts: list[str],

*,

run_id: UUID,

parent_run_id: UUID | None = None,

tags: list[str] | None = None,

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

documents: Sequence[Document],

*,

run_id: UUID,

parent_run_id: UUID | None = 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: UUID | None = 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: UUID | None = None,

tags: list[str] | None = None,

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

*,

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,

parent_run_id: UUID | None = None,

**kwargs: Any,

) → Any#

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.

Return type:

Any

on_tool_error(

error: BaseException,

*,

run_id: UUID,

parent_run_id: UUID | None = None,

**kwargs: Any,

) → Any#

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:

Any

on_tool_start(

serialized: dict[str, Any],

input_str: str,

*,

run_id: UUID,

parent_run_id: UUID | None = None,

tags: list[str] | None = None,

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

inputs: dict[str, Any] | None = 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