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JavaScript@langchain/coretracersconsoleConsoleCallbackHandler
Class●Since v1.0

ConsoleCallbackHandler

A tracer that logs all events to the console. It extends from the BaseTracer class and overrides its methods to provide custom logging functionality.

Copy
class ConsoleCallbackHandler

Bases

BaseTracer

Used in Docs

  • Zep cloud integration

Example

Copy
const llm = new ChatAnthropic({
  temperature: 0,
  tags: ["example", "callbacks", "constructor"],
  callbacks: [new ConsoleCallbackHandler()],
});

Constructors

constructor
constructor

Properties

property
awaitHandlers: boolean
property
ignoreAgent: boolean
property
ignoreChain: boolean
property
ignoreCustomEvent: boolean
property
ignoreLLM: boolean
property
ignoreRetriever: boolean
property
lc_kwargs: SerializedFields
property
lc_serializable: boolean
property
name: "console_callback_handler"
property
raiseError: boolean
property
runMap: Map<string, Run>
property
runTreeMap: Map<string, RunTree>
property
usesRunTreeMap: boolean
property
lc_aliases: __type | undefined
property
lc_attributes: __type | undefined
property
lc_id: string[]
property
lc_namespace: ["langchain_core", "callbacks", string]

A path to the module that contains the class, eg. ["langchain", "llms"] Usually should be the same as the entrypoint the class is exported from.

property
lc_secrets: __type | undefined
property
lc_serializable_keys: string[] | undefined

Methods

method
_addChildRun
method
_addRunToRunMap→ __type
method
_createRunForChainStart→ __type

Create and add a run to the run map for chain start events. This must sometimes be done synchronously to avoid race conditions when callbacks are backgrounded, so we expose it as a separate method here.

method
_createRunForChatModelStart→ __type

Create and add a run to the run map for chat model start events. This must sometimes be done synchronously to avoid race conditions when callbacks are backgrounded, so we expose it as a separate method here.

method
_createRunForLLMStart→ __type

Create and add a run to the run map for LLM start events. This must sometimes be done synchronously to avoid race conditions when callbacks are backgrounded, so we expose it as a separate method here.

method
_createRunForRetrieverStart→ __type

Create and add a run to the run map for retriever start events. This must sometimes be done synchronously to avoid race conditions when callbacks are backgrounded, so we expose it as a separate method here.

method
_createRunForToolStart→ __type

Create and add a run to the run map for tool start events. This must sometimes be done synchronously to avoid race conditions when callbacks are backgrounded, so we expose it as a separate method here.

method
_endTrace
method
_getExecutionOrder
method
copy→ BaseCallbackHandler
method
getBreadcrumbs→ string

Method used to get a string representation of the run's lineage, which is used in logging.

method
getParents→ Run[]

Method used to get all the parent runs of a given run.

method
getRunById
method
handleAgentAction→ void | Promise<void>

Called when an agent is about to execute an action, with the action and the run ID.

method
handleAgentEnd→ void | Promise<void>

Called when an agent finishes execution, before it exits. with the final output and the run ID.

method
handleChainEnd→ any

Called at the end of a Chain run, with the outputs and the run ID.

method
handleChainError→ any

Called if a Chain run encounters an error

method
handleChainStart→ any

Called at the start of a Chain run, with the chain name and inputs and the run ID.

method
handleChatModelStart→ any

Called at the start of a Chat Model run, with the prompt(s) and the run ID.

method
handleCustomEvent→ any
method
handleLLMEnd→ any

Called at the end of an LLM/ChatModel run, with the output and the run ID.

method
handleLLMError→ any

Called if an LLM/ChatModel run encounters an error

method
handleLLMNewToken→ any

Called when an LLM/ChatModel in streaming mode produces a new token

method
handleLLMStart→ any

Called at the start of an LLM or Chat Model run, with the prompt(s) and the run ID.

method
handleRetrieverEnd→ any
method
handleRetrieverError→ any
method
handleRetrieverStart→ any
method
handleText→ void | Promise<void>
method
handleToolEnd→ any

Called at the end of a Tool run, with the tool output and the run ID.

method
handleToolError→ any

Called if a Tool run encounters an error

method
handleToolStart→ any

Called at the start of a Tool run, with the tool name and input and the run ID.

method
onAgentAction→ void | Promise<void>
method
onAgentEnd→ void | Promise<void>
method
onChainEnd→ void | Promise<void>
method
onChainError→ void | Promise<void>
method
onChainStart→ void | Promise<void>
method
onLLMEnd→ void | Promise<void>
method
onLLMError→ void | Promise<void>
method
onLLMNewToken→ void | Promise<void>
method
onLLMStart→ void | Promise<void>
method
onRetrieverEnd→ void | Promise<void>
method
onRetrieverError→ void | Promise<void>
method
onRetrieverStart→ void | Promise<void>
method
onRunCreate→ void | Promise<void>
method
onRunUpdate→ void | Promise<void>
method
onText→ void | Promise<void>
method
onToolEnd→ void | Promise<void>
method
onToolError→ void | Promise<void>
method
onToolStart→ void | Promise<void>
method
persistRun→ Promise<void>
method
stringifyError
method
toJSON→ Serialized
method
toJSONNotImplemented→ SerializedNotImplemented
method
fromMethods→ Handler
method
lc_name→ string

The name of the serializable. Override to provide an alias or to preserve the serialized module name in minified environments.

Implemented as a static method to support loading logic.

Inherited fromBaseTracer

Properties

PawaitHandlers: booleanPignoreAgent: booleanPignoreChain: booleanPignoreCustomEvent: booleanPignoreLLM: booleanPignoreRetriever: booleanPlc_kwargs: SerializedFieldsPlc_serializable: booleanPname: stringPraiseError: booleanPrunMapPrunTreeMapPusesRunTreeMap: booleanPlc_aliases: __type | undefinedPlc_attributes: __type | undefinedPlc_id: string[]Plc_namespace: ["langchain_core", "callbacks", string]
—

A path to the module that contains the class, eg. ["langchain", "llms"]

Plc_secrets: __type | undefinedPlc_serializable_keys: string[] | undefined

Methods

M_addChildRunM_addRunToRunMap→ __typeM_createRunForChainStart→ __type
—

Create and add a run to the run map for chain start events.

M_createRunForChatModelStart→ __type
—

Create and add a run to the run map for chat model start events.

M_createRunForLLMStart→ __type
—

Create and add a run to the run map for LLM start events.

M_createRunForRetrieverStart→ __type
—

Create and add a run to the run map for retriever start events.

M_createRunForToolStart→ __type
—

Create and add a run to the run map for tool start events.

M_endTraceM_getExecutionOrderMcopy→ BaseCallbackHandlerMgetRunByIdMhandleAgentAction→ void | Promise<void>
—

Called when an agent is about to execute an action,

MhandleAgentEnd→ void | Promise<void>
—

Called when an agent finishes execution, before it exits.

MhandleChainEnd→ any
—

Called at the end of a Chain run, with the outputs and the run ID.

MhandleChainError→ any
—

Called if a Chain run encounters an error

MhandleChainStart→ any
—

Called at the start of a Chain run, with the chain name and inputs

MhandleChatModelStart→ any
—

Called at the start of a Chat Model run, with the prompt(s)

MhandleCustomEvent→ anyMhandleLLMEnd→ any
—

Called at the end of an LLM/ChatModel run, with the output and the run ID.

MhandleLLMError→ any
—

Called if an LLM/ChatModel run encounters an error

MhandleLLMNewToken→ any
—

Called when an LLM/ChatModel in streaming mode produces a new token

MhandleLLMStart→ any
—

Called at the start of an LLM or Chat Model run, with the prompt(s)

MhandleRetrieverEnd→ anyMhandleRetrieverError→ anyMhandleRetrieverStart→ anyMhandleText→ void | Promise<void>MhandleToolEnd→ any
—

Called at the end of a Tool run, with the tool output and the run ID.

MhandleToolError→ any
—

Called if a Tool run encounters an error

MhandleToolStart→ any
—

Called at the start of a Tool run, with the tool name and input

MonAgentAction→ void | Promise<void>MonAgentEnd→ void | Promise<void>MonChainEnd→ void | Promise<void>MonChainError→ void | Promise<void>MonChainStart→ void | Promise<void>MonLLMEnd→ void | Promise<void>MonLLMError→ void | Promise<void>MonLLMNewToken→ void | Promise<void>MonLLMStart→ void | Promise<void>MonRetrieverEnd→ void | Promise<void>MonRetrieverError→ void | Promise<void>MonRetrieverStart→ void | Promise<void>MonRunCreate→ void | Promise<void>MonRunUpdate→ void | Promise<void>MonText→ void | Promise<void>MonToolEnd→ void | Promise<void>MonToolError→ void | Promise<void>MonToolStart→ void | Promise<void>MpersistRun→ Promise<void>MstringifyErrorMtoJSON→ SerializedMtoJSONNotImplemented→ SerializedNotImplementedMfromMethods→ HandlerMlc_name→ string
—

The name of the serializable. Override to provide an alias or

Inherited fromBaseCallbackHandler

Properties

PawaitHandlers: booleanPignoreAgent: booleanPignoreChain: booleanPignoreCustomEvent: booleanPignoreLLM: booleanPignoreRetriever: booleanPlc_kwargs: SerializedFieldsPlc_serializable: booleanPname: stringPraiseError: booleanPlc_aliases: __type | undefinedPlc_attributes: __type | undefinedPlc_id: string[]Plc_namespace: ["langchain_core", "callbacks", string]
—

A path to the module that contains the class, eg. ["langchain", "llms"]

Plc_secrets: __type | undefinedPlc_serializable_keys: string[] | undefined

Methods

Mcopy→ BaseCallbackHandlerMhandleAgentAction→ void | Promise<void>
—

Called when an agent is about to execute an action,

MhandleAgentEnd→ void | Promise<void>
—

Called when an agent finishes execution, before it exits.

MhandleChainEnd→ any
—

Called at the end of a Chain run, with the outputs and the run ID.

MhandleChainError→ any
—

Called if a Chain run encounters an error

MhandleChainStart→ any
—

Called at the start of a Chain run, with the chain name and inputs

MhandleChatModelStart→ any
—

Called at the start of a Chat Model run, with the prompt(s)

MhandleCustomEvent→ anyMhandleLLMEnd→ any
—

Called at the end of an LLM/ChatModel run, with the output and the run ID.

MhandleLLMError→ any
—

Called if an LLM/ChatModel run encounters an error

MhandleLLMNewToken→ any
—

Called when an LLM/ChatModel in streaming mode produces a new token

MhandleLLMStart→ any
—

Called at the start of an LLM or Chat Model run, with the prompt(s)

MhandleRetrieverEnd→ anyMhandleRetrieverError→ anyMhandleRetrieverStart→ anyMhandleText→ void | Promise<void>MhandleToolEnd→ any
—

Called at the end of a Tool run, with the tool output and the run ID.

MhandleToolError→ any
—

Called if a Tool run encounters an error

MhandleToolStart→ any
—

Called at the start of a Tool run, with the tool name and input

MtoJSON→ SerializedMtoJSONNotImplemented→ SerializedNotImplementedMfromMethods→ HandlerMlc_name→ string
—

The name of the serializable. Override to provide an alias or

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