Class 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.

Example


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

Hierarchy (view full)

BaseTracer
- ConsoleCallbackHandler

Constructors

constructor

new ConsoleCallbackHandler(_fields?): ConsoleCallbackHandler
Parameters
- Optional_fields: BaseCallbackHandlerInput
Returns ConsoleCallbackHandler
Inherited from BaseTracer.constructor
- Defined in langchain-core/src/tracers/base.ts:70

Properties

awaitHandlers

awaitHandlers: boolean = ...

ignoreAgent

ignoreAgent: boolean = false

ignoreChain

ignoreChain: boolean = false

ignoreCustomEvent

ignoreCustomEvent: boolean = false

ignoreLLM

ignoreLLM: boolean = false

ignoreRetriever

ignoreRetriever: boolean = false

name

name: "console_callback_handler" = ...

raiseError

raiseError: boolean = false

`Protected`runMap

runMap: Map<string, Run> = ...

Methods

copy

copy(): this
Returns this
Inherited from BaseTracer.copy
- Defined in langchain-core/src/tracers/base.ts:74

getBreadcrumbs

getBreadcrumbs(run): string
Method used to get a string representation of the run's lineage, which is used in logging.
Parameters
- run: Run
  The run whose lineage is to be retrieved.
Returns string
A string representation of the run's lineage.
- Defined in langchain-core/src/tracers/console.ts:96

getParents

getParents(run): Run[]
Method used to get all the parent runs of a given run.
Parameters
- run: Run
  The run whose parents are to be retrieved.
Returns Run[]
An array of parent runs.
- Defined in langchain-core/src/tracers/console.ts:75

handleAgentAction

handleAgentAction(action, runId): Promise<void>
Called when an agent is about to execute an action, with the action and the run ID.
Parameters
- action: AgentAction
- runId: string
Returns Promise<void>
Inherited from BaseTracer.handleAgentAction
- Defined in langchain-core/src/tracers/base.ts:547

handleAgentEnd

handleAgentEnd(action, runId): Promise<void>
Called when an agent finishes execution, before it exits. with the final output and the run ID.
Parameters
- action: AgentFinish
- runId: string
Returns Promise<void>
Inherited from BaseTracer.handleAgentEnd
- Defined in langchain-core/src/tracers/base.ts:563

handleChainEnd

handleChainEnd(outputs, runId, _parentRunId?, _tags?, kwargs?): Promise<Run>
Called at the end of a Chain run, with the outputs and the run ID.
Parameters
- outputs: ChainValues
- runId: string
- Optional_parentRunId: string
- Optional_tags: string[]
- Optionalkwargs: {
  inputs?: Record<string, unknown>;
  }
  - Optionalinputs?: Record<string, unknown>
Returns Promise<Run>
Inherited from BaseTracer.handleChainEnd
- Defined in langchain-core/src/tracers/base.ts:400

handleChainError

handleChainError(error, runId, _parentRunId?, _tags?, kwargs?): Promise<Run>
Called if a Chain run encounters an error
Parameters
- error: unknown
- runId: string
- Optional_parentRunId: string
- Optional_tags: string[]
- Optionalkwargs: {
  inputs?: Record<string, unknown>;
  }
  - Optionalinputs?: Record<string, unknown>
Returns Promise<Run>
Inherited from BaseTracer.handleChainError
- Defined in langchain-core/src/tracers/base.ts:425

handleChainStart

handleChainStart(chain, inputs, runId, parentRunId?, tags?, metadata?, runType?, name?): Promise<Run>
Called at the start of a Chain run, with the chain name and inputs and the run ID.
Parameters
- chain: Serialized
- inputs: ChainValues
- runId: string
- OptionalparentRunId: string
- Optionaltags: string[]
- Optionalmetadata: KVMap
- OptionalrunType: string
- Optionalname: string
Returns Promise<Run>
Inherited from BaseTracer.handleChainStart
- Defined in langchain-core/src/tracers/base.ts:373

handleChatModelStart

handleChatModelStart(llm, messages, runId, parentRunId?, extraParams?, tags?, metadata?, name?): Promise<Run>
Called at the start of a Chat Model run, with the prompt(s) and the run ID.
Parameters
- llm: Serialized
- messages: BaseMessage[][]
- runId: string
- OptionalparentRunId: string
- OptionalextraParams: KVMap
- Optionaltags: string[]
- Optionalmetadata: KVMap
- Optionalname: string
Returns Promise<Run>
Inherited from BaseTracer.handleChatModelStart
- Defined in langchain-core/src/tracers/base.ts:274

`Optional`handleCustomEvent

handleCustomEvent(eventName, data, runId, tags?, metadata?): any
Parameters
- eventName: string
- data: any
- runId: string
- Optionaltags: string[]
- Optionalmetadata: Record<string, any>
Returns any
Inherited from BaseTracer.handleCustomEvent
- Defined in langchain-core/src/callbacks/base.ts:265

handleLLMEnd

handleLLMEnd(output, runId): Promise<Run>
Called at the end of an LLM/ChatModel run, with the output and the run ID.
Parameters
- output: LLMResult
- runId: string
Returns Promise<Run>
Inherited from BaseTracer.handleLLMEnd
- Defined in langchain-core/src/tracers/base.ts:301

handleLLMError

handleLLMError(error, runId): Promise<Run>
Called if an LLM/ChatModel run encounters an error
Parameters
- error: unknown
- runId: string
Returns Promise<Run>
Inherited from BaseTracer.handleLLMError
- Defined in langchain-core/src/tracers/base.ts:317

handleLLMNewToken

handleLLMNewToken(token, idx, runId, _parentRunId?, _tags?, fields?): Promise<Run>
Called when an LLM/ChatModel in streaming mode produces a new token
Parameters
- token: string
- idx: NewTokenIndices
  idx.prompt is the index of the prompt that produced the token (if there are multiple prompts) idx.completion is the index of the completion that produced the token (if multiple completions per prompt are requested)
- runId: string
- Optional_parentRunId: string
- Optional_tags: string[]
- Optionalfields: HandleLLMNewTokenCallbackFields
Returns Promise<Run>
Inherited from BaseTracer.handleLLMNewToken
- Defined in langchain-core/src/tracers/base.ts:688

handleLLMStart

handleLLMStart(llm, prompts, runId, parentRunId?, extraParams?, tags?, metadata?, name?): Promise<Run>
Called at the start of an LLM or Chat Model run, with the prompt(s) and the run ID.
Parameters
- llm: Serialized
- prompts: string[]
- runId: string
- OptionalparentRunId: string
- OptionalextraParams: KVMap
- Optionaltags: string[]
- Optionalmetadata: KVMap
- Optionalname: string
Returns Promise<Run>
Inherited from BaseTracer.handleLLMStart
- Defined in langchain-core/src/tracers/base.ts:204

handleRetrieverEnd

handleRetrieverEnd(documents, runId): Promise<Run>
Parameters
- documents: Document<Record<string, unknown>>[]
- runId: string
Returns Promise<Run>
Inherited from BaseTracer.handleRetrieverEnd
- Defined in langchain-core/src/tracers/base.ts:640

handleRetrieverError

handleRetrieverError(error, runId): Promise<Run>
Parameters
- error: unknown
- runId: string
Returns Promise<Run>
Inherited from BaseTracer.handleRetrieverError
- Defined in langchain-core/src/tracers/base.ts:659

handleRetrieverStart

handleRetrieverStart(retriever, query, runId, parentRunId?, tags?, metadata?, name?): Promise<Run>
Parameters
- retriever: Serialized
- query: string
- runId: string
- OptionalparentRunId: string
- Optionaltags: string[]
- Optionalmetadata: KVMap
- Optionalname: string
Returns Promise<Run>
Inherited from BaseTracer.handleRetrieverStart
- Defined in langchain-core/src/tracers/base.ts:615

handleText

handleText(text, runId): Promise<void>
Parameters
- text: string
- runId: string
Returns Promise<void>
Inherited from BaseTracer.handleText
- Defined in langchain-core/src/tracers/base.ts:675

handleToolEnd

handleToolEnd(output, runId): Promise<Run>
Called at the end of a Tool run, with the tool output and the run ID.
Parameters
- output: any
- runId: string
Returns Promise<Run>
Inherited from BaseTracer.handleToolEnd
- Defined in langchain-core/src/tracers/base.ts:515

handleToolError

handleToolError(error, runId): Promise<Run>
Called if a Tool run encounters an error
Parameters
- error: unknown
- runId: string
Returns Promise<Run>
Inherited from BaseTracer.handleToolError
- Defined in langchain-core/src/tracers/base.ts:531

handleToolStart

handleToolStart(tool, input, runId, parentRunId?, tags?, metadata?, name?): Promise<Run>
Called at the start of a Tool run, with the tool name and input and the run ID.
Parameters
- tool: Serialized
- input: string
- runId: string
- OptionalparentRunId: string
- Optionaltags: string[]
- Optionalmetadata: KVMap
- Optionalname: string
Returns Promise<Run>
Inherited from BaseTracer.handleToolStart
- Defined in langchain-core/src/tracers/base.ts:489

onAgentAction

onAgentAction(run): void
Method used to log the action selected by the agent.
Parameters
- run: Run
  The run in which the agent action occurred.
Returns void
void
Overrides BaseTracer.onAgentAction
- Defined in langchain-core/src/tracers/console.ts:322

`Optional`onAgentEnd

onAgentEnd(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
Inherited from BaseTracer.onAgentEnd
- Defined in langchain-core/src/tracers/base.ts:737

onChainEnd

onChainEnd(run): void
Method used to log the end of a chain run.
Parameters
- run: Run
  The chain run that has ended.
Returns void
void
Overrides BaseTracer.onChainEnd
- Defined in langchain-core/src/tracers/console.ts:132

onChainError

onChainError(run): void
Method used to log any errors of a chain run.
Parameters
- run: Run
  The chain run that has errored.
Returns void
void
Overrides BaseTracer.onChainError
- Defined in langchain-core/src/tracers/console.ts:149

onChainStart

onChainStart(run): void
Method used to log the start of a chain run.
Parameters
- run: Run
  The chain run that has started.
Returns void
void
Overrides BaseTracer.onChainStart
- Defined in langchain-core/src/tracers/console.ts:114

onLLMEnd

onLLMEnd(run): void
Method used to log the end of an LLM run.
Parameters
- run: Run
  The LLM run that has ended.
Returns void
void
Overrides BaseTracer.onLLMEnd
- Defined in langchain-core/src/tracers/console.ts:188

onLLMError

onLLMError(run): void
Method used to log any errors of an LLM run.
Parameters
- run: Run
  The LLM run that has errored.
Returns void
void
Overrides BaseTracer.onLLMError
- Defined in langchain-core/src/tracers/console.ts:205

`Optional`onLLMNewToken

onLLMNewToken(run, token, kwargs?): void | Promise<void>
Parameters
- run: Run
- token: string
- Optionalkwargs: {
  chunk: any;
  }
  - chunk: any
Returns void | Promise<void>
Inherited from BaseTracer.onLLMNewToken
- Defined in langchain-core/src/tracers/base.ts:747

onLLMStart

onLLMStart(run): void
Method used to log the start of an LLM run.
Parameters
- run: Run
  The LLM run that has started.
Returns void
void
Overrides BaseTracer.onLLMStart
- Defined in langchain-core/src/tracers/console.ts:166

onRetrieverEnd

onRetrieverEnd(run): void
Method used to log the end of a retriever run.
Parameters
- run: Run
  The retriever run that has ended.
Returns void
void
Overrides BaseTracer.onRetrieverEnd
- Defined in langchain-core/src/tracers/console.ts:288

onRetrieverError

onRetrieverError(run): void
Method used to log any errors of a retriever run.
Parameters
- run: Run
  The retriever run that has errored.
Returns void
void
Overrides BaseTracer.onRetrieverError
- Defined in langchain-core/src/tracers/console.ts:305

onRetrieverStart

onRetrieverStart(run): void
Method used to log the start of a retriever run.
Parameters
- run: Run
  The retriever run that has started.
Returns void
void
Overrides BaseTracer.onRetrieverStart
- Defined in langchain-core/src/tracers/console.ts:270

`Optional`onRunCreate

onRunCreate(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
Inherited from BaseTracer.onRunCreate
- Defined in langchain-core/src/tracers/base.ts:713

`Optional`onRunUpdate

onRunUpdate(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
Inherited from BaseTracer.onRunUpdate
- Defined in langchain-core/src/tracers/base.ts:715

`Optional`onText

onText(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
Inherited from BaseTracer.onText
- Defined in langchain-core/src/tracers/base.ts:745

onToolEnd

onToolEnd(run): void
Method used to log the end of a tool run.
Parameters
- run: Run
  The tool run that has ended.
Returns void
void
Overrides BaseTracer.onToolEnd
- Defined in langchain-core/src/tracers/console.ts:236

onToolError

onToolError(run): void
Method used to log any errors of a tool run.
Parameters
- run: Run
  The tool run that has errored.
Returns void
void
Overrides BaseTracer.onToolError
- Defined in langchain-core/src/tracers/console.ts:253

onToolStart

onToolStart(run): void
Method used to log the start of a tool run.
Parameters
- run: Run
  The tool run that has started.
Returns void
void
Overrides BaseTracer.onToolStart
- Defined in langchain-core/src/tracers/console.ts:219

`Protected`persistRun

persistRun(_run): Promise<void>
Method used to persist the run. In this case, it simply returns a resolved promise as there's no persistence logic.
Parameters
- _run: Run
  The run to persist.
Returns Promise<void>
A resolved promise.
Overrides BaseTracer.persistRun
- Defined in langchain-core/src/tracers/console.ts:64

`Protected`stringifyError

stringifyError(error): string
Parameters
- error: unknown
Returns string
Inherited from BaseTracer.stringifyError
- Defined in langchain-core/src/tracers/base.ts:78

toJSON

toJSON(): Serialized
Returns Serialized
Inherited from BaseTracer.toJSON
- Defined in langchain-core/src/callbacks/base.ts:377

toJSONNotImplemented

toJSONNotImplemented(): SerializedNotImplemented
Returns SerializedNotImplemented
Inherited from BaseTracer.toJSONNotImplemented
- Defined in langchain-core/src/callbacks/base.ts:381

`Static`fromMethods

fromMethods(methods): Handler
Parameters
- methods: BaseCallbackHandlerMethodsClass
Returns Handler
Inherited from BaseTracer.fromMethods
- Defined in langchain-core/src/callbacks/base.ts:385

Class ConsoleCallbackHandler

Example

Hierarchy (view full)

Index

Constructors

Properties

Methods

Constructors

constructor

Parameters

Returns ConsoleCallbackHandler

Properties

awaitHandlers

ignoreAgent

ignoreChain

ignoreCustomEvent

ignoreLLM

ignoreRetriever

name

raiseError

ProtectedrunMap

Methods

copy

Returns this

getBreadcrumbs

Parameters

Returns string

getParents

Parameters

Returns Run[]

handleAgentAction

Parameters

Returns Promise<void>

handleAgentEnd

Parameters

Returns Promise<void>

handleChainEnd

Parameters

Optionalinputs?: Record<string, unknown>

Returns Promise<Run>

handleChainError

Parameters

Optionalinputs?: Record<string, unknown>

Returns Promise<Run>

handleChainStart

Parameters

Returns Promise<Run>

handleChatModelStart

Parameters

Returns Promise<Run>

OptionalhandleCustomEvent

Parameters

Returns any

handleLLMEnd

Parameters

Returns Promise<Run>

handleLLMError

Parameters

Returns Promise<Run>

handleLLMNewToken

Parameters

Returns Promise<Run>

handleLLMStart

Parameters

Returns Promise<Run>

handleRetrieverEnd

Parameters

Returns Promise<Run>

handleRetrieverError

Parameters

Returns Promise<Run>

handleRetrieverStart

Parameters

Returns Promise<Run>

handleText

Parameters

Returns Promise<void>

handleToolEnd

Parameters

Returns Promise<Run>

`Protected`runMap

`Optional`inputs?: Record<string, unknown>

`Optional`inputs?: Record<string, unknown>

`Optional`handleCustomEvent

`Optional`onAgentEnd

`Optional`onLLMNewToken

`Optional`onRunCreate

`Optional`onRunUpdate

`Optional`onText

`Protected`persistRun

`Protected`stringifyError