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

BaseTracer
- ConsoleCallbackHandler

Constructors

constructor

new ConsoleCallbackHandler(_fields?): ConsoleCallbackHandler
Parameters
- Optional _fields: BaseCallbackHandlerInput
Returns ConsoleCallbackHandler
Inherited from BaseTracer.constructor
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:50

Properties

awaitHandlers

awaitHandlers: boolean = ...

ignoreAgent

ignoreAgent: boolean = false

ignoreChain

ignoreChain: boolean = false

ignoreLLM

ignoreLLM: boolean = false

ignoreRetriever

ignoreRetriever: boolean = false

name

name: "console_callback_handler" = ...

`Protected` runMap

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

Methods

copy

copy(): ConsoleCallbackHandler
Returns ConsoleCallbackHandler
Inherited from BaseTracer.copy
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:54

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:84

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:63

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 docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:378

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 docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:394

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[]
- Optional kwargs: {
  inputs?: Record<string, unknown>;
  }
  - Optional inputs?: Record<string, unknown>
Returns Promise<Run>
Inherited from BaseTracer.handleChainEnd
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:259

handleChainError

handleChainError(error, runId, _parentRunId?, _tags?, kwargs?): Promise<Run>
Called if a Chain run encounters an error
Parameters
- error: Error
- runId: string
- Optional _parentRunId: string
- Optional _tags: string[]
- Optional kwargs: {
  inputs?: Record<string, unknown>;
  }
  - Optional inputs?: Record<string, unknown>
Returns Promise<Run>
Inherited from BaseTracer.handleChainError
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:284

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
- Optional parentRunId: string
- Optional tags: string[]
- Optional metadata: KVMap
- Optional runType: string
- Optional name: string
Returns Promise<Run>
Inherited from BaseTracer.handleChainStart
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:222

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
- Optional parentRunId: string
- Optional extraParams: KVMap
- Optional tags: string[]
- Optional metadata: KVMap
- Optional name: string
Returns Promise<Run>
Inherited from BaseTracer.handleChatModelStart
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:149

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 docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:190

handleLLMError

handleLLMError(error, runId): Promise<Run>
Called if an LLM/ChatModel run encounters an error
Parameters
- error: Error
- runId: string
Returns Promise<Run>
Inherited from BaseTracer.handleLLMError
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:206

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[]
- Optional fields: HandleLLMNewTokenCallbackFields
Returns Promise<Run>
Inherited from BaseTracer.handleLLMNewToken
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:492

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
- Optional parentRunId: string
- Optional extraParams: KVMap
- Optional tags: string[]
- Optional metadata: KVMap
- Optional name: string
Returns Promise<Run>
Inherited from BaseTracer.handleLLMStart
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:108

handleRetrieverEnd

handleRetrieverEnd(documents, runId): Promise<Run>
Parameters
- documents: Document<Record<string, unknown>>[]
- runId: string
Returns Promise<Run>
Inherited from BaseTracer.handleRetrieverEnd
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:444

handleRetrieverError

handleRetrieverError(error, runId): Promise<Run>
Parameters
- error: Error
- runId: string
Returns Promise<Run>
Inherited from BaseTracer.handleRetrieverError
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:463

handleRetrieverStart

handleRetrieverStart(retriever, query, runId, parentRunId?, tags?, metadata?, name?): Promise<Run>
Parameters
- retriever: Serialized
- query: string
- runId: string
- Optional parentRunId: string
- Optional tags: string[]
- Optional metadata: KVMap
- Optional name: string
Returns Promise<Run>
Inherited from BaseTracer.handleRetrieverStart
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:407

handleText

handleText(text, runId): Promise<void>
Parameters
- text: string
- runId: string
Returns Promise<void>
Inherited from BaseTracer.handleText
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:479

handleToolEnd

handleToolEnd(output, runId): Promise<Run>
Called at the end of a Tool run, with the tool output and the run ID.
Parameters
- output: string
- runId: string
Returns Promise<Run>
Inherited from BaseTracer.handleToolEnd
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:346

handleToolError

handleToolError(error, runId): Promise<Run>
Called if a Tool run encounters an error
Parameters
- error: Error
- runId: string
Returns Promise<Run>
Inherited from BaseTracer.handleToolError
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:362

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
- Optional parentRunId: string
- Optional tags: string[]
- Optional metadata: KVMap
- Optional name: string
Returns Promise<Run>
Inherited from BaseTracer.handleToolStart
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:309

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:305

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:120

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:137

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:102

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:176

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:193

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:154

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:271

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:288

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:253

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:222

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:236

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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:207

toJSON

toJSON(): Serialized
Returns Serialized
Inherited from BaseTracer.toJSON
- Defined in docs/api_refs/langchain/src/callbacks/base.ts:364

toJSONNotImplemented

toJSONNotImplemented(): SerializedNotImplemented
Returns SerializedNotImplemented
Inherited from BaseTracer.toJSONNotImplemented
- Defined in docs/api_refs/langchain/src/callbacks/base.ts:368

`Optional` onAgentEnd

onAgentEnd(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
Inherited from BaseTracer.onAgentEnd
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:541

`Optional` onLLMNewToken

onLLMNewToken(run, token): void | Promise<void>
Parameters
- run: Run
- token: string
Returns void | Promise<void>
Inherited from BaseTracer.onLLMNewToken
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:551

`Optional` onRunCreate

onRunCreate(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
Inherited from BaseTracer.onRunCreate
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:517

`Optional` onRunUpdate

onRunUpdate(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
Inherited from BaseTracer.onRunUpdate
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:519

`Optional` onText

onText(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
Inherited from BaseTracer.onText
- Defined in docs/api_refs/langchain/src/callbacks/handlers/tracer.ts:549

`Static` fromMethods

fromMethods(methods): Handler
Parameters
- methods: BaseCallbackHandlerMethodsClass
Returns Handler
Inherited from BaseTracer.fromMethods
- Defined in docs/api_refs/langchain/src/callbacks/base.ts:372

`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 docs/api_refs/langchain/src/callbacks/handlers/console.ts:52

Class ConsoleCallbackHandler

Example

Hierarchy

Index

Constructors

Properties

Methods

Constructors

constructor

Parameters

Optional _fields: BaseCallbackHandlerInput

Returns ConsoleCallbackHandler

Properties

awaitHandlers

ignoreAgent

ignoreChain

ignoreLLM

ignoreRetriever

name

Protected runMap

Methods

copy

Returns ConsoleCallbackHandler

getBreadcrumbs

Parameters

run: Run

Returns string

getParents

Parameters

run: Run

Returns Run[]

handleAgentAction

Parameters

action: AgentAction

runId: string

Returns Promise<void>

handleAgentEnd

Parameters

action: AgentFinish

runId: string

Returns Promise<void>

handleChainEnd

Parameters

outputs: ChainValues

runId: string

Optional _parentRunId: string

Optional _tags: string[]

Optional kwargs: { inputs?: Record<string, unknown>; }

Optional inputs?: Record<string, unknown>

Returns Promise<Run>

handleChainError

Parameters

error: Error

runId: string

Optional _parentRunId: string

Optional _tags: string[]

Optional kwargs: { inputs?: Record<string, unknown>; }

Optional inputs?: Record<string, unknown>

Returns Promise<Run>

handleChainStart

Parameters

chain: Serialized

inputs: ChainValues

runId: string

Optional parentRunId: string

Optional tags: string[]

Optional metadata: KVMap

Optional runType: string

Optional name: string

Returns Promise<Run>

handleChatModelStart

Parameters

llm: Serialized

messages: BaseMessage[][]

runId: string

Optional parentRunId: string

Optional extraParams: KVMap

Optional tags: string[]

Optional metadata: KVMap

Optional name: string

`Optional` _fields: BaseCallbackHandlerInput

`Protected` runMap

`Optional` _parentRunId: string

`Optional` _tags: string[]

`Optional` kwargs: {
inputs?: Record<string, unknown>;
}

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

`Optional` _parentRunId: string

`Optional` _tags: string[]

`Optional` kwargs: {
inputs?: Record<string, unknown>;
}

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

`Optional` parentRunId: string

`Optional` tags: string[]

`Optional` metadata: KVMap

`Optional` runType: string

`Optional` name: string

`Optional` parentRunId: string

`Optional` extraParams: KVMap

`Optional` tags: string[]

`Optional` metadata: KVMap

`Optional` name: string

`Optional` _parentRunId: string

`Optional` _tags: string[]

`Optional` fields: HandleLLMNewTokenCallbackFields

`Optional` parentRunId: string

`Optional` extraParams: KVMap

`Optional` tags: string[]

`Optional` metadata: KVMap

`Optional` name: string

`Optional` parentRunId: string

`Optional` tags: string[]

`Optional` metadata: KVMap

`Optional` name: string