Class CallbackHandler

Hierarchy

BaseCallbackHandler
- CallbackHandler

Index

Constructors

constructor

Accessors

lc_aliases lc_attributes lc_id lc_namespace lc_secrets

Constructors

constructor

new CallbackHandler(params?): CallbackHandler
Parameters
- Optionalparams: ConstructorParams
Returns CallbackHandler
Overrides BaseCallbackHandler.constructor
- Defined in langfuse-langchain/src/callback.ts:76

Properties

awaitHandlers

awaitHandlers: boolean

completionStartTimes

completionStartTimes: Record<string, Date> = {}

debugEnabled

debugEnabled: boolean = false

ignoreAgent

ignoreAgent: boolean

ignoreChain

ignoreChain: boolean

ignoreCustomEvent

ignoreCustomEvent: boolean

ignoreLLM

ignoreLLM: boolean

ignoreRetriever

ignoreRetriever: boolean

langfuse

langfuse: Langfuse

lc_kwargs

lc_kwargs: SerializedFields

lc_serializable

lc_serializable: boolean

`Optional`metadata

metadata?: Record<string, unknown>

name

name: string = "CallbackHandler"

`Optional`observationId

observationId?: string

raiseError

raiseError: boolean

`Optional`rootObservationId

rootObservationId?: string

rootProvided

rootProvided: boolean = false

`Optional`sessionId

sessionId?: string

`Optional`tags

tags?: string[]

`Optional`topLevelObservationId

topLevelObservationId?: string

`Optional`traceId

traceId?: string

updateRoot

updateRoot: boolean = false

`Optional`userId

userId?: string

`Optional`version

version?: string

Accessors

lc_aliases

get lc_aliases(): undefined | {
[key: string]: string;
}
A map of aliases for constructor args. Keys are the attribute names, e.g. "foo". Values are the alias that will replace the key in serialization. This is used to eg. make argument names match Python.

Returns undefined | {
[key: string]: string;
}
Inherited from BaseCallbackHandler.lc_aliases
- Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:155

lc_attributes

get lc_attributes(): undefined | {
[key: string]: string;
}
A map of additional attributes to merge with constructor args. Keys are the attribute names, e.g. "foo". Values are the attribute values, which will be serialized. These attributes need to be accepted by the constructor as arguments.

Returns undefined | {
[key: string]: string;
}
Inherited from BaseCallbackHandler.lc_attributes
- Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:152

lc_id

get lc_id(): string[]
The final serialized identifier for the module.

Returns string[]
Inherited from BaseCallbackHandler.lc_id
- Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:168

lc_namespace

get 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.

Returns ["langchain_core", "callbacks", string]
Inherited from BaseCallbackHandler.lc_namespace
- Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:148

lc_secrets

get lc_secrets(): undefined | {
[key: string]: string;
}
A map of secrets, which will be omitted from serialization. Keys are paths to the secret in constructor args, e.g. "foo.bar.baz". Values are the secret ids, which will be used when deserializing.

Returns undefined | {
[key: string]: string;
}
Inherited from BaseCallbackHandler.lc_secrets
- Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:149

Methods

_log

_log(message): void
Parameters
- message: any
Returns void
- Defined in langfuse-langchain/src/callback.ts:114

copy

copy(): BaseCallbackHandler
Returns BaseCallbackHandler
Inherited from BaseCallbackHandler.copy
- Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:179

debug

debug(enabled?): void
Parameters
- enabled: boolean = true
Returns void
- Defined in langfuse-langchain/src/callback.ts:109

flushAsync

flushAsync(): Promise<any>
Returns Promise<any>
- Defined in langfuse-langchain/src/callback.ts:101

generateTrace

generateTrace(runName, runId, parentRunId, tags?, metadata?, input?): void
Parameters
- runName: string
- runId: string
- parentRunId: undefined | string
- Optionaltags: string[]
- Optionalmetadata: Record<string, unknown>
- Optionalinput: string | ChainValues | BaseMessage[][]
Returns void
- Defined in langfuse-langchain/src/callback.ts:314

getLangchainRunId

getLangchainRunId(): undefined | string
Returns undefined | string
- Defined in langfuse-langchain/src/callback.ts:161

getTraceId

getTraceId(): undefined | string
Returns undefined | string
Deprecated
This method will be removed in a future version as it is not concurrency-safe. Please use interop with the Langfuse SDK to get the trace ID (docs).
- Defined in langfuse-langchain/src/callback.ts:149

getTraceUrl

getTraceUrl(): undefined | string
Returns undefined | string
Deprecated
This method will be removed in a future version as it is not concurrency-safe. For more information on how to get trace URLs, see https://langfuse.com/docs/tracing/url.
- Defined in langfuse-langchain/src/callback.ts:157

handleAgentAction

handleAgentAction(action, runId?, parentRunId?): Promise<void>
Called when an agent is about to execute an action, with the action and the run ID.
Parameters
- action: AgentAction
- OptionalrunId: string
- OptionalparentRunId: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleAgentAction
- Defined in langfuse-langchain/src/callback.ts:262

`Optional`handleAgentEnd

handleAgentEnd(action, runId, parentRunId?): Promise<void>
Called when an agent finishes execution, before it exits. with the final output and the run ID.
Parameters
- action: AgentFinish
- runId: string
- OptionalparentRunId: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleAgentEnd
- Defined in langfuse-langchain/src/callback.ts:279

handleChainEnd

handleChainEnd(outputs, runId, parentRunId?): Promise<void>
Called at the end of a Chain run, with the outputs and the run ID.
Parameters
- outputs: ChainValues
- runId: string
- OptionalparentRunId: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleChainEnd
- Defined in langfuse-langchain/src/callback.ts:445

handleChainError

handleChainError(err, runId, parentRunId?): Promise<void>
Called if a Chain run encounters an error
Parameters
- err: any
- runId: string
- OptionalparentRunId: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleChainError
- Defined in langfuse-langchain/src/callback.ts:296

handleChainStart

handleChainStart(chain, inputs, runId, parentRunId?, tags?, metadata?, runType?, name?): Promise<void>
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: Record<string, unknown>
- OptionalrunType: string
- Optionalname: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleChainStart
- Defined in langfuse-langchain/src/callback.ts:182

handleChatModelStart

handleChatModelStart(llm, messages, runId, parentRunId?, extraParams?, tags?, metadata?, name?): Promise<void>
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: Record<string, unknown>
- Optionaltags: string[]
- Optionalmetadata: Record<string, unknown>
- Optionalname: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleChatModelStart
- Defined in langfuse-langchain/src/callback.ts:424

`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 BaseCallbackHandler.handleCustomEvent
- Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:127

handleGenerationStart

handleGenerationStart(llm, messages, runId, parentRunId?, extraParams?, tags?, metadata?, name?): Promise<void>
Parameters
- llm: Serialized
- messages: (MessageContent | LlmMessage | AnonymousLlmMessage)[]
- runId: string
- OptionalparentRunId: string
- OptionalextraParams: Record<string, unknown>
- Optionaltags: string[]
- Optionalmetadata: Record<string, unknown>
- Optionalname: string
Returns Promise<void>
- Defined in langfuse-langchain/src/callback.ts:356

handleLLMEnd

handleLLMEnd(output, runId, parentRunId?): Promise<void>
Called at the end of an LLM/ChatModel run, with the output and the run ID.
Parameters
- output: LLMResult
- runId: string
- OptionalparentRunId: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleLLMEnd
- Defined in langfuse-langchain/src/callback.ts:597

handleLLMError

handleLLMError(err, runId, parentRunId?): Promise<void>
Called if an LLM/ChatModel run encounters an error
Parameters
- err: any
- runId: string
- OptionalparentRunId: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleLLMError
- Defined in langfuse-langchain/src/callback.ts:703

handleLLMNewToken

handleLLMNewToken(token, _idx, runId, _parentRunId?, _tags?, _fields?): Promise<void>
Called when an LLM/ChatModel in streaming mode produces a new token
Parameters
- token: string
- _idx: any
- runId: string
- Optional_parentRunId: string
- Optional_tags: string[]
- Optional_fields: any
Returns Promise<void>
Overrides BaseCallbackHandler.handleLLMNewToken
- Defined in langfuse-langchain/src/callback.ts:129

handleLLMStart

handleLLMStart(llm, prompts, runId, parentRunId?, extraParams?, tags?, metadata?, name?): Promise<void>
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: Record<string, unknown>
- Optionaltags: string[]
- Optionalmetadata: Record<string, unknown>
- Optionalname: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleLLMStart
- Defined in langfuse-langchain/src/callback.ts:468

handleNewToken

handleNewToken(_token, runId): Promise<void>
Parameters
- _token: string
- runId: string
Returns Promise<void>
- Defined in langfuse-langchain/src/callback.ts:120

handleRetrieverEnd

handleRetrieverEnd(documents, runId, parentRunId?): Promise<void>
Parameters
- documents: Document<Record<string, any>>[]
- runId: string
- OptionalparentRunId: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleRetrieverEnd
- Defined in langfuse-langchain/src/callback.ts:541

handleRetrieverError

handleRetrieverError(err, runId, parentRunId?): Promise<void>
Parameters
- err: any
- runId: string
- OptionalparentRunId: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleRetrieverError
- Defined in langfuse-langchain/src/callback.ts:165

handleRetrieverStart

handleRetrieverStart(retriever, query, runId, parentRunId?, tags?, metadata?, name?): Promise<void>
Parameters
- retriever: Serialized
- query: string
- runId: string
- OptionalparentRunId: string
- Optionaltags: string[]
- Optionalmetadata: Record<string, unknown>
- Optionalname: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleRetrieverStart
- Defined in langfuse-langchain/src/callback.ts:514

`Optional`handleText

handleText(text, runId, parentRunId?, tags?): void | Promise<void>
Parameters
- text: string
- runId: string
- OptionalparentRunId: string
- Optionaltags: string[]
Returns void | Promise<void>
Inherited from BaseCallbackHandler.handleText
- Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:110

handleToolEnd

handleToolEnd(output, runId, parentRunId?): Promise<void>
Called at the end of a Tool run, with the tool output and the run ID.
Parameters
- output: string
- runId: string
- OptionalparentRunId: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleToolEnd
- Defined in langfuse-langchain/src/callback.ts:562

handleToolError

handleToolError(err, runId, parentRunId?): Promise<void>
Called if a Tool run encounters an error
Parameters
- err: any
- runId: string
- OptionalparentRunId: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleToolError
- Defined in langfuse-langchain/src/callback.ts:579

handleToolStart

handleToolStart(tool, input, runId, parentRunId?, tags?, metadata?, name?): Promise<void>
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: Record<string, unknown>
- Optionalname: string
Returns Promise<void>
Overrides BaseCallbackHandler.handleToolStart
- Defined in langfuse-langchain/src/callback.ts:487

joinTagsAndMetaData

joinTagsAndMetaData(tags?, metadata1?, metadata2?): undefined | Record<string, unknown>
Parameters
- Optionaltags: string[]
- Optionalmetadata1: Record<string, unknown>
- Optionalmetadata2: Record<string, unknown>
Returns undefined | Record<string, unknown>
- Defined in langfuse-langchain/src/callback.ts:738

shutdownAsync

shutdownAsync(): Promise<any>
Returns Promise<any>
- Defined in langfuse-langchain/src/callback.ts:105

toJSON

toJSON(): Serialized
Returns Serialized
Inherited from BaseCallbackHandler.toJSON
- Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:180

toJSONNotImplemented

toJSONNotImplemented(): SerializedNotImplemented
Returns SerializedNotImplemented
Inherited from BaseCallbackHandler.toJSONNotImplemented
- Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:181

updateTrace

updateTrace(runId, parentRunId, output): void
Parameters
- runId: string
- parentRunId: undefined | string
- output: any
Returns void
- Defined in langfuse-langchain/src/callback.ts:721

`Static`fromMethods

fromMethods(methods): {
    awaitHandlers: boolean;
    ignoreAgent: boolean;
    ignoreChain: boolean;
    ignoreCustomEvent: boolean;
    ignoreLLM: boolean;
    ignoreRetriever: boolean;
    lc_aliases: undefined | {
        [key: string]: string;
    };
    lc_attributes: undefined | {
        [key: string]: string;
    };
    lc_id: string[];
    lc_kwargs: SerializedFields;
    lc_namespace: ["langchain_core", "callbacks", string];
    lc_secrets: undefined | {
        [key: string]: string;
    };
    lc_serializable: boolean;
    name: string;
    raiseError: boolean;
    copy(): BaseCallbackHandler;
    handleAgentAction?(action: AgentAction, runId: string, parentRunId?: string, tags?: string[]): void | Promise<void>;
    handleAgentEnd?(action: AgentFinish, runId: string, parentRunId?: string, tags?: string[]): void | Promise<void>;
    handleChainEnd?(outputs: ChainValues, runId: string, parentRunId?: string, tags?: string[], kwargs?: {
        inputs?: Record<string, unknown>;
    }): any;
    handleChainError?(err: any, runId: string, parentRunId?: string, tags?: string[], kwargs?: {
        inputs?: Record<string, unknown>;
    }): any;
    handleChainStart?(chain: Serialized, inputs: ChainValues, runId: string, parentRunId?: string, tags?: string[], metadata?: Record<string, unknown>, runType?: string, runName?: string): any;
    handleChatModelStart?(llm: Serialized, messages: BaseMessage[][], runId: string, parentRunId?: string, extraParams?: Record<string, unknown>, tags?: string[], metadata?: Record<string, unknown>, runName?: string): any;
    handleCustomEvent?(eventName: string, data: any, runId: string, tags?: string[], metadata?: Record<string, any>): any;
    handleLLMEnd?(output: LLMResult, runId: string, parentRunId?: string, tags?: string[]): any;
    handleLLMError?(err: any, runId: string, parentRunId?: string, tags?: string[]): any;
    handleLLMNewToken?(token: string, idx: NewTokenIndices, runId: string, parentRunId?: string, tags?: string[], fields?: HandleLLMNewTokenCallbackFields): any;
    handleLLMStart?(llm: Serialized, prompts: string[], runId: string, parentRunId?: string, extraParams?: Record<string, unknown>, tags?: string[], metadata?: Record<string, unknown>, runName?: string): any;
    handleRetrieverEnd?(documents: DocumentInterface<Record<string, any>>[], runId: string, parentRunId?: string, tags?: string[]): any;
    handleRetrieverError?(err: any, runId: string, parentRunId?: string, tags?: string[]): any;
    handleRetrieverStart?(retriever: Serialized, query: string, runId: string, parentRunId?: string, tags?: string[], metadata?: Record<string, unknown>, name?: string): any;
    handleText?(text: string, runId: string, parentRunId?: string, tags?: string[]): void | Promise<void>;
    handleToolEnd?(output: any, runId: string, parentRunId?: string, tags?: string[]): any;
    handleToolError?(err: any, runId: string, parentRunId?: string, tags?: string[]): any;
    handleToolStart?(tool: Serialized, input: string, runId: string, parentRunId?: string, tags?: string[], metadata?: Record<string, unknown>, runName?: string): any;
    toJSON(): Serialized;
    toJSONNotImplemented(): SerializedNotImplemented;
}
Parameters
- methods: BaseCallbackHandlerMethodsClass
Returns {
    awaitHandlers: boolean;
    ignoreAgent: boolean;
    ignoreChain: boolean;
    ignoreCustomEvent: boolean;
    ignoreLLM: boolean;
    ignoreRetriever: boolean;
    lc_aliases: undefined | {
        [key: string]: string;
    };
    lc_attributes: undefined | {
        [key: string]: string;
    };
    lc_id: string[];
    lc_kwargs: SerializedFields;
    lc_namespace: ["langchain_core", "callbacks", string];
    lc_secrets: undefined | {
        [key: string]: string;
    };
    lc_serializable: boolean;
    name: string;
    raiseError: boolean;
    copy(): BaseCallbackHandler;
    handleAgentAction?(action: AgentAction, runId: string, parentRunId?: string, tags?: string[]): void | Promise<void>;
    handleAgentEnd?(action: AgentFinish, runId: string, parentRunId?: string, tags?: string[]): void | Promise<void>;
    handleChainEnd?(outputs: ChainValues, runId: string, parentRunId?: string, tags?: string[], kwargs?: {
        inputs?: Record<string, unknown>;
    }): any;
    handleChainError?(err: any, runId: string, parentRunId?: string, tags?: string[], kwargs?: {
        inputs?: Record<string, unknown>;
    }): any;
    handleChainStart?(chain: Serialized, inputs: ChainValues, runId: string, parentRunId?: string, tags?: string[], metadata?: Record<string, unknown>, runType?: string, runName?: string): any;
    handleChatModelStart?(llm: Serialized, messages: BaseMessage[][], runId: string, parentRunId?: string, extraParams?: Record<string, unknown>, tags?: string[], metadata?: Record<string, unknown>, runName?: string): any;
    handleCustomEvent?(eventName: string, data: any, runId: string, tags?: string[], metadata?: Record<string, any>): any;
    handleLLMEnd?(output: LLMResult, runId: string, parentRunId?: string, tags?: string[]): any;
    handleLLMError?(err: any, runId: string, parentRunId?: string, tags?: string[]): any;
    handleLLMNewToken?(token: string, idx: NewTokenIndices, runId: string, parentRunId?: string, tags?: string[], fields?: HandleLLMNewTokenCallbackFields): any;
    handleLLMStart?(llm: Serialized, prompts: string[], runId: string, parentRunId?: string, extraParams?: Record<string, unknown>, tags?: string[], metadata?: Record<string, unknown>, runName?: string): any;
    handleRetrieverEnd?(documents: DocumentInterface<Record<string, any>>[], runId: string, parentRunId?: string, tags?: string[]): any;
    handleRetrieverError?(err: any, runId: string, parentRunId?: string, tags?: string[]): any;
    handleRetrieverStart?(retriever: Serialized, query: string, runId: string, parentRunId?: string, tags?: string[], metadata?: Record<string, unknown>, name?: string): any;
    handleText?(text: string, runId: string, parentRunId?: string, tags?: string[]): void | Promise<void>;
    handleToolEnd?(output: any, runId: string, parentRunId?: string, tags?: string[]): any;
    handleToolError?(err: any, runId: string, parentRunId?: string, tags?: string[]): any;
    handleToolStart?(tool: Serialized, input: string, runId: string, parentRunId?: string, tags?: string[], metadata?: Record<string, unknown>, runName?: string): any;
    toJSON(): Serialized;
    toJSONNotImplemented(): SerializedNotImplemented;
}
- awaitHandlers: boolean
- ignoreAgent: boolean
- ignoreChain: boolean
- ignoreCustomEvent: boolean
- ignoreLLM: boolean
- ignoreRetriever: boolean
- Readonlylc_aliases: undefined | {
  [key: string]: string;
  }
- Readonlylc_attributes: undefined | {
  [key: string]: string;
  }
- Readonlylc_id: string[]
  The final serialized identifier for the module.
- lc_kwargs: SerializedFields
- Readonlylc_namespace: ["langchain_core", "callbacks", string]
- Readonlylc_secrets: undefined | {
  [key: string]: string;
  }
- lc_serializable: boolean
- name: string
- raiseError: boolean
- copy:function
  - copy(): BaseCallbackHandler
  - Returns BaseCallbackHandler
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:207
- handleAgentAction?:function
  - handleAgentAction(action, runId, parentRunId?, tags?): void | Promise<void>
  - Called when an agent is about to execute an action, with the action and the run ID.
    Parameters
    - action: AgentAction
    - runId: string
    - OptionalparentRunId: string
    - Optionaltags: string[]
    Returns void | Promise<void>
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:267
- handleAgentEnd?:function
  - handleAgentEnd(action, runId, parentRunId?, tags?): void | Promise<void>
  - Called when an agent finishes execution, before it exits. with the final output and the run ID.
    Parameters
    - action: AgentFinish
    - runId: string
    - OptionalparentRunId: string
    - Optionaltags: string[]
    Returns void | Promise<void>
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:272
- handleChainEnd?:function
  - handleChainEnd(outputs, runId, parentRunId?, tags?, kwargs?): any
  - Called at the end of a Chain run, with the outputs and the run ID.
    Parameters
    - outputs: ChainValues
    - runId: string
    - OptionalparentRunId: string
    - Optionaltags: string[]
    - Optionalkwargs: {
      inputs?: Record<string, unknown>;
      }
      Optionalinputs?: Record<string, unknown>
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:246
- handleChainError?:function
  - handleChainError(err, runId, parentRunId?, tags?, kwargs?): any
  - Called if a Chain run encounters an error
    Parameters
    - err: any
    - runId: string
    - OptionalparentRunId: string
    - Optionaltags: string[]
    - Optionalkwargs: {
      inputs?: Record<string, unknown>;
      }
      Optionalinputs?: Record<string, unknown>
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:240
- handleChainStart?:function
  - handleChainStart(chain, inputs, runId, parentRunId?, tags?, metadata?, runType?, runName?): any
  - 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: Record<string, unknown>
    - OptionalrunType: string
    - OptionalrunName: string
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:236
- handleChatModelStart?:function
  - handleChatModelStart(llm, messages, runId, parentRunId?, extraParams?, tags?, metadata?, runName?): any
  - 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: Record<string, unknown>
    - Optionaltags: string[]
    - Optionalmetadata: Record<string, unknown>
    - OptionalrunName: string
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:231
- handleCustomEvent?:function
  - handleCustomEvent(eventName, data, runId, tags?, metadata?): any
  - Parameters
    - eventName: string
    - data: any
    - runId: string
    - Optionaltags: string[]
    - Optionalmetadata: Record<string, any>
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:276
- handleLLMEnd?:function
  - handleLLMEnd(output, runId, parentRunId?, tags?): any
  - Called at the end of an LLM/ChatModel run, with the output and the run ID.
    Parameters
    - output: LLMResult
    - runId: string
    - OptionalparentRunId: string
    - Optionaltags: string[]
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:226
- handleLLMError?:function
  - handleLLMError(err, runId, parentRunId?, tags?): any
  - Called if an LLM/ChatModel run encounters an error
    Parameters
    - err: any
    - runId: string
    - OptionalparentRunId: string
    - Optionaltags: string[]
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:222
- handleLLMNewToken?:function
  - handleLLMNewToken(token, idx, runId, parentRunId?, tags?, fields?): any
  - Called when an LLM/ChatModel in streaming mode produces a new token
    Parameters
    - token: string
    - idx: NewTokenIndices
    - runId: string
    - OptionalparentRunId: string
    - Optionaltags: string[]
    - Optionalfields: HandleLLMNewTokenCallbackFields
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:218
- handleLLMStart?:function
  - handleLLMStart(llm, prompts, runId, parentRunId?, extraParams?, tags?, metadata?, runName?): any
  - 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: Record<string, unknown>
    - Optionaltags: string[]
    - Optionalmetadata: Record<string, unknown>
    - OptionalrunName: string
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:214
- handleRetrieverEnd?:function
  - handleRetrieverEnd(documents, runId, parentRunId?, tags?): any
  - Parameters
    - documents: DocumentInterface<Record<string, any>>[]
    - runId: string
    - OptionalparentRunId: string
    - Optionaltags: string[]
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:274
- handleRetrieverError?:function
  - handleRetrieverError(err, runId, parentRunId?, tags?): any
  - Parameters
    - err: any
    - runId: string
    - OptionalparentRunId: string
    - Optionaltags: string[]
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:275
- handleRetrieverStart?:function
  - handleRetrieverStart(retriever, query, runId, parentRunId?, tags?, metadata?, name?): any
  - Parameters
    - retriever: Serialized
    - query: string
    - runId: string
    - OptionalparentRunId: string
    - Optionaltags: string[]
    - Optionalmetadata: Record<string, unknown>
    - Optionalname: string
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:273
- handleText?:function
  - handleText(text, runId, parentRunId?, tags?): void | Promise<void>
  - Parameters
    - text: string
    - runId: string
    - OptionalparentRunId: string
    - Optionaltags: string[]
    Returns void | Promise<void>
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:262
- handleToolEnd?:function
  - handleToolEnd(output, runId, parentRunId?, tags?): any
  - Called at the end of a Tool run, with the tool output and the run ID.
    Parameters
    - output: any
    - runId: string
    - OptionalparentRunId: string
    - Optionaltags: string[]
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:261
- handleToolError?:function
  - handleToolError(err, runId, parentRunId?, tags?): any
  - Called if a Tool run encounters an error
    Parameters
    - err: any
    - runId: string
    - OptionalparentRunId: string
    - Optionaltags: string[]
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:257
- handleToolStart?:function
  - handleToolStart(tool, input, runId, parentRunId?, tags?, metadata?, runName?): any
  - 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: Record<string, unknown>
    - OptionalrunName: string
    Returns any
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:253
- toJSON:function
  - toJSON(): Serialized
  - Returns Serialized
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:208
- toJSONNotImplemented:function
  - toJSONNotImplemented(): SerializedNotImplemented
  - Returns SerializedNotImplemented
    - Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:209
Inherited from BaseCallbackHandler.fromMethods
- Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:182

`Static`lc_name

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.

Returns string
Inherited from BaseCallbackHandler.lc_name
- Defined in node_modules/@langchain/core/dist/callbacks/base.d.ts:164

Class CallbackHandler

Hierarchy

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Parameters

Returns CallbackHandler

Properties

awaitHandlers

completionStartTimes

debugEnabled

ignoreAgent

ignoreChain

ignoreCustomEvent

ignoreLLM

ignoreRetriever

langfuse

lc_kwargs

lc_serializable

Optionalmetadata

name

OptionalobservationId

raiseError

OptionalrootObservationId

rootProvided

OptionalsessionId

Optionaltags

OptionaltopLevelObservationId

OptionaltraceId

updateRoot

OptionaluserId

Optionalversion

Accessors

lc_aliases

Returns undefined | { [key: string]: string; }

lc_attributes

Returns undefined | { [key: string]: string; }

lc_id

Returns string[]

lc_namespace

Returns ["langchain_core", "callbacks", string]

lc_secrets

Returns undefined | { [key: string]: string; }

Methods

_log

Parameters

Returns void

copy

Returns BaseCallbackHandler

debug

Parameters

Returns void

flushAsync

Returns Promise<any>

generateTrace

Parameters

Returns void

getLangchainRunId

Returns undefined | string

getTraceId

Returns undefined | string

Deprecated

getTraceUrl

Returns undefined | string

Deprecated

handleAgentAction

Parameters

Returns Promise<void>

OptionalhandleAgentEnd

Parameters

Returns Promise<void>

handleChainEnd

Parameters

Returns Promise<void>

handleChainError

Parameters

`Optional`metadata

`Optional`observationId

`Optional`rootObservationId

`Optional`sessionId

`Optional`tags

`Optional`topLevelObservationId

`Optional`traceId

`Optional`userId

`Optional`version

Returns undefined | {
[key: string]: string;
}

Returns undefined | {
[key: string]: string;
}

Returns undefined | {
[key: string]: string;
}

`Optional`handleAgentEnd

`Optional`handleCustomEvent

`Optional`handleText

`Static`fromMethods