Class BaseTracer`Abstract`

Abstract base class for creating callback handlers in the LangChain framework. It provides a set of optional methods that can be overridden in derived classes to handle various events during the execution of a LangChain application.

Hierarchy (view full)

BaseCallbackHandler
- BaseTracer

Constructors

constructor

new BaseTracer(_fields?): BaseTracer
Parameters
- Optional_fields: BaseCallbackHandlerInput
Returns BaseTracer
Overrides BaseCallbackHandler.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

`Abstract`name

name: string

raiseError

raiseError: boolean = false

`Protected`runMap

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

Methods

copy

copy(): this
Returns this
Overrides BaseCallbackHandler.copy
- Defined in langchain-core/src/tracers/base.ts:74

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>
Overrides BaseCallbackHandler.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>
Overrides BaseCallbackHandler.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>
Overrides BaseCallbackHandler.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>
Overrides BaseCallbackHandler.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>
Overrides BaseCallbackHandler.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>
Overrides BaseCallbackHandler.handleChatModelStart
- Defined in langchain-core/src/tracers/base.ts:274

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>
Overrides BaseCallbackHandler.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>
Overrides BaseCallbackHandler.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
- runId: string
- Optional_parentRunId: string
- Optional_tags: string[]
- Optionalfields: HandleLLMNewTokenCallbackFields
Returns Promise<Run>
Overrides BaseCallbackHandler.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>
Overrides BaseCallbackHandler.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>
Overrides BaseCallbackHandler.handleRetrieverEnd
- Defined in langchain-core/src/tracers/base.ts:640

handleRetrieverError

handleRetrieverError(error, runId): Promise<Run>
Parameters
- error: unknown
- runId: string
Returns Promise<Run>
Overrides BaseCallbackHandler.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>
Overrides BaseCallbackHandler.handleRetrieverStart
- Defined in langchain-core/src/tracers/base.ts:615

handleText

handleText(text, runId): Promise<void>
Parameters
- text: string
- runId: string
Returns Promise<void>
Overrides BaseCallbackHandler.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>
Overrides BaseCallbackHandler.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>
Overrides BaseCallbackHandler.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>
Overrides BaseCallbackHandler.handleToolStart
- Defined in langchain-core/src/tracers/base.ts:489

toJSON

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

toJSONNotImplemented

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

`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 langchain-core/src/callbacks/base.ts:265

`Optional`onAgentAction

onAgentAction(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
- Defined in langchain-core/src/tracers/base.ts:735

`Optional`onAgentEnd

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

`Optional`onChainEnd

onChainEnd(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
- Defined in langchain-core/src/tracers/base.ts:725

`Optional`onChainError

onChainError(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
- Defined in langchain-core/src/tracers/base.ts:727

`Optional`onChainStart

onChainStart(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
- Defined in langchain-core/src/tracers/base.ts:723

`Optional`onLLMEnd

onLLMEnd(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
- Defined in langchain-core/src/tracers/base.ts:719

`Optional`onLLMError

onLLMError(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
- Defined in langchain-core/src/tracers/base.ts:721

`Optional`onLLMNewToken

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

`Optional`onLLMStart

onLLMStart(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
- Defined in langchain-core/src/tracers/base.ts:717

`Optional`onRetrieverEnd

onRetrieverEnd(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
- Defined in langchain-core/src/tracers/base.ts:741

`Optional`onRetrieverError

onRetrieverError(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
- Defined in langchain-core/src/tracers/base.ts:743

`Optional`onRetrieverStart

onRetrieverStart(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
- Defined in langchain-core/src/tracers/base.ts:739

`Optional`onRunCreate

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

`Optional`onRunUpdate

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

`Optional`onText

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

`Optional`onToolEnd

onToolEnd(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
- Defined in langchain-core/src/tracers/base.ts:731

`Optional`onToolError

onToolError(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
- Defined in langchain-core/src/tracers/base.ts:733

`Optional`onToolStart

onToolStart(run): void | Promise<void>
Parameters
- run: Run
Returns void | Promise<void>
- Defined in langchain-core/src/tracers/base.ts:729

`Static`fromMethods

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

`Protected` `Abstract`persistRun

persistRun(run): Promise<void>
Parameters
- run: Run
Returns Promise<void>
- Defined in langchain-core/src/tracers/base.ts:91

`Protected`stringifyError

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

Class BaseTracerAbstract

Hierarchy (view full)

Index

Constructors

Properties

Methods

Constructors

constructor

Parameters

Returns BaseTracer

Properties

awaitHandlers

ignoreAgent

ignoreChain

ignoreCustomEvent

ignoreLLM

ignoreRetriever

Abstractname

raiseError

ProtectedrunMap

Methods

copy

Returns this

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>

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>

handleToolError

Parameters

Returns Promise<Run>

handleToolStart

Parameters

Returns Promise<Run>

toJSON

Returns Serialized

toJSONNotImplemented

Returns SerializedNotImplemented

Class BaseTracer`Abstract`

`Abstract`name

`Protected`runMap

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

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

`Optional`handleCustomEvent

`Optional`onAgentAction

`Optional`onAgentEnd

`Optional`onChainEnd

`Optional`onChainError

`Optional`onChainStart

`Optional`onLLMEnd

`Optional`onLLMError

`Optional`onLLMNewToken

`Optional`onLLMStart

`Optional`onRetrieverEnd

`Optional`onRetrieverError

`Optional`onRetrieverStart

`Optional`onRunCreate

`Optional`onRunUpdate

`Optional`onText

`Optional`onToolEnd

`Optional`onToolError

`Optional`onToolStart

`Static`fromMethods

`Protected` `Abstract`persistRun

`Protected`stringifyError