@langchain/core

import type { ChainValues } from "../utils/types/index.js"; import type { BaseMessage } from "../messages/base.js"; import type { AgentAction, AgentFinish } from "../agents.js"; import type { ChatGenerationChunk, GenerationChunk, LLMResult } from "../outputs.js"; import { Serializable, Serialized, SerializedNotImplemented } from "../load/serializable.js"; import type { SerializedFields } from "../load/map_keys.js"; import type { DocumentInterface } from "../documents/document.js"; type Error = any; /** * Interface for the input parameters of the BaseCallbackHandler class. It * allows to specify which types of events should be ignored by the * callback handler. */ export interface BaseCallbackHandlerInput { ignoreLLM?: boolean; ignoreChain?: boolean; ignoreAgent?: boolean; ignoreRetriever?: boolean; ignoreCustomEvent?: boolean; _awaitHandler?: boolean; raiseError?: boolean; } /** * Interface for the indices of a new token produced by an LLM or Chat * Model in streaming mode. */ export interface NewTokenIndices { prompt: number; completion: number; } export type HandleLLMNewTokenCallbackFields = { chunk?: GenerationChunk | ChatGenerationChunk; }; /** * Abstract class that provides a set of optional methods that can be * overridden in derived classes to handle various events during the * execution of a LangChain application. */ declare abstract class BaseCallbackHandlerMethodsClass { /** * Called at the start of an LLM or Chat Model run, with the prompt(s) * and the run ID. */ handleLLMStart?(llm: Serialized, prompts: string[], runId: string, parentRunId?: string, extraParams?: Record<string, unknown>, tags?: string[], metadata?: Record<string, unknown>, runName?: string): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called when an LLM/ChatModel in `streaming` mode produces a new token */ handleLLMNewToken?(token: string, /** * 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) */ idx: NewTokenIndices, runId: string, parentRunId?: string, tags?: string[], fields?: HandleLLMNewTokenCallbackFields): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called if an LLM/ChatModel run encounters an error */ handleLLMError?(err: Error, runId: string, parentRunId?: string, tags?: string[], extraParams?: Record<string, unknown>): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called at the end of an LLM/ChatModel run, with the output and the run ID. */ handleLLMEnd?(output: LLMResult, runId: string, parentRunId?: string, tags?: string[], extraParams?: Record<string, unknown>): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called at the start of a Chat Model run, with the prompt(s) * and the run ID. */ handleChatModelStart?(llm: Serialized, messages: BaseMessage[][], runId: string, parentRunId?: string, extraParams?: Record<string, unknown>, tags?: string[], metadata?: Record<string, unknown>, runName?: string): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called at the start of a Chain run, with the chain name and inputs * and the run ID. */ handleChainStart?(chain: Serialized, inputs: ChainValues, runId: string, parentRunId?: string, tags?: string[], metadata?: Record<string, unknown>, runType?: string, runName?: string): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called if a Chain run encounters an error */ handleChainError?(err: Error, runId: string, parentRunId?: string, tags?: string[], kwargs?: { inputs?: Record<string, unknown>; }): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called at the end of a Chain run, with the outputs and the run ID. */ handleChainEnd?(outputs: ChainValues, runId: string, parentRunId?: string, tags?: string[], kwargs?: { inputs?: Record<string, unknown>; }): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called at the start of a Tool run, with the tool name and input * and the run ID. */ handleToolStart?(tool: Serialized, input: string, runId: string, parentRunId?: string, tags?: string[], metadata?: Record<string, unknown>, runName?: string): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called if a Tool run encounters an error */ handleToolError?(err: Error, runId: string, parentRunId?: string, tags?: string[]): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called at the end of a Tool run, with the tool output and the run ID. */ handleToolEnd?(output: any, runId: string, parentRunId?: string, tags?: string[]): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; handleText?(text: string, runId: string, parentRunId?: string, tags?: string[]): Promise<void> | void; /** * Called when an agent is about to execute an action, * with the action and the run ID. */ handleAgentAction?(action: AgentAction, runId: string, parentRunId?: string, tags?: string[]): Promise<void> | void; /** * Called when an agent finishes execution, before it exits. * with the final output and the run ID. */ handleAgentEnd?(action: AgentFinish, runId: string, parentRunId?: string, tags?: string[]): Promise<void> | void; handleRetrieverStart?(retriever: Serialized, query: string, runId: string, parentRunId?: string, tags?: string[], metadata?: Record<string, unknown>, name?: string): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; handleRetrieverEnd?(documents: DocumentInterface[], runId: string, parentRunId?: string, tags?: string[]): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; handleRetrieverError?(err: Error, runId: string, parentRunId?: string, tags?: string[]): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; handleCustomEvent?(eventName: string, data: any, runId: string, tags?: string[], metadata?: Record<string, any>): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; } /** * Base interface for callbacks. All methods are optional. If a method is not * implemented, it will be ignored. If a method is implemented, it will be * called at the appropriate time. All methods are called with the run ID of * the LLM/ChatModel/Chain that is running, which is generated by the * CallbackManager. * * @interface */ export type CallbackHandlerMethods = BaseCallbackHandlerMethodsClass; /** * Interface for handlers that can indicate a preference for streaming responses. * When implemented, this allows the handler to signal whether it prefers to receive * streaming responses from language models rather than complete responses. */ export interface CallbackHandlerPrefersStreaming { readonly lc_prefer_streaming: boolean; } export declare function callbackHandlerPrefersStreaming(x: BaseCallbackHandler): unknown; /** * 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. */ export declare abstract class BaseCallbackHandler extends BaseCallbackHandlerMethodsClass implements BaseCallbackHandlerInput, Serializable { lc_serializable: boolean; get lc_namespace(): ["langchain_core", "callbacks", string]; get lc_secrets(): { [key: string]: string; } | undefined; get lc_attributes(): { [key: string]: string; } | undefined; get lc_aliases(): { [key: string]: string; } | undefined; get lc_serializable_keys(): string[] | undefined; /** * 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. */ static lc_name(): string; /** * The final serialized identifier for the module. */ get lc_id(): string[]; lc_kwargs: SerializedFields; abstract name: string; ignoreLLM: boolean; ignoreChain: boolean; ignoreAgent: boolean; ignoreRetriever: boolean; ignoreCustomEvent: boolean; raiseError: boolean; awaitHandlers: boolean; constructor(input?: BaseCallbackHandlerInput); copy(): BaseCallbackHandler; toJSON(): Serialized; toJSONNotImplemented(): SerializedNotImplemented; static fromMethods(methods: CallbackHandlerMethods): { name: string; lc_serializable: boolean; readonly lc_namespace: ["langchain_core", "callbacks", string]; readonly lc_secrets: { [key: string]: string; } | undefined; readonly lc_attributes: { [key: string]: string; } | undefined; readonly lc_aliases: { [key: string]: string; } | undefined; readonly lc_serializable_keys: string[] | undefined; /** * The final serialized identifier for the module. */ readonly lc_id: string[]; lc_kwargs: SerializedFields; ignoreLLM: boolean; ignoreChain: boolean; ignoreAgent: boolean; ignoreRetriever: boolean; ignoreCustomEvent: boolean; raiseError: boolean; awaitHandlers: boolean; copy(): BaseCallbackHandler; toJSON(): Serialized; toJSONNotImplemented(): SerializedNotImplemented; /** * Called at the start of an LLM or Chat Model run, with the prompt(s) * and the run ID. */ handleLLMStart?(llm: Serialized, prompts: string[], runId: string, parentRunId?: string, extraParams?: Record<string, unknown>, tags?: string[], metadata?: Record<string, unknown>, runName?: string): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called when an LLM/ChatModel in `streaming` mode produces a new token */ handleLLMNewToken?(token: string, idx: NewTokenIndices, runId: string, parentRunId?: string, tags?: string[], fields?: HandleLLMNewTokenCallbackFields): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called if an LLM/ChatModel run encounters an error */ handleLLMError?(err: Error, runId: string, parentRunId?: string, tags?: string[], extraParams?: Record<string, unknown>): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called at the end of an LLM/ChatModel run, with the output and the run ID. */ handleLLMEnd?(output: LLMResult, runId: string, parentRunId?: string, tags?: string[], extraParams?: Record<string, unknown>): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called at the start of a Chat Model run, with the prompt(s) * and the run ID. */ handleChatModelStart?(llm: Serialized, messages: BaseMessage[][], runId: string, parentRunId?: string, extraParams?: Record<string, unknown>, tags?: string[], metadata?: Record<string, unknown>, runName?: string): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called at the start of a Chain run, with the chain name and inputs * and the run ID. */ handleChainStart?(chain: Serialized, inputs: ChainValues, runId: string, parentRunId?: string, tags?: string[], metadata?: Record<string, unknown>, runType?: string, runName?: string): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called if a Chain run encounters an error */ handleChainError?(err: Error, runId: string, parentRunId?: string, tags?: string[], kwargs?: { inputs?: Record<string, unknown>; }): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called at the end of a Chain run, with the outputs and the run ID. */ handleChainEnd?(outputs: ChainValues, runId: string, parentRunId?: string, tags?: string[], kwargs?: { inputs?: Record<string, unknown>; }): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called at the start of a Tool run, with the tool name and input * and the run ID. */ handleToolStart?(tool: Serialized, input: string, runId: string, parentRunId?: string, tags?: string[], metadata?: Record<string, unknown>, runName?: string): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called if a Tool run encounters an error */ handleToolError?(err: Error, runId: string, parentRunId?: string, tags?: string[]): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; /** * Called at the end of a Tool run, with the tool output and the run ID. */ handleToolEnd?(output: any, runId: string, parentRunId?: string, tags?: string[]): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; handleText?(text: string, runId: string, parentRunId?: string, tags?: string[]): Promise<void> | void; /** * Called when an agent is about to execute an action, * with the action and the run ID. */ handleAgentAction?(action: AgentAction, runId: string, parentRunId?: string, tags?: string[]): Promise<void> | void; /** * Called when an agent finishes execution, before it exits. * with the final output and the run ID. */ handleAgentEnd?(action: AgentFinish, runId: string, parentRunId?: string, tags?: string[]): Promise<void> | void; handleRetrieverStart?(retriever: Serialized, query: string, runId: string, parentRunId?: string, tags?: string[], metadata?: Record<string, unknown>, name?: string): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; handleRetrieverEnd?(documents: DocumentInterface[], runId: string, parentRunId?: string, tags?: string[]): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; handleRetrieverError?(err: Error, runId: string, parentRunId?: string, tags?: string[]): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; handleCustomEvent?(eventName: string, data: any, runId: string, tags?: string[], metadata?: Record<string, any>): // eslint-disable-next-line @typescript-eslint/no-explicit-any Promise<any> | any; }; } export declare const isBaseCallbackHandler: (x: unknown) => boolean; export {};