Abstract Optional _fields: BaseCallbackHandlerInputAbstract nameProtected runCalled when an agent is about to execute an action, with the action and the run ID.
Called when an agent finishes execution, before it exits. with the final output and the run ID.
Called at the end of a Chain run, with the outputs and the run ID.
Optional _parentRunId: stringOptional _tags: string[]Optional kwargs: { Optional inputs?: Record<string, unknown>Called if a Chain run encounters an error
Optional _parentRunId: stringOptional _tags: string[]Optional kwargs: { Optional inputs?: Record<string, unknown>Called at the start of a Chain run, with the chain name and inputs and the run ID.
Optional parentRunId: stringOptional tags: string[]Optional metadata: KVMapOptional runType: stringOptional name: stringCalled at the start of a Chat Model run, with the prompt(s) and the run ID.
Optional parentRunId: stringOptional extraParams: KVMapOptional tags: string[]Optional metadata: KVMapOptional name: stringCalled when an LLM/ChatModel in streaming mode produces a new token
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)
Optional _parentRunId: stringOptional _tags: string[]Optional fields: HandleLLMNewTokenCallbackFieldsCalled at the start of an LLM or Chat Model run, with the prompt(s) and the run ID.
Optional parentRunId: stringOptional extraParams: KVMapOptional tags: string[]Optional metadata: KVMapOptional name: stringOptional parentRunId: stringOptional tags: string[]Optional metadata: KVMapOptional name: stringCalled at the start of a Tool run, with the tool name and input and the run ID.
Optional parentRunId: stringOptional tags: string[]Optional metadata: KVMapOptional name: stringOptional onOptional onOptional onOptional onOptional onOptional onLLMEndOptional onLLMErrorOptional onLLMNewOptional kwargs: { Optional onLLMStartOptional onOptional onOptional onOptional onOptional onOptional onOptional onOptional onOptional onStatic fromProtected Abstract persistProtected stringifyGenerated using TypeDoc
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.