Class RunnableWithMessageHistory<RunInput, RunOutput>

Wraps a LCEL chain and manages history. It appends input messages and chain outputs as history, and adds the current history messages to the chain input.

Example

// yarn add @langchain/anthropic @langchain/community @upstash/redis

import {
ChatPromptTemplate,
MessagesPlaceholder,
} from "@langchain/core/prompts";
import { ChatAnthropic } from "@langchain/anthropic";
import { UpstashRedisChatMessageHistory } from "@langchain/community/stores/message/upstash_redis";
// For demos, you can also use an in-memory store:
// import { ChatMessageHistory } from "langchain/stores/message/in_memory";

const prompt = ChatPromptTemplate.fromMessages([
["system", "You're an assistant who's good at {ability}"],
new MessagesPlaceholder("history"),
["human", "{question}"],
]);

const chain = prompt.pipe(new ChatAnthropic({}));

const chainWithHistory = new RunnableWithMessageHistory({
runnable: chain,
getMessageHistory: (sessionId) =>
new UpstashRedisChatMessageHistory({
sessionId,
config: {
url: process.env.UPSTASH_REDIS_REST_URL!,
token: process.env.UPSTASH_REDIS_REST_TOKEN!,
},
}),
inputMessagesKey: "question",
historyMessagesKey: "history",
});

const result = await chainWithHistory.invoke(
{
ability: "math",
question: "What does cosine mean?",
},
{
configurable: {
sessionId: "some_string_identifying_a_user",
},
}
);

const result2 = await chainWithHistory.invoke(
{
ability: "math",
question: "What's its inverse?",
},
{
configurable: {
sessionId: "some_string_identifying_a_user",
},
}
);

Type Parameters

  • RunInput

  • RunOutput

Hierarchy

Constructors

Properties

bound: Runnable<RunInput, RunOutput, RunnableConfig>
getMessageHistory: GetSessionHistoryCallable
runnable: Runnable<RunInput, RunOutput, RunnableConfig>
configFactories?: ((config) => RunnableConfig | Promise<RunnableConfig>)[]

Type declaration

historyMessagesKey?: string
inputMessagesKey?: string
name?: string
outputMessagesKey?: string
kwargs?: Partial<RunnableConfig>

Methods

  • Assigns new fields to the dict output of this runnable. Returns a new runnable.

    Parameters

    • mapping: RunnableMapLike<Record<string, unknown>, Record<string, unknown>>

    Returns RunnableSequence<any, any>

  • Default implementation of batch, which calls invoke N times. Subclasses should override this method if they can batch more efficiently.

    Parameters

    • inputs: RunInput[]

      Array of inputs to each batch call.

    • Optional options: Partial<RunnableConfig> | Partial<RunnableConfig>[]

      Either a single call options object to apply to each batch call or an array for each call.

    • Optional batchOptions: RunnableBatchOptions & {
          returnExceptions?: false;
      }

    Returns Promise<RunOutput[]>

    An array of RunOutputs, or mixed RunOutputs and errors if batchOptions.returnExceptions is set

  • Parameters

    Returns Promise<(Error | RunOutput)[]>

  • Parameters

    Returns Promise<(Error | RunOutput)[]>

  • Parameters

    • Optional suffix: string

    Returns string

  • Parameters

    Returns Promise<RunOutput>

  • Return a new Runnable that maps a list of inputs to a list of outputs, by calling invoke() with each input.

    Returns Runnable<RunInput[], RunOutput[], RunnableConfig>

  • Pick keys from the dict output of this runnable. Returns a new runnable.

    Parameters

    • keys: string | string[]

    Returns RunnableSequence<any, any>

  • Create a new runnable sequence that runs each individual runnable in series, piping the output of one runnable into another runnable or runnable-like.

    Type Parameters

    • NewRunOutput

    Parameters

    • coerceable: RunnableLike<RunOutput, NewRunOutput>

      A runnable, function, or object whose values are functions or runnables.

    Returns RunnableSequence<RunInput, Exclude<NewRunOutput, Error>>

    A new runnable sequence.

  • Stream output in chunks.

    Parameters

    Returns Promise<IterableReadableStream<RunOutput>>

    A readable stream that is also an iterable.

  • Stream all output from a runnable, as reported to the callback system. This includes all inner runs of LLMs, Retrievers, Tools, etc. Output is streamed as Log objects, which include a list of jsonpatch ops that describe how the state of the run has changed in each step, and the final state of the run. The jsonpatch ops can be applied in order to construct state.

    Parameters

    • input: RunInput
    • Optional options: Partial<RunnableConfig>
    • Optional streamOptions: Omit<LogStreamCallbackHandlerInput, "autoClose">

    Returns AsyncGenerator<RunLogPatch, any, unknown>

  • Default implementation of transform, which buffers input and then calls stream. Subclasses should override this method if they can start producing output while input is still being generated.

    Parameters

    • generator: AsyncGenerator<RunInput, any, unknown>
    • options: Partial<RunnableConfig>

    Returns AsyncGenerator<RunOutput, any, unknown>

  • Create a new runnable from the current one that will try invoking other passed fallback runnables if the initial invocation fails.

    Parameters

    Returns RunnableWithFallbacks<RunInput, RunOutput>

    A new RunnableWithFallbacks.

  • Bind lifecycle listeners to a Runnable, returning a new Runnable. The Run object contains information about the run, including its id, type, input, output, error, startTime, endTime, and any tags or metadata added to the run.

    Parameters

    • params: {
          onEnd?: ((run, config?) => void | Promise<void>);
          onError?: ((run, config?) => void | Promise<void>);
          onStart?: ((run, config?) => void | Promise<void>);
      }

      The object containing the callback functions.

      • Optional onEnd?: ((run, config?) => void | Promise<void>)
          • (run, config?): void | Promise<void>
          • Called after the runnable finishes running, with the Run object.

            Parameters

            Returns void | Promise<void>

      • Optional onError?: ((run, config?) => void | Promise<void>)
          • (run, config?): void | Promise<void>
          • Called if the runnable throws an error, with the Run object.

            Parameters

            Returns void | Promise<void>

      • Optional onStart?: ((run, config?) => void | Promise<void>)
          • (run, config?): void | Promise<void>
          • Called before the runnable starts running, with the Run object.

            Parameters

            Returns void | Promise<void>

    Returns Runnable<RunInput, RunOutput, RunnableConfig>

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