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*   [Providers](/v0.1/docs/integrations/platforms/)
    
    *   [Providers](/v0.1/docs/integrations/platforms/)
    *   [Anthropic](/v0.1/docs/integrations/platforms/anthropic/)
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*   [Components](/v0.1/docs/integrations/components/)
    
    *   [LLMs](/v0.1/docs/integrations/llms/)
        
    *   [Chat models](/v0.1/docs/integrations/chat/)
        
    *   [Document loaders](/v0.1/docs/integrations/document_loaders/)
        
    *   [Document transformers](/v0.1/docs/integrations/document_transformers/)
        
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    *   [Agents and toolkits](/v0.1/docs/integrations/toolkits/)
        
    *   [Chat Memory](/v0.1/docs/integrations/chat_memory/)
        
        *   [Astra DB Chat Memory](/v0.1/docs/integrations/chat_memory/astradb/)
        *   [Cassandra Chat Memory](/v0.1/docs/integrations/chat_memory/cassandra/)
        *   [Cloudflare D1-Backed Chat Memory](/v0.1/docs/integrations/chat_memory/cloudflare_d1/)
        *   [Convex Chat Memory](/v0.1/docs/integrations/chat_memory/convex/)
        *   [DynamoDB-Backed Chat Memory](/v0.1/docs/integrations/chat_memory/dynamodb/)
        *   [Firestore Chat Memory](/v0.1/docs/integrations/chat_memory/firestore/)
        *   [IPFS Datastore Chat Memory](/v0.1/docs/integrations/chat_memory/ipfs_datastore/)
        *   [Momento-Backed Chat Memory](/v0.1/docs/integrations/chat_memory/momento/)
        *   [MongoDB Chat Memory](/v0.1/docs/integrations/chat_memory/mongodb/)
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        *   [Xata Chat Memory](/v0.1/docs/integrations/chat_memory/xata/)
        *   [Zep Memory](/v0.1/docs/integrations/chat_memory/zep_memory/)
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*   [](/v0.1/)
*   [Components](/v0.1/docs/integrations/components/)
*   [Chat Memory](/v0.1/docs/integrations/chat_memory/)
*   Momento-Backed Chat Memory

Momento-Backed Chat Memory
==========================

For distributed, serverless persistence across chat sessions, you can swap in a [Momento](https://gomomento.com/)\-backed chat message history. Because a Momento cache is instantly available and requires zero infrastructure maintenance, it's a great way to get started with chat history whether building locally or in production.

Setup[​](#setup "Direct link to Setup")
---------------------------------------

You will need to install the [Momento Client Library](https://github.com/momentohq/client-sdk-javascript) in your project. Given Momento's compatibility with Node.js, browser, and edge environments, ensure you install the relevant package.

To install for **Node.js**:

*   npm
*   Yarn
*   pnpm

    npm install @gomomento/sdk

    yarn add @gomomento/sdk

    pnpm add @gomomento/sdk

To install for **browser/edge workers**:

*   npm
*   Yarn
*   pnpm

    npm install @gomomento/sdk-web

    yarn add @gomomento/sdk-web

    pnpm add @gomomento/sdk-web

tip

See [this section for general instructions on installing integration packages](/v0.1/docs/get_started/installation/#installing-integration-packages).

*   npm
*   Yarn
*   pnpm

    npm install @langchain/openai @langchain/community

    yarn add @langchain/openai @langchain/community

    pnpm add @langchain/openai @langchain/community

You will also need an API key from [Momento](https://gomomento.com/). You can sign up for a free account [here](https://console.gomomento.com/).

Usage[​](#usage "Direct link to Usage")
---------------------------------------

To distinguish one chat history session from another, we need a unique `sessionId`. You may also provide an optional `sessionTtl` to make sessions expire after a given number of seconds.

    import {  CacheClient,  Configurations,  CredentialProvider,} from "@gomomento/sdk"; // `from "gomomento/sdk-web";` for browser/edgeimport { BufferMemory } from "langchain/memory";import { ChatOpenAI } from "@langchain/openai";import { ConversationChain } from "langchain/chains";import { MomentoChatMessageHistory } from "@langchain/community/stores/message/momento";// See https://github.com/momentohq/client-sdk-javascript for connection optionsconst client = new CacheClient({  configuration: Configurations.Laptop.v1(),  credentialProvider: CredentialProvider.fromEnvironmentVariable({    environmentVariableName: "MOMENTO_API_KEY",  }),  defaultTtlSeconds: 60 * 60 * 24,});// Create a unique session IDconst sessionId = new Date().toISOString();const cacheName = "langchain";const memory = new BufferMemory({  chatHistory: await MomentoChatMessageHistory.fromProps({    client,    cacheName,    sessionId,    sessionTtl: 300,  }),});console.log(  `cacheName=${cacheName} and sessionId=${sessionId} . This will be used to store the chat history. You can inspect the values at your Momento console at https://console.gomomento.com.`);const model = new ChatOpenAI({  model: "gpt-3.5-turbo",  temperature: 0,});const chain = new ConversationChain({ llm: model, memory });const res1 = await chain.invoke({ input: "Hi! I'm Jim." });console.log({ res1 });/*{  res1: {    text: "Hello Jim! It's nice to meet you. My name is AI. How may I assist you today?"  }}*/const res2 = await chain.invoke({ input: "What did I just say my name was?" });console.log({ res2 });/*{  res1: {    text: "You said your name was Jim."  }}*/// See the chat history in the Momentoconsole.log(await memory.chatHistory.getMessages());

#### API Reference:

*   [BufferMemory](https://api.js.langchain.com/classes/langchain_memory.BufferMemory.html) from `langchain/memory`
*   [ChatOpenAI](https://api.js.langchain.com/classes/langchain_openai.ChatOpenAI.html) from `@langchain/openai`
*   [ConversationChain](https://api.js.langchain.com/classes/langchain_chains.ConversationChain.html) from `langchain/chains`
*   [MomentoChatMessageHistory](https://api.js.langchain.com/classes/langchain_community_stores_message_momento.MomentoChatMessageHistory.html) from `@langchain/community/stores/message/momento`

* * *

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