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*   [](/v0.1/)
*   [Components](/v0.1/docs/integrations/components/)
*   [Chat Memory](/v0.1/docs/integrations/chat_memory/)
*   Postgres Chat Memory

Postgres Chat Memory
====================

For longer-term persistence across chat sessions, you can swap out the default in-memory `chatHistory` for a [Postgres](https://www.postgresql.org/) Database.

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

First install the [node-postgres](https://node-postgres.com/) package:

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 pg

    yarn add @langchain/openai @langchain/community pg

    pnpm add @langchain/openai @langchain/community pg

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

Each chat history session is stored in a Postgres database and requires a session id.

The connection to postgres is handled through a pool. You can either pass an instance of a pool via the `pool` parameter or pass a pool config via the `poolConfig` parameter. See [pg-node docs on pools](https://node-postgres.com/apis/pool) for more information. A provided pool takes precedence, thus if both a pool instance and a pool config are passed, only the pool will be used.

    import pg from "pg";import { PostgresChatMessageHistory } from "@langchain/community/stores/message/postgres";import { ChatOpenAI } from "@langchain/openai";import { RunnableWithMessageHistory } from "@langchain/core/runnables";import {  ChatPromptTemplate,  MessagesPlaceholder,} from "@langchain/core/prompts";import { StringOutputParser } from "@langchain/core/output_parsers";const poolConfig = {  host: "127.0.0.1",  port: 5432,  user: "myuser",  password: "ChangeMe",  database: "api",};const pool = new pg.Pool(poolConfig);const model = new ChatOpenAI();const prompt = ChatPromptTemplate.fromMessages([  [    "system",    "You are a helpful assistant. Answer all questions to the best of your ability.",  ],  new MessagesPlaceholder("chat_history"),  ["human", "{input}"],]);const chain = prompt.pipe(model).pipe(new StringOutputParser());const chainWithHistory = new RunnableWithMessageHistory({  runnable: chain,  inputMessagesKey: "input",  historyMessagesKey: "chat_history",  getMessageHistory: async (sessionId) => {    const chatHistory = new PostgresChatMessageHistory({      sessionId,      pool,      // Can also pass `poolConfig` to initialize the pool internally,      // but easier to call `.end()` at the end later.    });    return chatHistory;  },});const res1 = await chainWithHistory.invoke(  {    input: "Hi! I'm MJDeligan.",  },  { configurable: { sessionId: "langchain-test-session" } });console.log(res1);/*  "Hello MJDeligan! It's nice to meet you. My name is AI. How may I assist you today?"*/const res2 = await chainWithHistory.invoke(  { input: "What did I just say my name was?" },  { configurable: { sessionId: "langchain-test-session" } });console.log(res2);/*  "You said your name was MJDeligan."*/// If you provided a pool config you should close the created pool when you are doneawait pool.end();

#### API Reference:

*   [PostgresChatMessageHistory](https://api.js.langchain.com/classes/langchain_community_stores_message_postgres.PostgresChatMessageHistory.html) from `@langchain/community/stores/message/postgres`
*   [ChatOpenAI](https://api.js.langchain.com/classes/langchain_openai.ChatOpenAI.html) from `@langchain/openai`
*   [RunnableWithMessageHistory](https://api.js.langchain.com/classes/langchain_core_runnables.RunnableWithMessageHistory.html) from `@langchain/core/runnables`
*   [ChatPromptTemplate](https://api.js.langchain.com/classes/langchain_core_prompts.ChatPromptTemplate.html) from `@langchain/core/prompts`
*   [MessagesPlaceholder](https://api.js.langchain.com/classes/langchain_core_prompts.MessagesPlaceholder.html) from `@langchain/core/prompts`
*   [StringOutputParser](https://api.js.langchain.com/classes/langchain_core_output_parsers.StringOutputParser.html) from `@langchain/core/output_parsers`

* * *

#### Help us out by providing feedback on this documentation page:

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