DynamoDB 支持的聊天记忆

为了在聊天会话之间实现更长期的持久性，您可以将支持聊天记忆类的默认内存中 chatHistory（例如 BufferMemory）替换为 DynamoDB 实例。

设置

首先，在您的项目中安装 AWS DynamoDB 客户端

npm

npm install @aws-sdk/client-dynamodb

Yarn

yarn add @aws-sdk/client-dynamodb

pnpm

pnpm add @aws-sdk/client-dynamodb

提示

查看 此部分了解有关安装集成包的一般说明。

npm

npm install @langchain/openai @langchain/community @langchain/core

Yarn

yarn add @langchain/openai @langchain/community @langchain/core

pnpm

pnpm add @langchain/openai @langchain/community @langchain/core

接下来，登录您的 AWS 帐户并创建一个 DynamoDB 表。将表命名为 langchain，并将您的分区键命名为 id。确保您的分区键是字符串。您可以将排序键和其他设置保留原样。

您还需要为具有对该表访问权限的角色或用户检索 AWS 访问密钥和秘密密钥，并将它们添加到您的环境变量中。

用法

import { BufferMemory } from "langchain/memory";
import { DynamoDBChatMessageHistory } from "@langchain/community/stores/message/dynamodb";
import { ChatOpenAI } from "@langchain/openai";
import { ConversationChain } from "langchain/chains";

const memory = new BufferMemory({
  chatHistory: new DynamoDBChatMessageHistory({
    tableName: "langchain",
    partitionKey: "id",
    sessionId: new Date().toISOString(), // Or some other unique identifier for the conversation
    config: {
      region: "us-east-2",
      credentials: {
        accessKeyId: "<your AWS access key id>",
        secretAccessKey: "<your AWS secret access key>",
      },
    },
  }),
});

const model = new ChatOpenAI();
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."
  }
}
*/

API 参考

• BufferMemory 来自 langchain/memory
• DynamoDBChatMessageHistory 来自 @langchain/community/stores/message/dynamodb
• ChatOpenAI 来自 @langchain/openai
• ConversationChain 来自 langchain/chains