Firestore Chat Memory
For longer-term persistence across chat sessions, you can swap out the default in-memory chatHistory
that backs chat memory classes like BufferMemory
for a firestore.
Setup
First, install the Firebase admin package in your project:
- npm
- Yarn
- pnpm
yarn add firebase-admin
yarn add firebase-admin
yarn add firebase-admin
Go to your the Settings icon Project settings in the Firebase console. In the Your apps card, select the nickname of the app for which you need a config object. Select Config from the Firebase SDK snippet pane. Copy the config object snippet, then add it to your firebase functions FirestoreChatMessageHistory.
Usage
import { BufferMemory } from "langchain/memory";
import { FirestoreChatMessageHistory } from "langchain/stores/message/firestore";
import { ChatOpenAI } from "langchain/chat_models/openai";
import { ConversationChain } from "langchain/chains";
const memory = new BufferMemory({
chatHistory: new FirestoreChatMessageHistory({
collectionName: "langchain",
sessionId: "lc-example",
userId: "a@example.com",
config: { projectId: "your-project-id" },
}),
});
const model = new ChatOpenAI();
const chain = new ConversationChain({ llm: model, memory });
const res1 = await chain.call({ 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.call({ input: "What did I just say my name was?" });
console.log({ res2 });
/*
{
res1: {
text: "You said your name was Jim."
}
}
*/
API Reference:
- BufferMemory from
langchain/memory
- FirestoreChatMessageHistory from
langchain/stores/message/firestore
- ChatOpenAI from
langchain/chat_models/openai
- ConversationChain from
langchain/chains
Firestore Rules
If your collection name is "chathistory," you can configure Firestore rules as follows.
match /chathistory/{sessionId} {
allow read: if request.auth.uid == resource.data.createdBy;
allow write: if request.auth.uid == request.resource.data.createdBy;
}
match /chathistory/{sessionId}/messages/{messageId} {
allow read: if request.auth.uid == resource.data.createdBy;
allow write: if request.auth.uid == request.resource.data.createdBy;
}