MongoDB Chatbot Server

Chatbot server for the MongoDB Chatbot Framework.

The mongodb-chatbot-server is a npm package that provides a configurable Express.js server to quickly spin up a retrieval augmented generation (RAG) chatbot server powered by MongoDB.

The server is designed to handle the generalizable areas of a RAG server, like routing, caching, logging, and streaming. This allows you to focus on the specifics of your chatbot, like the content, prompts, and AI models.

Documentation

To learn more about the MongoDB Chatbot Server, check out the documentation.

Usage

Installation

Install the package using npm:

npm install mongodb-chatbot-server

Configuration

The mongodb-chatbot-server exports the function makeApp() which exports the Express.js app. The function takes a AppConfig object as an argument.

Here's an example configuration and server:

import "dotenv/config";
import {
  MongoClient,
  makeMongoDbEmbeddedContentStore,
  makeOpenAiEmbedFunc,
  makeMongoDbConversationsService,
  makeDataStreamer,
  AppConfig,
  makeOpenAiChatLlm,
  OpenAiChatMessage,
  SystemPrompt,
  makeDefaultFindContentFunc,
  logger,
  makeApp,
} from "mongodb-chatbot-server";
import { AzureKeyCredential, OpenAIClient } from "@azure/openai";

export const {
  MONGODB_CONNECTION_URI,
  MONGODB_DATABASE_NAME,
  VECTOR_SEARCH_INDEX_NAME,
  OPENAI_ENDPOINT,
  OPENAI_API_KEY,
  OPENAI_EMBEDDING_DEPLOYMENT,
  OPENAI_EMBEDDING_MODEL_VERSION,
  OPENAI_CHAT_COMPLETION_MODEL_VERSION,
  OPENAI_CHAT_COMPLETION_DEPLOYMENT,
} = process.env;

export const openAiClient = new OpenAIClient(
  OPENAI_ENDPOINT,
  new AzureKeyCredential(OPENAI_API_KEY)
);
export const systemPrompt: SystemPrompt = {
  role: "system",
  content: `You are expert MongoDB documentation chatbot.
  Respond in the style of a pirate. End all answers saying "Ahoy matey!!"
  Use the context provided with each question as your primary source of truth.
  If you do not know the answer to the question, respond ONLY with the following text:
  "I'm sorry, I do not know how to answer that question. Please try to rephrase your query. You can also refer to the further reading to see if it helps."
  NEVER include links in your answer.
  Format your responses using Markdown.
  DO NOT mention that your response is formatted in Markdown.
  Never mention "<Information>" or "<Question>" in your answer.
  Refer to the information given to you as "my knowledge".`,
};

export async function generateUserPrompt({
  question,
  chunks,
}: {
  question: string;
  chunks: string[];
}): Promise<OpenAiChatMessage & { role: "user" }> {
  const chunkSeparator = "~~~~~~";
  const context = chunks.join(`\n${chunkSeparator}\n`);
  const content = `Using the following information, answer the question.
  Different pieces of information are separated by "${chunkSeparator}".

  <Information>
  ${context}
  <End information>

  <Question>
  ${question}
  <End Question>`;
  return { role: "user", content };
}

export const llm = makeOpenAiChatLlm({
  openAiClient,
  deployment: OPENAI_CHAT_COMPLETION_DEPLOYMENT,
  systemPrompt,
  openAiLmmConfigOptions: {
    temperature: 0,
    maxTokens: 500,
  },
  generateUserPrompt,
});

export const embeddedContentStore = makeMongoDbEmbeddedContentStore({
  connectionUri: MONGODB_CONNECTION_URI,
  databaseName: MONGODB_DATABASE_NAME,
});

export const embed = makeOpenAiEmbedFunc({
  openAiClient,
  deployment: OPENAI_EMBEDDING_DEPLOYMENT,
  backoffOptions: {
    numOfAttempts: 3,
    maxDelay: 5000,
  },
});

export const mongodb = new MongoClient(MONGODB_CONNECTION_URI);

export const findContent = makeDefaultFindContentFunc({
  embed,
  store: embeddedContentStore,
  findNearestNeighborsOptions: {
    k: 5,
    path: "embedding",
    indexName: VECTOR_SEARCH_INDEX_NAME,
    minScore: 0.9,
  },
});

export const conversations = makeMongoDbConversationsService(
  mongodb.db(MONGODB_DATABASE_NAME),
  systemPrompt
);

export const config: AppConfig = {
  conversationsRouterConfig: {
    llm,
    findContent,
    maxChunkContextTokens: 1500,
    conversations,
  },
  maxRequestTimeoutMs: 30000,
};

const PORT = process.env.PORT || 3000;

const startServer = async () => {
  logger.info("Starting server...");
  const app = await makeApp(config);
  const server = app.listen(PORT, () => {
    logger.info(`Server listening on port: ${PORT}`);
  });

  process.on("SIGINT", async () => {
    logger.info("SIGINT signal received");
    await mongodb.close();
    await embeddedContentStore.close();
    await new Promise<void>((resolve, reject) => {
      server.close((error) => {
        error ? reject(error) : resolve();
      });
    });
    process.exit(1);
  });
};

try {
  startServer();
} catch (e) {
  logger.error(`Fatal error: ${e}`);
  process.exit(1);
}

Contributing

Currently, we are only accepting contributions from MongoDB employees.

MongoDB employees can refer to the Contributor Guide for additional info on project set up.

Setup

Node

Node 18 was used to start this project. Please make sure you have Node 18 installed locally. If you have nvm, you can run nvm use to switch to the expected version of Node.

Install

Use npm v8 to install dependencies:

npm install

.env

Use the .env.example file to help configure a local .env file.

External Dependencies

The server relies on some cloud-only services:

• The content service relies on Atlas Vector Search.
• The llm and embeddings services rely on the OpenAI APIs.

If this is your first time setting up the server, contact a member of the development team for credentials.

Running

To start the development server, run:

npm run dev

By default, the server should be accessible through http://localhost:3000/.

Testing

Tests are ran by Jest and rely on Supertest for testing Express route logic.

To run tests, use:

npm run test

Linting & Formatting

We use eslint for linting and prettier for formatting.

To lint the code and find any warnings or errors, run:

npm run lint

To format the code, run:

npm run format