How to Build an AI Chatbot with Node.js

This tutorial builds a simple conversational chatbot in Node.js using the open-source Violet library. If you want the theory first, read how conversational AI works; otherwise, let's build.

Step 1 — Set up the project

Create a project and install the conversation library:

$ mkdir my-bot && cd my-bot
$ npm init -y
$ npm install violet-conversations --save

Step 2 — Define your intents

Create index.js and register what the bot should respond to. Each respondTo block lists the phrases you expect and how to reply:

var violet = require('violet').script();

violet.respondTo({
  expecting: ['Hello', 'Hi there'],
  resolve: (response) => {
    response.say('Hi! What can I help you with?');
  }
});

Step 3 — Add application logic

Inside a resolve handler you can call any of your own code — a database, an API, an LLM — and then reply. Here we branch on a captured value:

violet.respondTo({
  expecting: ['What is the weather in [[city]]'],
  resolve: async (response) => {
    const city = response.get('city');
    const temp = await getWeather(city);
    response.say(`It is ${temp}° in ${city}.`);
  }
});

Step 4 — Test locally

Rather than deploying on every change, run the browser-based test harness and type messages to your bot directly. Iterate until the conversation flows the way you want.

Step 5 — Deploy

Deploy your app to a server or serverless function, then connect it to Alexa or Google Assistant using their developer consoles. See the Violet documentation for platform-specific setup.

Where this goes next

Add an LLM in the resolve step and a memory store, and you have the core of a modern AI companion. That's exactly the architecture behind the AI girlfriend apps we break down here.

Continue: How AI Girlfriend Apps Work → · Back to the AI Companions Guide