Welcome! 👋
In this tutorial, we’ll build a modular, production-ready Node.js backend for IdeaLens — an AI assistant that helps creators brainstorm, summarize, caption, and ideate content. We’ll also integrate Groq to access blazing-fast LLMs like LLaMA 3.

📦 Prerequisites

Make sure you have the following:

  • Node.js (v16+)
  • npm or yarn
  • MongoDB Atlas or local
  • A Groq API Key
  • REST client (Postman, Thunder Client, etc.)

📁 Folder Structure 

backend/
├── controllers/
│   └── summary.controller.js
├── routes/
│   └── summary.route.js
├── utils/
│   └── groqClient.js  <-- ✨ Groq integration
├── app.js
├── server.js
└── .env

📦 Install Dependencies 

npm install express cors cookie-parser dotenv mongoose axios

We’ll use axios to call the Groq API.

🧠 Integrating Groq: Ultra-fast Open-Source LLMs

Create utils/groqClient.js:

const axios = require("axios");

const GROQ_API_KEY = process.env.GROQ_API_KEY;

const groq = axios.create({
  baseURL: "https://api.groq.com/openai/v1/chat/completions",
  headers: {
    "Authorization": `Bearer ${GROQ_API_KEY}`,
    "Content-Type": "application/json"
  }
});

async function chatWithGroq(messages, model = "llama-3.3-70b-versatile") {
  try {
    const response = await groq.post("/chat/completions", {
      model,
      messages,
      temperature: 0.7
    });

    return response.data.choices[0].message.content;
  } catch (err) {
    console.error("Groq Error:", err.response?.data || err.message);
    throw new Error("Groq API failed");
  }
}

module.exports = { chatWithGroq };

You can now easily switch between llama-3.3-70b-versatileor others.

🔁 Using Groq in a Controller

In controllers/summary.controller.js:

const { chatWithGroq } = require("../utils/groqClient");

const generateSummary = async (req, res) => {
  const { idea } = req.body;

  const messages = [
    {
      role: "system",
      content: "You're a creative assistant helping generate content ideas."
    },
    {
      role: "user",
      content: `Summarize the following content idea: "${idea}". Include mood, genre, platform suggestions, hooks, and short video direction.`
    }
  ];

  try {
    const aiResponse = await chatWithGroq(messages);
    res.json({ summary: aiResponse });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
};

module.exports = { generateSummary };

📌 Example Route: /api/summary

In routes/summary.route.js:

const express = require("express");
const router = express.Router();
const { generateSummary } = require("../controllers/summary.controller");

router.post("/", generateSummary);

module.exports = router;

🔐 Environment Variables

In .env:

PORT=5000
CLIENT_URL=http://localhost:3000
MONGO_URI=your_mongo_url
GROQ_API_KEY=your_groq_api_key

🛠️ Bootstrapping the App

In app.js:

const express = require("express");
const cors = require("cors");
const cookieParser = require("cookie-parser");
const summaryRoutes = require("./routes/summary.route");

const app = express();

app.use(cors({ origin: process.env.CLIENT_URL, credentials: true }));
app.use(express.json());
app.use(cookieParser());

app.use("/api/summary", summaryRoutes);

app.get("/", (req, res) => {
  res.send("IdeaLens backend is up 🚀");
});

module.exports = app;

In server.js:

const app = require("./app");
const mongoose = require("mongoose");
require("dotenv").config();

const PORT = process.env.PORT || 5000;

mongoose.connect(process.env.MONGO_URI)
  .then(() => {
    app.listen(PORT, () =>
      console.log(`Server running at http://localhost:${PORT}`)
    );
  })
  .catch((err) => console.error("MongoDB connection failed", err));

📌 Route Overview

Endpoint Method Description
/api/summary POST Generate structured summary with Groq
/api/analyze POST Content analysis
/api/captions POST Generate captions + hashtags
/api/songs POST Suggest music tracks
/api/chat POST General AI chat
/api/refine POST Refine based on user feedback
/api/upload-media POST Upload audio/video for analysis
/api/auth POST Auth with JWT & cookies

All powered by modular routes and AI controller functions.

🎯 Done! Your Groq-Powered Node.js Backend🚀

You’ve now got a fully working Express backend with Groq integrated — giving you high-performance LLM workflows for idea summarization, creative chatting, and content generation in your IdeaLens platform.