exnexus 🚀

exnexus is a lightweight, production-ready utility belt for Node.js Express applications. It provides the core backend essentials every API needs: centralized error handling, structured responses, request logging, semantic error creators, and optional MongoDB connection helpers.

✨ Features

• asyncHandler: Eliminate repetitive try/catch blocks in async controllers.
• responseEnhancer: Add expressive helpers like res.success(), res.created(), res.fail(), and more.
• errors Utility: Create semantic HTTP errors like errors.notFound() or errors.badRequest().
• requestLogger: Log HTTP requests with method, URL, status, and response duration.
• ApiError & ApiResponse: Standardized JSON contracts for errors and successful responses.
• errorHandler: Global middleware for formatting and handling errors consistently.
• connectDB: Optional MongoDB connection helper for Mongoose users.

📦 Installation

Core package

npm install exnexus

With MongoDB support

npm install exnexus mongoose

mongoose is an optional peer dependency and is only needed if you use connectDB().

⚡ Quick Start

1. Initialize Global Middleware

import express from "express";
import { responseEnhancer, requestLogger, errorHandler } from "exnexus";

const app = express();

app.use(express.json());
app.use(requestLogger);
app.use(responseEnhancer);

// ... your routes ...

app.use(errorHandler);

2. Write Clean Controllers

import { asyncHandler, errors } from "exnexus";

export const getProfile = asyncHandler(async (req, res) => {
  const user = await User.findById(req.user._id);

  if (!user) {
    throw errors.notFound("User not found");
  }

  return res.success(user, "Profile retrieved successfully");
});

3. Optional MongoDB Connection

import express from "express";
import {
  connectDB,
  responseEnhancer,
  requestLogger,
  errorHandler,
} from "exnexus";

const app = express();

await connectDB({
  uri: process.env.MONGO_URI,
  retries: 3,
  retryDelay: 3000,
});

app.use(express.json());
app.use(requestLogger);
app.use(responseEnhancer);

// ... routes ...

app.use(errorHandler);

app.listen(5000, () => {
  console.log("Server running on port 5000");
});

🧩 Response Helpers

res.success(data, "Fetched successfully");
res.created(data, "Created successfully");
res.fail("Something went wrong");

Example:

{
  "success": true,
  "message": "Fetched successfully",
  "data": {
    "id": 1
  }
}

❌ Error Handling Example

import { asyncHandler, errors } from "exnexus";

export const getUser = asyncHandler(async (req, res) => {
  const user = await User.findById(req.params.id);

  if (!user) {
    throw errors.notFound("User not found");
  }

  return res.success(user);
});

🛢️ MongoDB Helper

import { connectDB } from "exnexus";

await connectDB({
  uri: process.env.MONGO_URI,
  retries: 3,
  retryDelay: 5000,
  exitOnFailure: true,
});

Options

| Option | Type | Default | Description | | ---------------- | -------- | --------------------- | --------------------------- | | uri | string | process.env.MONGO_URI | MongoDB connection string | | options | object | {} | Mongoose connection options | | retries | number | 3 | Retry attempts | | retryDelay | number | 5000 | Delay between retries | | exitOnFailure | boolean | true | Exit process on failure | | logger | object | console | Logger instance | | onConnected | function | - | Callback on connect | | onError | function | - | Callback on error | | onDisconnected | function | - | Callback on disconnect |

📂 Project Structure

src/
├── db/
├── middlewares/
├── utils/
└── index.js

⚙️ Environment Variables

| Variable | Description | Default | | --------- | ------------------------ | ---------- | | NODE_ENV | Show stack traces in dev | production | | LOG_LEVEL | Logging level | info | | MONGO_URI | Mongo connection string | - |

🧪 Testing

npm test

🤝 Contributing

PRs, issues, and ideas are welcome.

GitHub: https://github.com/FenilP07/Express-Toolkit

💬 Support

Open an issue for help or questions.

📄 License

MIT License