API Routes in Next.js

API Routes in Next.js allow you to build backend APIs directly inside your Next.js application. You can handle requests, connect to databases, and perform server-side logic without setting up a separate backend server.

1. What are API Routes?

API Routes are server-side functions that respond to HTTP requests such as GET, POST, PUT, DELETE.
They run only on the server and are not included in the client-side bundle.

2. API Routes in App Router (Recommended)

In the App Router, API routes are created using route.js inside the app/api directory.

Folder Structure

app/
└── api/
    └── posts/
        └── route.js

3. Basic API Route Example

GET Request

export async function GET() {
  return new Response(
    JSON.stringify({ message: 'Hello from API' }),
    { status: 200 }
  );
}

Access URL:

/api/posts

4. Handling Different HTTP Methods

export async function GET() {
  return Response.json({ posts: [] });
}

export async function POST(request) {
  const body = await request.json();
  return Response.json({ success: true, body });
}

Supported methods:

• GET

• POST

• PUT

• PATCH

• DELETE

5. Request Parameters

Query Parameters

/api/posts?id=1

export async function GET(request) {
  const { searchParams } = new URL(request.url);
  const id = searchParams.get('id');
  return Response.json({ id });
}

Dynamic API Routes

app/
└── api/
    └── posts/
        └── [id]/
            └── route.js

export async function GET(request, { params }) {
  return Response.json({ postId: params.id });
}

6. Connecting to a Database (Example)

import { connectDB } from '@/lib/db';

export async function GET() {
  const posts = await connectDB().find();
  return Response.json(posts);
}

7. API Routes in Pages Router (Older)

pages/
└── api/
    └── users.js

export default function handler(req, res) {
  res.status(200).json({ message: 'Hello API' });
}

8. Security and Best Practices

• Use environment variables (.env.local)

• Validate request data

• Handle errors properly

• Do not expose sensitive logic to the client

Use Cases

• Authentication

• CRUD operations

• Form handling

• Database interactions

• Third-party API integration

Conclusion

API Routes make Next.js a full-stack framework, allowing you to build both frontend and backend in a single project. Using the App Router, you can create clean, scalable, and secure APIs with minimal setup.