---
description: Next.js supports API Routes, which allow you to build your API without leaving your Next.js app. Learn how it works here.
---
# API Routes
Examples
API routes provide a straightforward solution to build your **API** with Next.js.
Any file inside the folder `pages/api` is mapped to `/api/*` and will be treated as an API endpoint instead of a `page`. They are server-side only bundles and won't increase your client-side bundle size.
For example, the following API route `pages/api/user.js` handles a `json` response:
```js
export default function handler(req, res) {
res.statusCode = 200
res.setHeader('Content-Type', 'application/json')
res.end(JSON.stringify({ name: 'John Doe' }))
}
```
For an API route to work, you need to export a function as default (a.k.a **request handler**), which then receives the following parameters:
- `req`: An instance of [http.IncomingMessage](https://nodejs.org/api/http.html#http_class_http_incomingmessage), plus some pre-built middlewares you can see [here](/docs/api-routes/api-middlewares.md)
- `res`: An instance of [http.ServerResponse](https://nodejs.org/api/http.html#http_class_http_serverresponse), plus some helper functions you can see [here](/docs/api-routes/response-helpers.md)
To handle different HTTP methods in an API route, you can use `req.method` in your request handler, like so:
```js
export default function handler(req, res) {
if (req.method === 'POST') {
// Process a POST request
} else {
// Handle any other HTTP method
}
}
```
To fetch API endpoints, take a look into any of the examples at the start of this section.
## Caveats
- API Routes [do not specify CORS headers](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS), meaning they are **same-origin only** by default. You can customize such behavior by wrapping the request handler with the [cors middleware](/docs/api-routes/api-middlewares.md#connectexpress-middleware-support).
- API Routes can't be used with [`next export`](/docs/advanced-features/static-html-export.md)
## Related
For more information on what to do next, we recommend the following sections: