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
.
For example, the following API route pages/api/user.js
handles a json
response:
export default (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 as default a function (a.k.a request handler), which then receives the following parameters:
req
: An instance of http.IncomingMessage, plus some pre-built middlewares you can see hereres
: An instance of http.ServerResponse, plus some helper functions you can see hereTo handle different HTTP methods in an API route, you can use req.method
in your request handler, like so:
export default (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.
API Routes do not specify CORS headers, meaning they are same-origin only by default. You can customize such behavior by wrapping the request handler with the cors middleware.
API Routes do not increase your client-side bundle size. They are server-side only bundles.
For more information on what to do next, we recommend the following sections: