Middleware functions run before route handlers on every request. They can modify the request, add context, or return early responses.

Create files in server/middleware/. They run in alphabetical order:

import { defineMiddleware } from "nitro";

export default defineMiddleware((event) => {
  event.context.auth = { name: "User " + Math.round(Math.random() * 100) };
});

Middleware can:

• Add data to event.context for use in handlers
• Return a response early to short-circuit the request
• Modify request headers or other properties

Data added to event.context in middleware is available in all subsequent handlers:

import { defineHandler } from "nitro";

export default defineHandler((event) => ({
  auth: event.context.auth,
}));