> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/nuxt/nuxt/llms.txt
> Use this file to discover all available pages before exploring further.

# server/

> The server/ directory is used to register API and server handlers to your application.

Nuxt automatically scans files inside these directories to register API and server handlers with Hot Module Replacement (HMR) support.

```bash theme={null}
server/
  api/
    hello.ts      # /api/hello
  routes/
    bonjour.ts    # /bonjour
  middleware/
    log.ts        # log all requests
```

Each file should export a default function defined with `defineEventHandler()` or `eventHandler()` (alias).

The handler can directly return JSON data, a `Promise`, or use `event.node.res.end()` to send a response.

```ts server/api/hello.ts theme={null}
export default defineEventHandler((event) => {
  return {
    hello: 'world',
  }
})
```

You can now universally call this API in your pages and components:

```vue app/pages/index.vue theme={null}
<script setup lang="ts">
const { data } = await useFetch('/api/hello')
</script>

<template>
  <pre>{{ data }}</pre>
</template>
```

## Server Routes

Files inside the `~~/server/api` are automatically prefixed with `/api` in their route.

To add server routes without `/api` prefix, put them into `~~/server/routes` directory.

**Example:**

```ts server/routes/hello.ts theme={null}
export default defineEventHandler(() => 'Hello World!')
```

Given the example above, the `/hello` route will be accessible at `http://localhost:3000/hello`.

<Note>
  Note that currently server routes do not support the full functionality of dynamic routes as [pages](/directory-structure/pages#dynamic-routes) do.
</Note>

## Server Middleware

Nuxt will automatically read in any file in the `~~/server/middleware` to create server middleware for your project.

Middleware handlers will run on every request before any other server route to add or check headers, log requests, or extend the event's request object.

<Note>
  Middleware handlers should not return anything (nor close or respond to the request) and only inspect or extend the request context or throw an error.
</Note>

**Examples:**

```ts server/middleware/log.ts theme={null}
export default defineEventHandler((event) => {
  console.log('New request: ' + getRequestURL(event))
})
```

```ts server/middleware/auth.ts theme={null}
export default defineEventHandler((event) => {
  event.context.auth = { user: 123 }
})
```

## Server Plugins

Nuxt will automatically read any files in the `~~/server/plugins` directory and register them as Nitro plugins. This allows extending Nitro's runtime behavior and hooking into lifecycle events.

**Example:**

```ts server/plugins/nitroPlugin.ts theme={null}
export default defineNitroPlugin((nitroApp) => {
  console.log('Nitro plugin', nitroApp)
})
```

## Server Utilities

Server routes are powered by [h3js/h3](https://github.com/h3js/h3) which comes with a handy set of helpers.

You can add more helpers yourself inside the `~~/server/utils` directory.

For example, you can define a custom handler utility that wraps the original handler and performs additional operations before returning the final response.

**Example:**

```ts server/utils/handler.ts theme={null}
export const defineWrappedResponseHandler = <T extends EventHandlerRequest, D> (
  handler: EventHandler<T, D>,
): EventHandler<T, D> =>
  defineEventHandler<T>(async (event) => {
    try {
      // do something before the route handler
      const response = await handler(event)
      // do something after the route handler
      return { response }
    } catch (err) {
      // Error handling
      return { err }
    }
  })
```

## Recipes

### Route Parameters

Server routes can use dynamic parameters within brackets in the file name like `/api/hello/[name].ts` and be accessed via `event.context.params`.

```ts server/api/hello/[name].ts theme={null}
export default defineEventHandler((event) => {
  const name = getRouterParam(event, 'name')

  return `Hello, ${name}!`
})
```

You can now universally call this API on `/api/hello/nuxt` and get `Hello, nuxt!`.

### Matching HTTP Method

Handle file names can be suffixed with `.get`, `.post`, `.put`, `.delete`, ... to match request's [HTTP Method](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Methods).

```ts server/api/test.get.ts theme={null}
export default defineEventHandler(() => 'Test get handler')
```

```ts server/api/test.post.ts theme={null}
export default defineEventHandler(() => 'Test post handler')
```

Given the example above, fetching `/test` with:

* **GET** method: Returns `Test get handler`
* **POST** method: Returns `Test post handler`
* Any other method: Returns 405 error

### Catch-all Route

Catch-all routes are helpful for fallback route handling.

For example, creating a file named `~~/server/api/foo/[...].ts` will register a catch-all route for all requests that do not match any route handler, such as `/api/foo/bar/baz`.

```ts server/api/foo/[...].ts theme={null}
export default defineEventHandler((event) => {
  // event.context.path to get the route path: '/api/foo/bar/baz'
  // event.context.params._ to get the route segment: 'bar/baz'
  return `Default foo handler`
})
```

### Body Handling

```ts server/api/submit.post.ts theme={null}
export default defineEventHandler(async (event) => {
  const body = await readBody(event)
  return { body }
})
```

You can now universally call this API using:

```vue app/app.vue theme={null}
<script setup lang="ts">
async function submit () {
  const { body } = await $fetch('/api/submit', {
    method: 'post',
    body: { test: 123 },
  })
}
</script>
```

<Note>
  We are using `submit.post.ts` in the filename only to match requests with `POST` method that can accept the request body. When using `readBody` within a GET request, `readBody` will throw a `405 Method Not Allowed` HTTP error.
</Note>

### Query Parameters

Sample query `/api/query?foo=bar&baz=qux`

```ts server/api/query.get.ts theme={null}
export default defineEventHandler((event) => {
  const query = getQuery(event)

  return { a: query.foo, b: query.baz }
})
```

### Error Handling

If no errors are thrown, a status code of `200 OK` will be returned.

Any uncaught errors will return a `500 Internal Server Error` HTTP Error.

To return other error codes, throw an exception with `createError`:

```ts server/api/validation/[id].ts theme={null}
export default defineEventHandler((event) => {
  const id = Number.parseInt(event.context.params.id) as number

  if (!Number.isInteger(id)) {
    throw createError({
      status: 400,
      statusText: 'ID should be an integer',
    })
  }
  return 'All good'
})
```

### Runtime Config

```ts server/api/foo.ts theme={null}
export default defineEventHandler(async (event) => {
  const config = useRuntimeConfig(event)

  const repo = await $fetch('https://api.github.com/repos/nuxt/nuxt', {
    headers: {
      Authorization: `token ${config.githubToken}`,
    },
  })

  return repo
})
```

<Note>
  Giving the `event` as argument to `useRuntimeConfig` is optional, but it is recommended to pass it to get the runtime config overwritten by [environment variables](/advanced/runtime-config#environment-variables) at runtime for server routes.
</Note>

### Request Cookies

```ts server/api/cookies.ts theme={null}
export default defineEventHandler((event) => {
  const cookies = parseCookies(event)

  return { cookies }
})
```