next.js/docs/01-app/03-api-reference/04-functions/after.mdx

---
title: after
description: API Reference for the after function.
---

`after` allows you to schedule work to be executed after a response (or prerender) is finished. This is useful for tasks and other side effects that should not block the response, such as logging and analytics.

It can be used in [Server Components](/docs/app/getting-started/server-and-client-components) (including [`generateMetadata`](https://nextjs.org/docs/app/api-reference/functions/generate-metadata)), [Server Actions](/docs/app/getting-started/updating-data), [Route Handlers](/docs/app/api-reference/file-conventions/route), and [Middleware](/docs/app/api-reference/file-conventions/middleware).

The function accepts a callback that will be executed after the response (or prerender) is finished:

```tsx filename="app/layout.tsx" switcher
import { after } from 'next/server'
// Custom logging function
import { log } from '@/app/utils'

export default function Layout({ children }: { children: React.ReactNode }) {
  after(() => {
    // Execute after the layout is rendered and sent to the user
    log()
  })
  return <>{children}</>
}
```

```jsx filename="app/layout.jsx" switcher
import { after } from 'next/server'
// Custom logging function
import { log } from '@/app/utils'

export default function Layout({ children }) {
  after(() => {
    // Execute after the layout is rendered and sent to the user
    log()
  })
  return <>{children}</>
}
```

> **Good to know:** `after` is not a [Dynamic API](/docs/app/getting-started/partial-prerendering#dynamic-rendering) and calling it does not cause a route to become dynamic. If it's used within a static page, the callback will execute at build time, or whenever a page is revalidated.

## Reference

### Parameters

- A callback function which will be executed after the response (or prerender) is finished.

### Duration

`after` will run for the platform's default or configured max duration of your route. If your platform supports it, you can configure the timeout limit using the [`maxDuration`](/docs/app/api-reference/file-conventions/route-segment-config#maxduration) route segment config.

## Good to know

- `after` will be executed even if the response didn't complete successfully. Including when an error is thrown or when `notFound` or `redirect` is called.
- You can use React `cache` to deduplicate functions called inside `after`.
- `after` can be nested inside other `after` calls, for example, you can create utility functions that wrap `after` calls to add additional functionality.

## Examples

### With request APIs

You can use request APIs such as [`cookies`](/docs/app/api-reference/functions/cookies) and [`headers`](/docs/app/api-reference/functions/headers) inside `after` in [Server Actions](/docs/app/getting-started/updating-data) and [Route Handlers](/docs/app/api-reference/file-conventions/route). This is useful for logging activity after a mutation. For example:

```ts filename="app/api/route.ts" highlight={2,7-9} switcher
import { after } from 'next/server'
import { cookies, headers } from 'next/headers'
import { logUserAction } from '@/app/utils'

export async function POST(request: Request) {
  // Perform mutation
  // ...

  // Log user activity for analytics
  after(async () => {
    const userAgent = (await headers().get('user-agent')) || 'unknown'
    const sessionCookie =
      (await cookies().get('session-id'))?.value || 'anonymous'

    logUserAction({ sessionCookie, userAgent })
  })

  return new Response(JSON.stringify({ status: 'success' }), {
    status: 200,
    headers: { 'Content-Type': 'application/json' },
  })
}
```

```js filename="app/api/route.js" highlight={2,7-9} switcher
import { after } from 'next/server'
import { cookies, headers } from 'next/headers'
import { logUserAction } from '@/app/utils'

export async function POST(request) {
  // Perform mutation
  // ...

  // Log user activity for analytics
  after(async () => {
    const userAgent = (await headers().get('user-agent')) || 'unknown'
    const sessionCookie =
      (await cookies().get('session-id'))?.value || 'anonymous'

    logUserAction({ sessionCookie, userAgent })
  })

  return new Response(JSON.stringify({ status: 'success' }), {
    status: 200,
    headers: { 'Content-Type': 'application/json' },
  })
}
```

However, you cannot use these request APIs inside `after` in [Server Components](/docs/app/getting-started/server-and-client-components). This is because Next.js needs to know which part of the tree access the request APIs to support [Partial Prerendering](/docs/app/getting-started/partial-prerendering), but `after` runs after React's rendering lifecycle.

## Platform Support

| Deployment Option                                                   | Supported         |
| ------------------------------------------------------------------- | ----------------- |
| [Node.js server](/docs/app/getting-started/deploying#nodejs-server) | Yes               |
| [Docker container](/docs/app/getting-started/deploying#docker)      | Yes               |
| [Static export](/docs/app/getting-started/deploying#static-export)  | No                |
| [Adapters](/docs/app/getting-started/deploying#adapters)            | Platform-specific |

Learn how to [configure `after`](/docs/app/guides/self-hosting#after) when self-hosting Next.js.

<details id="after-serverless">
  <summary>Reference: supporting `after` for serverless platforms</summary>

Using `after` in a serverless context requires waiting for asynchronous tasks to finish after the response has been sent. In Next.js and Vercel, this is achieved using a primitive called `waitUntil(promise)`, which extends the lifetime of a serverless invocation until all promises passed to [`waitUntil`](https://vercel.com/docs/functions/functions-api-reference#waituntil) have settled.

If you want your users to be able to run `after`, you will have to provide your implementation of `waitUntil` that behaves in an analogous way.

When `after` is called, Next.js will access `waitUntil` like this:

```jsx
const RequestContext = globalThis[Symbol.for('@next/request-context')]
const contextValue = RequestContext?.get()
const waitUntil = contextValue?.waitUntil
```

Which means that `globalThis[Symbol.for('@next/request-context')]` is expected to contain an object like this:

```tsx
type NextRequestContext = {
  get(): NextRequestContextValue | undefined
}

type NextRequestContextValue = {
  waitUntil?: (promise: Promise<any>) => void
}
```

Here is an example of the implementation.

```tsx
import { AsyncLocalStorage } from 'node:async_hooks'

const RequestContextStorage = new AsyncLocalStorage<NextRequestContextValue>()

// Define and inject the accessor that next.js will use
const RequestContext: NextRequestContext = {
  get() {
    return RequestContextStorage.getStore()
  },
}
globalThis[Symbol.for('@next/request-context')] = RequestContext

const handler = (req, res) => {
  const contextValue = { waitUntil: YOUR_WAITUNTIL }
  // Provide the value
  return RequestContextStorage.run(contextValue, () => nextJsHandler(req, res))
}
```

</details>

## Version History

| Version History | Description                  |
| --------------- | ---------------------------- |
| `v15.1.0`       | `after` became stable.       |
| `v15.0.0-rc`    | `unstable_after` introduced. |