| --- |
| title: unstable_rethrow |
| description: API Reference for the unstable_rethrow function. |
| version: unstable |
| --- |
|
|
| `unstable_rethrow` can be used to avoid catching internal errors thrown by Next.js when attempting to handle errors thrown in your application code. |
|
|
| For example, calling the `notFound` function will throw an internal Next.js error and render the [`not-found.js`](/docs/app/api-reference/file-conventions/not-found) component. However, if used inside the `try` block of a `try/catch` statement, the error will be caught, preventing `not-found.js` from rendering: |
|
|
| ```tsx filename="@/app/ui/component.tsx" |
| import { notFound } from 'next/navigation' |
| |
| export default async function Page() { |
| try { |
| const post = await fetch('https://.../posts/1').then((res) => { |
| if (res.status === 404) notFound() |
| if (!res.ok) throw new Error(res.statusText) |
| return res.json() |
| }) |
| } catch (err) { |
| console.error(err) |
| } |
| } |
| ``` |
|
|
| You can use `unstable_rethrow` API to re-throw the internal error and continue with the expected behavior: |
|
|
| ```tsx filename="@/app/ui/component.tsx" |
| import { notFound, unstable_rethrow } from 'next/navigation' |
| |
| export default async function Page() { |
| try { |
| const post = await fetch('https://.../posts/1').then((res) => { |
| if (res.status === 404) notFound() |
| if (!res.ok) throw new Error(res.statusText) |
| return res.json() |
| }) |
| } catch (err) { |
| unstable_rethrow(err) |
| console.error(err) |
| } |
| } |
| ``` |
|
|
| The following Next.js APIs rely on throwing an error which should be rethrown and handled by Next.js itself: |
|
|
| - [`notFound()`](/docs/app/api-reference/functions/not-found) |
| - [`redirect()`](/docs/app/guides/redirecting |
| - [`permanentRedirect()`](/docs/app/guides/redirecting |
|
|
| If a route segment is marked to throw an error unless it's static, a Dynamic API call will also throw an error that should similarly not be caught by the developer. Note that Partial Prerendering (PPR) affects this behavior as well. These APIs are: |
| |
| - [`cookies`](/docs/app/api-reference/functions/cookies) |
| - [`headers`](/docs/app/api-reference/functions/headers) |
| - [`searchParams`](/docs/app/api-reference/file-conventions/page#searchparams-optional) |
| - `fetch(..., { cache: 'no-store' })` |
| - `fetch(..., { next: { revalidate: 0 } })` |
| |
| > **Good to know**: |
| > |
| > - This method should be called at the top of the catch block, passing the error object as its only argument. It can also be used within a `.catch` handler of a promise. |
| > - You may be able to avoid using `unstable_rethrow` if you encapsulate your API calls that throw and let the **caller** handle the exception. |
| > - Only use `unstable_rethrow` if your caught exceptions may include both application errors and framework-controlled exceptions (like `redirect()` or `notFound()`). |
| > - Any resource cleanup (like clearing intervals, timers, etc) would have to either happen prior to the call to `unstable_rethrow` or within a `finally` block. |
| |
