> ## Documentation Index
> Fetch the complete documentation index at: https://www.canva.dev/docs/apps/llms.txt
> Use this file to discover all available pages before exploring further.

# appProcess.current.setOnDispose

API reference for the appProcess.current.setOnDispose method.

Registers a callback that runs when the current app process is about to close.

* Apps can't register multiple callbacks.
* If an app attempts to register multiple callbacks, only the last callback will be registered.
* The app process will remain open until the callback resolves or a timeout error occurs.
* The complete execution of the callback is not guaranteed as some user actions (e.g. closing tabs) may close the process prematurely.

## Usage: Handle process cleanup

```typescript
import { appProcess } from '@canva/platform';

const cleanupDisposer = appProcess.current.setOnDispose(async (params) => {
  if (params.reason === 'completed') {
    await saveChanges();
  }
});

// Later: cleanup the listener
await cleanupDisposer();
```

## Parameters

<Prop.List>
  <Prop name="callback" required type="OnDisposeCallback<T>" sourceLineNumbers={[369]}>
    The callback to run when the current app process is about to close.

    **Parameters**

    <Prop.List>
      <Prop name="opts" required type="T" sourceLineNumbers={[507]}>
        Parameters passed to the `setOnDispose` callback when a process is about to close.

        <PillAccordion defaultExpanded={false} title={<>Properties of <strong>opts</strong></>}>
          <Prop.List>
            <Prop name="reason" required type="CloseReason" sourceLineNumbers={[231]}>
              The reason the app process is closing.

              <Prop.Extras>
                **Available values**:

                * `"completed"`
                * `"aborted"`
              </Prop.Extras>
            </Prop>
          </Prop.List>
        </PillAccordion>
      </Prop>
    </Prop.List>

    **Returns**

    `Promise<void>`
  </Prop>
</Prop.List>

## Returns

A disposer function that cleans up the registered callback.

() => `Promise<void>`