runOnUIAsync

runOnUIAsync lets you asynchronously run workletized functions on the UI thread. It returns a Promise of the worklet's return value. The Promise is resolved asynchronously, not immediately after the callback execution.

To compare it with scheduleOnUI and runOnUISync, see Running worklets on the UI runtime.

Reference

import { runOnUIAsync } from 'react-native-worklets';

// RN Runtime, JS thread

const result: Promise<number> = runOnUIAsync((): number => {
  return 1;
});

await result; // 1

Type definitions

function runOnUIAsync<Args extends unknown[], ReturnValue>(
  worklet: (...args: Args) => ReturnValue,
  ...args: Args
): Promise<ReturnValue>;

Arguments

worklet

A reference to a function you want to execute on the UI thread. Arguments to your function have to be passed to the function returned from runOnUIAsync i.e. runOnUIAsync(setValue, 10);.

Remarks

• It's a common mistake to execute function inside of runOnUIAsync like this: runOnUIAsync(myWorklet(10)). Here, the correct usage would be runOnUIAsync(myWorklet, 10).

• The callback passed as the argument is automatically workletized and ready to be run on the UI thread.

Call table

Mode	RN Runtime	UI Runtime	Worker Runtime
Bundle Mode	✅	✅	✅
Legacy Eval Mode	✅	❌	❌

What does it mean?

Platform compatibility

Native	Web
✅	✅