runOnUIAsync

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

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

Reference

Code

Code

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1function compute() {

2 'worklet';

3 return 1;

4}

5

6const pending = runOnUIAsync(compute);

7console.log('The RN Runtime continues while the result is pending');

8const result = await pending;

9console.log(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 after the function 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
✅	✅