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

# Promise

A value that will be available in the future.
Use `andThen` to register callbacks, or `await` inside `async` to
suspend until the value is ready.
Supports cancellation: call `cancel()` to abort pending work and
propagate cancellation to chained promises.

## Fields

### `andThen`

Register a callback for when the promise fulfills.
The handler may return a value that becomes the next promise's result.

## Constructors

### `new`

<div class="signature">
  ```lua theme={null}
  new(executor: (resolve:(value: T) ->(), reject:(error: any) ->(), onCancel:(hook:() ->()) ->()) ->()) -> Promise<T>
  ```
</div>

Create a new promise with an executor function.
The executor receives resolve, reject, and onCancel callbacks.

### `resolve`

<div class="signature">
  ```lua theme={null}
  resolve(value: T?) -> Promise<T>
  ```
</div>

Create an already-resolved promise. Resolves with nil if no value given.

### `reject`

<div class="signature">
  ```lua theme={null}
  reject(error: any?) -> Promise<T>
  ```
</div>

Create an already-rejected promise. Error can be any Lua value.
Rejects with "rejected" if no argument is provided.

### `all`

<div class="signature">
  ```lua theme={null}
  all(promises: {Promise<T>}) -> Promise<{T}>
  ```
</div>

Wait for all promises to resolve; rejects if any rejects.
On rejection, the remaining promises that nothing else waits on are
cancelled.

## Methods

### `catch`

<div class="signature">
  ```lua theme={null}
  catch(onRejected: (error: any) -> any) -> any
  ```
</div>

Register a callback for when the promise rejects.
Errors can be any Lua value (string, table, number, etc.).

### `finally`

<div class="signature">
  ```lua theme={null}
  finally(onFinally: () ->()) -> Promise<T>
  ```
</div>

Register a callback that runs whether the promise fulfills or rejects.

### `cancel`

<div class="signature">
  ```lua theme={null}
  cancel() -> Promise<T>
  ```
</div>

Cancel this promise. Fires the onCancel hook (if registered),
propagates cancellation down to chained promises, and propagates
up to the parent if all its consumers are cancelled.
No-op if the promise is already settled.

### `onCancel`

<div class="signature">
  ```lua theme={null}
  onCancel(hook: () ->()) -> Promise<T>
  ```
</div>

Register a cancellation hook that fires when cancel() is called.
Used to clean up in-flight work (e.g. abort a network request).
Replaces any hook registered before.

### `getStatus`

<div class="signature">
  ```lua theme={null}
  getStatus() -> string
  ```
</div>

Returns the current state: "Pending", "Fulfilled", "Rejected", or "Cancelled".