# useAsyncRateLimitedCallback

# Function: useAsyncRateLimitedCallback()

```ts
function useAsyncRateLimitedCallback<TFn>(fn, options): (...args) => Promise<ReturnType<TFn>>;
```

Defined in: [react-pacer/src/async-rate-limiter/useAsyncRateLimitedCallback.ts:59](https://github.com/TanStack/pacer/blob/main/packages/react-pacer/src/async-rate-limiter/useAsyncRateLimitedCallback.ts#L59)

A React hook that creates a rate-limited version of an async callback function.
This hook is a convenient wrapper around the `useAsyncRateLimiter` hook,
providing a stable, async rate-limited function reference for use in React components.

Async rate limiting is a "hard limit" approach for async functions: it allows all calls
until the limit is reached, then blocks (rejects) subsequent calls until the window resets.
Unlike throttling or debouncing, it does not attempt to space out or collapse calls.
This can lead to bursts of rapid executions followed by periods where all calls are blocked.

The async rate limiter supports two types of windows:
- 'fixed': A strict window that resets after the window period. All executions within the window count
  towards the limit, and the window resets completely after the period.
- 'sliding': A rolling window that allows executions as old ones expire. This provides a more
  consistent rate of execution over time.

For smoother execution patterns, consider:
- useAsyncThrottledCallback: When you want consistent spacing between executions (e.g. UI updates)
- useAsyncDebouncedCallback: When you want to collapse rapid calls into a single execution (e.g. search input)

Async rate limiting should primarily be used when you need to enforce strict limits
on async operations, like API rate limits or other scenarios requiring hard caps
on execution frequency.

This hook provides a simpler API compared to `useAsyncRateLimiter`, making it ideal for basic
async rate limiting needs. However, it does not expose the underlying AsyncRateLimiter instance.

For advanced usage requiring features like:
- Manual cancellation
- Access to execution counts
- Custom useCallback dependencies

Consider using the `useAsyncRateLimiter` hook instead.

## Type Parameters

### TFn

`TFn` *extends* `AnyAsyncFunction`

## Parameters

### fn

`TFn`

### options

[`ReactAsyncRateLimiterOptions`](../interfaces/ReactAsyncRateLimiterOptions.md)\<`TFn`, \{
\}\>

## Returns

```ts
(...args): Promise<ReturnType<TFn>>;
```

### Parameters

#### args

...`Parameters`\<`TFn`\>

### Returns

`Promise`\<`ReturnType`\<`TFn`\>\>

## Example

```tsx
// Rate limit async API calls to maximum 5 calls per minute with a sliding window
const makeApiCall = useAsyncRateLimitedCallback(
  async (data: ApiData) => {
    return fetch('/api/endpoint', { method: 'POST', body: JSON.stringify(data) });
  },
  {
    limit: 5,
    window: 60000, // 1 minute
    windowType: 'sliding',
    onReject: () => {
      console.warn('API rate limit reached. Please wait before trying again.');
    }
  }
);
```