# Get Flow Control Key

> Get details of a specific Flow Control key.

## Endpoint

`GET https://qstash-{region}.upstash.io/v2/keys/rotate`

Get details of a specific Flow Control key.

Flow Control keys are used to manage concurrency and rate limiting for workflow steps.
This endpoint returns the current waitlist size for the specified flow control key,
which indicates how many workflow steps are currently waiting due to flow control constraints.


## Parameters

- `flowControlKey` (path, string, required): The Flow Control key to retrieve.

## Responses

### 200 - Flow control key details

- `flowControlKey` (string): The flow control key name
- `waitlistSize` (integer): The number of messages waiting due to flow control configuration.

### 400 - Bad Request

- `error` (string, required): Error message

### 401 - Unauthorized

- `error` (string, required): Error message

### 404 - Flow Control key not found

- `error` (string, required): Error message

### 500 - Internal Server Error

- `error` (string, required): Error message

## cURL

```bash
curl --request GET \
  --url https://qstash-{region}.upstash.io/v2/keys/rotate \
  --header 'Authorization: Bearer <token>'
```