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

# Start Application

> Start your application.

<ParamField header="Authorization" type="string" placeholder="API Key" required>
  The API key for your account. You can find this in your [account settings](https://squarecloud.app/en/account/security).
</ParamField>

Starts a stopped application on its assigned cluster. It is a no-op if the application is already running, so it is safe to call as part of a script without first checking [Get Application Status](/en/api-reference/endpoint/apps/status).

Starting only brings the existing files and configuration online, it does not deploy new code; use [Upload Application](/en/api-reference/endpoint/apps/upload) for a first deployment or [Commit Application](/en/api-reference/endpoint/apps/commit) to push a change first. On workspace-shared applications, the caller needs the Manager, Maintainer, or Administrator role.

The request is rate limited to 1 start per 3 seconds per application, and to 20 lifecycle actions per 15 seconds per user across all applications, with a 60-second block once that cap is hit.

### Parameters

<ParamField path="app_id" type="string" placeholder="Application ID" required>
  The ID of the application. You can find this in the URL of your application's dashboard.
</ParamField>

### Response

<ResponseField name="status" type="string">
  Indicates whether the call was successful.. `success` if successful, `error` if not.
</ResponseField>

<ResponseExample>
  ```json theme={null}
  {
      "status": "success"
  }
  ```
</ResponseExample>

### Common errors

| Code            | HTTP | Meaning                                                                     |
| --------------- | ---- | --------------------------------------------------------------------------- |
| `ACTION_FAILED` | 409  | The cluster rejected the action, for example the application is mid-deploy. |