<p>Sets the user interface (UI) customization information for a user pool's built-in app UI.</p> <p>You can specify app UI customization settings for a single client (with a specific <code>clientId</code>) or for all clients (by setting the <code>clientId</code> to <code>ALL</code>). If you specify <code>ALL</code>, the default configuration is used for every client that has no previously set UI customization. If you specify UI customization settings for a particular client, it will no longer return to the <code>ALL</code> configuration.</p> <note> <p>To use this API, your user pool must have a domain associated with it. Otherwise, there is no place to host the app's pages, and the service will throw an error.</p> </note>

{
  "success": true,
  "data": {
    "id": "abc123",
    "created_at": "2025-01-01T00:00:00Z"
  }
}

{
  "success": false,
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid request parameters"
  }
}

<p>Sets the user interface (UI) customization information for a user pool's built-in app UI.</p> <p>You can specify app UI customization settings for a single client (with a specific <code>clientId</code>) or for all clients (by setting the <code>clientId</code> to <code>ALL</code>). If you specify <code>ALL</code>, the default configuration is used for every client that has no previously set UI customization. If you specify UI customization settings for a particular client, it will no longer return to the <code>ALL</code> configuration.</p> <note> <p>To use this API, your user pool must have a domain associated with it. Otherwise, there is no place to host the app's pages, and the service will throw an error.</p> </note>

{
  "success": true,
  "data": {
    "id": "abc123",
    "created_at": "2025-01-01T00:00:00Z"
  }
}

{
  "success": false,
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid request parameters"
  }
}