Build and register a SmartThings Schema Cloud Connector (webhook-based) to integrate a custom cloud-connected device

Steps

1. Register a new Schema Cloud Connector in the SmartThings Developer Center (not the legacy Developer Workspace, which ended Schema support in August 2025), providing a webhook URL and OAuth 2.0 client credentials
2. Implement the webhook endpoint to handle the five interaction types: discoveryRequest, stateRefreshRequest, commandRequest, grantCallbackAccess, and integrationDeleted
3. In the discoveryRequest handler, return a device list payload describing each device with its externalDeviceId, friendlyName, deviceHandlerType, and manufacturerInfo
4. In stateRefreshRequest, query your cloud for current device state and return the mapped SmartThings capability attributes (e.g., switch: on/off, level: 0-100)
5. In commandRequest, translate SmartThings capability commands into your cloud's API calls, then return the updated state
6. Test the integration in the SmartThings mobile app by linking the account; verify devices appear and commands round-trip correctly