Realer exposes control-device APIs for firmware that reads catalog state, reports physical state, and keeps the Realer UI synchronized with the device.
Control devices authenticate with OAuth 2.0 Client Credentials Grant. HTTPS responses include stable numeric response codes; MQTT acknowledgements include stable statuses and error labels. Use field semantics for retry, ordering, correlation, expiry, and result-handling rules.
HTTPS API requests must use HTTPS. MQTT runtime traffic must use MQTT over TLS. Plain HTTP and plain MQTT are not public control-device transports.
When using the Realer API as a control device developer, you are subject to developer responsibility.