Control Tuya smart devices via the Tuya Cloud API using access credentials and request signing

Steps

1. Register on platform.tuya.com, create a Cloud Project, and note the Access ID and Access Secret; add your Tuya-connected devices to the project and select the Smart Home or Industry Basic Service API products
2. Obtain an access token by POST to https://<endpoint>/v1.0/token?grant_type=1; the endpoint varies by region (e.g., openapi.tuyaus.com for US, openapi.tuyaeu.com for EU); sign the request with HMAC-SHA256 using the Access Secret over a string composed of Access ID, timestamp, nonce, and the request body hash
3. List devices associated with the user by GET /v1.0/iot-01/associated-users/devices after linking devices to the project via the Tuya app or Smart Life app; note each deviceId for subsequent commands
4. Retrieve device function specifications with GET /v1.0/iot-03/devices/<deviceId>/specification to get the supported Codes (e.g., switch_led, colour_data, temp_value) and their value schemas
5. Send a device command with POST /v1.0/iot-03/devices/<deviceId>/commands with body {"commands":[{"code":"switch_led","value":true}]}; include a fresh access token and re-sign each request with the current timestamp
6. Poll device status with GET /v1.0/iot-03/devices/<deviceId>/status for a snapshot, or use Tuya's Pulsar message queue service to subscribe to device event streams for real-time updates