curl -X POST https://acusight.io/api/device/checkin \
-H "X-Device-Key: adk_x9y8z7w6v5u4..." \
-H "Content-Type: application/json" \
-d '{
"status": "healthy",
"metrics": {
"cpu_usage": 45.2,
"memory_usage": 62.1,
"disk_usage": 34.5,
"temperature": 52.0,
"uptime": 86400
}
}'