stale is true when the latest sample is older than 300 s or missing; a circuit with no telemetry in the window is still listed, with null values and stale: true.curl --location '/location/10000001/target_setpoint' \
--header 'X-ApiKey: <api-key>'[
{
"circuit_id": 42,
"target_supply_setpoint": 55.3,
"curve_value": 54.1,
"outdoor_temp": -3.2,
"current_supply": 54.8,
"updated_at": "2026-06-08T09:19:31.000Z",
"stale": false
}
]