# Occupancy Sensors

Occupancy sensors can determine whether a parking space is occupied by a vehicle. A common application of these sensors is to monitor and display real-time parking spot availability.

**Note:** For the sake of flexibility and extensibility the API only accepts **string** values. Invalid data types (e.g., numbers) will be rejected.

For example, an `occupancy` sensor only accepts:\
✅ `"true"`  ✅ `"false"`  ✅ `"null"` ❌ `123` ❌ `"invalid_value"`

### What about the Charge Point?

The `chargePointId` associated with the sensor is updated based on the sensor value. When a charge point sensor  of type `occupancy` is set to `true`, the charge point is considered occupied, and its state transitions to `busy_blocked`. When the sensor is set to `false`, the charge point can transition to other states.

To check the current state of a charge point, you can use the [Charge Points API](/api/charge-points#retrieve-a-single-charge-point) to retrieve the `state` and `occupied` fields.