# List effective observation ids by device

Canonical page: https://docs.ovok.com/api/slim/telemetry/list-effective-observation-ids-by-device

`GET /v1/slim/telemetry/effectiveIds`

Returns the effective Observation ids for every device in your project, keyed by device identifier. These are the readings that produced each device's current heart rate, respiratory rate, sleep status and presence values.

**Auth:** bearer token. The caller must be a practitioner, an admin or a System Owner, and needs `Device:read` and `Device:search`.
**Scope:** the caller's project (from the token).

## Behaviour

- Covers the devices that have telemetry, up to the first 1000 devices of the project, including devices without a resident.
- Each value has the same shape as `GET /v1/slim/telemetry/{deviceId}/effectiveIds`. Fields are `null` when no reading has set them.

## Example

```bash
curl -X GET 'https://api.sandbox.ovok.com/v1/slim/telemetry/effectiveIds' \
  -H 'Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpYXQiOjE3NjcyNjg4MDAsImV4cCI6MTc2NzI3MjQwMH0.Ql3B_ztDvctlyZ2z0vp4sl3ExXRQGkzmxdmTAqxNzZk'
```