# List device observations

> A historical result: a measurement plus its target, source and revision.

`GET https://api.cymatics.tech/v1/devices/{device}/observations`

Scope: `results:read`

## Request

Send your key as `Authorization: Bearer cym_test_…`. Requires the `results:read` scope. Test keys read the simulator; live keys read your paired Cymos.

| Name | In | Type | Required | Description |
| --- | --- | --- | --- | --- |
| `device` (SDK and CLI: `device_id`) | path | `string` | Yes | Device id |
| `from` | query | `string (date-time)` | No | From |
| `to` | query | `string (date-time)` | No | To |
| `limit` | query | `integer, ≥ 1 and ≤ 1000` | No | Limit |
| `cursor` | query | `string` | No | Cursor |

## Response

`200 · application/json`

```json
{
  "data": [
    {
      "value": 1,
      "timestamp": "2026-10-24T23:55:30.000Z",
      "confidence": 0.92,
      "object": "result",
      "id": "res_01",
      "signal": "heart_rate_bpm",
      "room_id": "room_bedroom",
      "device_id": "dev_bedroom",
      "track_id": "trk_001",
      "person_id": "person_001",
      "model": {
        "id": "model_vitals",
        "version": "demo-1"
      },
      "received_at": "2026-10-24T23:55:30.000Z",
      "updated_at": "2026-10-24T23:55:30.000Z",
      "revision": 1
    }
  ],
  "meta": {
    "request_id": "req_01",
    "project_id": "proj_demo",
    "livemode": false,
    "generated_at": "2026-10-24T23:55:30.000Z"
  },
  "page": {
    "has_more": false,
    "next_cursor": "cur_01"
  }
}
```

## Errors

| Status | Description |
| --- | --- |
| `429` | `rate_limit_exceeded`: Too many requests this minute for the key (or twice that across the project), or too many open streams for the project. Retry after the seconds in Retry-After.<br>`quota_exceeded`: A live key's project has used its monthly live-hour cap. There is no Retry-After. Don't retry; raise the live-hour cap in the dashboard. Headers: Retry-After, RateLimit-Limit, RateLimit-Remaining, RateLimit-Reset. |
| `503` | `live_unavailable`: This operation has no live data for this project yet (for example, no paired Cymo covers it). Don't retry the same request; pair a Cymo that covers it, or build against a test key.<br>`service_unavailable`: A dependency, such as API key verification, is unreachable, or the project is busy with another write. Retry after the seconds in Retry-After, with backoff. |
| `4XX` | Invalid request, credential, permission or revision. |
| `default` | Error with a stable code and request ID. |

Every error is a `{ error, meta }` envelope with a stable `code`. See [Errors](https://docs.cymatics.tech/errors) for each code and whether to retry.

## Call it

**TypeScript · @cymos/sdk**

```ts
import { Cymo } from "@cymos/sdk";

const cymo = new Cymo({ apiKey: process.env.CYMO_API_KEY! });

const { data, meta } = await cymo.devices.observations.list({
  device_id: "dev_bedroom"
});
```

**terminal · cymatics CLI**

```sh
$ cymatics devices observations list --device-id dev_bedroom --json
```

**curl**

```sh
curl "https://api.cymatics.tech/v1/devices/dev_bedroom/observations" \
  -H "Authorization: Bearer $CYMO_API_KEY"
```

**MCP tool**

```
list_device_observations({ device_id: "dev_bedroom" })
```

The MCP tool `list_device_observations` calls this operation with your key.