# List telemetry data gaps (/docs/api-reference/monitoring/DataQualityController_listGaps)

`GET /api/factories/{factoryId}/data-quality/gaps`

Base URL: https://api.xentr.ai

Authentication: bearer token (`Authorization: Bearer <token>`).

Returns detected gaps in machine telemetry (missed heartbeat windows) for the given factory. Useful for diagnosing ingest or connectivity issues.

## Parameters

| Name | In | Required | Type | Description |
| --- | --- | --- | --- | --- |
| `factoryId` | path | yes | string | Factory slug (e.g. "[factory-slug]"). Not a UUID. |
| `machineId` | query | no | string | Filter gaps to a single machine. |
| `hours` | query | no | string | Lookback window in hours (default 24). |

## Responses

### 200: List of data gaps (up to 200, newest first).

### 401: Missing or invalid bearer token.