# v1 · EvidenceReference

[All API schemas](/api-reference/v1/schemas/)

<code>object</code> — Additional properties rejected

| Field | Required at this level | Type | Description and constraints |
| --- | --- | --- | --- |
| <code>id</code> | Yes | <code>string</code> | — |
| <code>kind</code> | Yes | <code>string</code> | — |
| <code>contentHash</code> | Yes | <code>string</code> | Pattern: <code>^0x&#91;0-9a-fA-F&#93;{64}$</code> |
| <code>observedAt</code> | No | <code>string</code> | Format: <code>date-time</code> |
| <code>freshness</code> | Yes | <code>string</code> | Allowed: <code>CURRENT</code>, <code>STALE</code>, <code>DEGRADED</code>, <code>HISTORICAL</code>, <code>UNAVAILABLE</code> |

Nested required fields apply when their parent object or matching union branch is present. Named types link to their complete schema.

Exact definition: <code>#/components/schemas/EvidenceReference</code> in the [OpenAPI contract](/openapi/liquidity-studio.openapi.json).