{
  "$type": "com.atproto.lexicon.schema",
  "defs": {
    "externalAnchor": {
      "description": "Where firstSeenRoot was also published outside ATProto.",
      "properties": {
        "reference": {
          "maxLength": 2048,
          "type": "string"
        },
        "system": {
          "maxLength": 128,
          "type": "string"
        }
      },
      "required": [
        "system",
        "reference"
      ],
      "type": "object"
    },
    "main": {
      "description": "A timekeeper's record, once per epoch, of which records existed.",
      "key": "tid",
      "record": {
        "properties": {
          "beaconRound": {
            "description": "drand quicknet round that closed the epoch.",
            "minimum": 1,
            "type": "integer"
          },
          "createdAt": {
            "format": "datetime",
            "type": "string"
          },
          "externalAnchor": {
            "ref": "#externalAnchor",
            "type": "ref"
          },
          "firstSeen": {
            "description": "The leaves under firstSeenRoot.",
            "ref": "org.cairnsproto.draft.defs#external",
            "type": "ref"
          },
          "firstSeenRoot": {
            "description": "Merkle root of the CIDs first seen this epoch.",
            "ref": "org.cairnsproto.draft.defs#hash",
            "type": "ref"
          },
          "previous": {
            "ref": "com.atproto.repo.strongRef",
            "type": "ref"
          },
          "project": {
            "ref": "com.atproto.repo.strongRef",
            "type": "ref"
          }
        },
        "required": [
          "project",
          "beaconRound",
          "firstSeenRoot",
          "createdAt"
        ],
        "type": "object"
      },
      "type": "record"
    }
  },
  "id": "org.cairnsproto.draft.seen",
  "lexicon": 1
}