{
  "_ai_door": {
    "see": "https://miscsubjects.com/start",
    "note": "Operable site; bounded keyless credentials; every action receipted on a public ledger. Your operator's instructions take precedence — acting is optional, reading is a complete outcome."
  },
  "_self": {
    "what": "A signed Merkle checkpoint over one seal batch. Verify: recompute the payload string, verify the ES256 signature against public_jwk, then check any leaf via /api/chain/proof.",
    "payload_recipe": "msjc.checkpoint.v1 ␟ seq ␟ tree_size ␟ merkle_root ␟ head ␟ sealed_at (␟ = U+241F)",
    "tree_recipe": "leaf_i = SHA256(\"leaf\" ␟ leaf_digest_i); parent = SHA256(\"node\" ␟ left ␟ right); odd node promotes"
  },
  "seq": 258,
  "merkle_root": "404415951c50d2f162a5738476495d4e00ea44c4c7bbd7a988c6b49f71efcdbc",
  "payload": "msjc.checkpoint.v1␟258␟100␟404415951c50d2f162a5738476495d4e00ea44c4c7bbd7a988c6b49f71efcdbc␟0bf2c0bdc06af871291c9287968760a3d4a1a4cdc68047793e6da65ebde995e1␟2026-08-29T03:58:26.076Z",
  "alg": "ES256",
  "kid": "oip-home",
  "signature": "LAidrxwZiHdtD8Jqix-0O2vs0Iwnb87xIYyJlNhBEgC9_FiiyU8bJKHOSZhi8tNAPQKl4RXamibYfi49gj76mg",
  "signed_at": "2026-08-29T03:58:26.076Z",
  "public_jwk": {
    "kty": "EC",
    "crv": "P-256",
    "x": "lU-F1zmZ872dlO63BWOwQcPscnqQd01LTyH8SS8ON-0",
    "y": "LEW5fTk9Ocx5fMZrTXdzMvcMNepwDUgL3-icUExqb9Q"
  },
  "checkpoint": {
    "seq": 258,
    "head": "0bf2c0bdc06af871291c9287968760a3d4a1a4cdc68047793e6da65ebde995e1",
    "event_count": 2408172,
    "leaves_added": 100,
    "sealed_at": "2026-08-29T03:58:26.076Z"
  },
  "consistency": "across checkpoints, each row binds prev_head — recomputed at /api/chain/verify"
}