Check a record

Every record this site publishes carries a reference and a fingerprint block. This page fetches the published file, recomputes the fingerprint from the same fields the anchoring step commits to, and — once a record has been written to a public network — reads the root back off that network and compares. The comparison runs in your browser, not on our server, which is the only version of this that is worth anything.

Nothing on this site is anchored yet. The anchoring step is built but has not been run against these pages, so every record still reads anchor.tx: null. This page says so per record rather than showing a tick that would mean nothing. The fingerprint it recomputes is real today and is worth keeping: when a record is anchored later, the fingerprint you saw must still match.

How the fingerprint is computed

A record's fingerprint commits to a fixed list of published fields, never to the file's bytes — so regenerating the site on the same day cannot move it, and a field added next year cannot silently change last year's value. The leaf is domain-separated from the tree's internal nodes by a one-byte prefix, so a leaf can never be replayed as a node.

// leaf = SHA-256(0x00 || utf8(canonical(subject)))
export async function leafHash(subject) {
  return sha256Hex(concat(LEAF_PREFIX,
    new TextEncoder().encode(canonicalize(subject))));
}
// node = SHA-256(0x01 || left || right)
export async function nodeHash(leftHex, rightHex) {
  return sha256Hex(concat(NODE_PREFIX, hexToBytes(leftHex), hexToBytes(rightHex)));
}
// proof = [{hash, position:'left'|'right'}], walked leaf -> root
export async function rootFromProof(leafHex, proof) {
  let h = leafHex;
  for (const step of proof)
    h = step.position === 'left' ? await nodeHash(step.hash, h)
                                 : await nodeHash(h, step.hash);
  return h;
}

What a match does and does not tell you

A match tells you the published record is byte-for-byte the record whose fingerprint was committed, and that it existed no later than the block that carries it. It tells you nothing about whether the record is right. An anchored sentence that is wrong is a wrong sentence with a timestamp, and on a site about rules and payment terms that is the misreading that matters.

The network named on these records is a test network (eip155:84532). A test-network anchor is a demonstration, not a claim that anything will persist.