Anchors
Tzun can anchor records to a public ledger. Each record is sealed the moment it is captured; at intervals, one transaction then commits to the whole batch of records sealed since the previous one. This page lists the addresses allowed to send those transactions, and explains how to check a record against them.
Every publisher listed today is on Sepolia testnet, a public Ethereum test network. Anyone can read its blocks, but its coins have no value, so it lacks the economic security of a main network. Other networks are planned.
Every anchor names the log it belongs to, its anchor origin, for example demo.tzun.ai/<store id>/anchors. An anchor counts only if an address listed here for its origin sent it, between the dates shown.
Anchors this address sends for the origins below count as production.
Dry runs of the anchoring pipeline. Their anchors are tests, and are checked as tests.
Dry runs of the anchoring pipeline. Their anchors are tests, and are checked as tests.
Dry runs of the anchoring pipeline. Their anchors are tests, and are checked as tests.
Each anchor is one transaction from the publisher’s address to itself, moving no ether. Its Input Data is exactly 32 bytes, called P: a SHA-256 fingerprint of the batch’s checkpoint, which commits to every record in the logs it covers, in order. It costs at most 22,280 gas, however many records the batch holds.
Records never go on the chain, and neither do their fingerprints. No explorer can show you a record: the record, and the proof that ties it to a transaction, travel together in its proof bundle.
On a publisher’s address page, Etherscan lists each anchor as Transfer* (the * means the transaction carries Input Data). The same page also lists the incoming transfers that pay its fees. On the main network and the test networks alike, a block becomes final about 15 minutes after it is mined; until then, an anchor in it is not final.
Steps 1 and 2 prove that the batch’s fingerprint is public, and since when: the block’s time. They do not prove that your record is in that batch. Only step 3 does, because only it works from the record itself.
/anchors/publishers.json holds this list in the publisher manifest format that Tzun’s verifiers read. Each anchor origin maps to its publishers, each with address, chain (CAIP-2), namespace, validFrom and validUntil (both inclusive; null means no limit). It is served with Access-Control-Allow-Origin: *, so a tool on another site can read it.
SHA-256 of this version 7503124b866821417009bead4ff0f31eb98ba9ccdc7cc6fc92dd38eab9c9347b
A verifier should use its own copy, fixed when it is built or configured, rather than fetch this page while it checks. This site publishes the list; it is not what makes an anchor valid. Compare your copy’s SHA-256 with the one above.
An anchor whose origin starts with test. is a test, whatever this list says: calling yourself a test claims nothing. An anchor counts as production only when a production publisher listed here sent it.
The old entry gets an end date and a new entry is added. Old entries stay, so the anchors they sent can still be checked. A transaction sent after its publisher’s end date does not count.