Versions & glossary
One page that answers «what version is this receipt» and «what does this word mean».
If a document on this site disagrees with this page, this page is right - and that is a bug to report.
Receipt (PDR) versions
| Byte | Name | Size | What it means |
|---|
0x03 | PDR v2.3 | 239 B | Ordinary receipt. Signed by the notary only. payload_hash = work_hash: the file's SHA-256 is visible in the receipt. Used by the free tier and by both paid rails after 10.11.2026. |
0x04 | PDR v2.4 (bilateral) | 239 B | Receipt with two signatures: the agent (browser key) and the notary. payload_hash = sha256(work_hash ‖ agent_sig ‖ agent_pubkey) - a binding commitment, not the file hash itself. Issued by the MCP agent flow; web receipts before 10.11.2026 are also of this kind (history). |
Anchoring
- Anchor epoch - one NEAR transaction per hour committing the Merkle root of the log up to that moment. The log is cumulative: each root covers every leaf from the first one.
- Leaf - one record in the log: a receipt, a time attestation, or a snapshot. Leaves are ordered by
log_index; the tree is RFC 9162 (leaf = SHA-256(0x00‖data), node = SHA-256(0x01‖left‖right)).
AOT-EV1
- AOT-EV1 v0.1 - a signed bundle format for claims («who says what, until when») that fills the
evidenceHash slot of ERC-8325. Standalone library, Apache-2.0, not part of the notary service. Bridge page: AOT-EV1 bundles.
Glossary
| Term | Meaning |
|---|
| PDR | Portable Data Receipt - the 239-byte receipt: version, payment type, timestamp, issuer, subject hash, payload hash, Merkle root, anchor tx, notary signature. |
| Anchor | An hourly NEAR transaction that commits the current Merkle root of the whole log. It is what makes «existing at T» independent of us. |
| Reaffirmation | A second (or later) registration of the same file hash. It adds a new timestamp; it does not outrank the first record. |
| Binding hash | In 0x04 receipts: sha256(work_hash ‖ agent_sig ‖ agent_pubkey). It commits to the artifact without publishing its SHA-256. In 0x03 receipts the binding hash equals the file hash. |
| Epoch 2 | Internal name of the cumulative anchoring mode (roots cover the whole log, not a single batch). Live since June 2026. |
| EV1 | AOT-EV1 - the evidence bundle format described above. |