Concepts

The whole vocabulary in one page. Deep detail lives in the spec.

The document

A transcript (a "UST") is a self-contained signed JSON object with a stable wire tag ust: "1.0". It carries:

id — who and what: domain_shard (a name like noosphere.md, or a self-certifying sha256: key-id), the ust_id frame, the key_id, and a class (observation, derivation, genesis, …).
ust_id — the time coordinate: ust:YYYYMMDD.HH[MM[SS]] in UTC. Not metadata — part of the document's identity. Containment is literal string prefixing (ust:20260710.14 ⊃ …1429 ⊃ …142900), so roll-ups are prefix scans and a time range is a string range. See Assurance Tiers and the README for why one shared axis matters.
time — an explicit frame: generated_at, valid_from, valid_to. valid_from == valid_to is an honest instant, not "expired" — UST 1.0 has no expiry rule.
data — one or more partitions, each captured / computed / blinded / encrypted.
hashes — one domain-separated hash per partition: H(tag, canon(...)), binding each value to the id and time. A plain SHA-256(text) will never match — the tag prefix is the point.
sig — an Ed25519 signature over the canonical bytes. It travels with the data, not the channel.
provenance (optional) — based_on, prev, seed: the links that make Chains and Layered Shards.
proof (optional) — an anchor inclusion proof (Bitcoin/OTS, Rekor) for the TOP tier.

genesis — the root document that binds a domain_shard to a key (a name-binding ceremony).
key-log — an append-only record of key rotation/revocation; you rotate by appending, never re-minting, so old documents stay valid.
witness — a served or logged list proving no rival genesis exists for the name (no-fork evidence). A publisher's own witness gives corroborated; independent non-membership gives authoritative.

anchor — external evidence that the document existed by a real point in time: an inclusion proof in a substrate (Bitcoin via OpenTimestamps, or Sigstore Rekor). Anchors commit to hashes, not contents — so payloads stay deletable while "existed, in this order" remains provable.

canon — the deterministic byte serialization (JCS-style) every implementation must agree on. ust canon prints it; the conformance vectors are the cross-language arbiter. Two conforming verifiers on the same bytes always agree.

UST