@buildtovalue/anchor-rfc3161

RFC 3161 timestamp anchor adapter (Handoff 8): anchors the ledger chain head to a TSA timestamp token, implementing the AnchorAdapter contract from @buildtovalue/identity.

The host owns the TSA transport (no network in the library)

You inject timestamp/verifyToken; the library never calls the TSA. This keeps the package network- and dependency-free and lets the host use its own TSA, credentials and validation policy.

import { createRfc3161Anchor } from '@buildtovalue/anchor-rfc3161';

const anchor = createRfc3161Anchor({
  async timestamp(digest) {
    return host.requestTsaToken(digest); // { token, genTime }
  },
  async verifyToken(token, digest) {
    return host.validateTsaToken(token, digest); // boolean
  },
});

const receipt = await anchor.anchor({ hash: head.hash, seq: head.seq });
await anchor.verify(receipt, currentHashAtSeq); // 'anchored' | 'mismatch' | 'unavailable'

Derive the UI state from the result via deriveAnchorState in @buildtovalue/identity. Consumes only @buildtovalue/identity — pinned by tests/independence.test.ts. Zero runtime dependencies.