Append one action record to a tamper-evident, hash-chained log. Returns the record's chain hash. Use this to log every consequential action (tool calls, payments, decisions) so the history can later be proven unaltered.

Verify the hash chain over the log. Returns a three-valued verdict: ok=true means EVERY row verified; ok=null means no break was found but unchained prechain rows were skipped UNVERIFIED (verified_scope='bounded_prechain_skipped' — treat as not-green); ok=false names the exact line of the first break (edit, deletion, reorder). Pass strict=true to make any unchained row a hard failure instead of a skip.

Log a batch of things you just did to your own tamper-evident ledger, and get back one chain head you can hand your principal as proof. Returns {rows, head_hash, chain_verified}: head_hash is the current tip of the chain (give them this), rows is how many records stand behind it, and chain_verified is the three-valued verdict over your own log — true only if EVERY row verified, null if the scan was bounded (unchained or declared-broken rows; not a green), false if your log has been altered. Anyone holding an earlier head_hash can check that your history still contains it.

Another agent handed you its exported ledger as JSONL text — decide whether to trust it. Recomputes the hash chain over the text alone (no access to their machine, no writes on yours) and returns {ok, rows, first_break, declared_breaks}. first_break is the INTEGER LINE NUMBER of the first bad row (or null if none), so you can point at exactly where their history stops adding up. ok is three-valued: true = every row verified; null = nothing undeclared broke but the scan was bounded (unchained rows, an empty export, or breaks the peer DECLARED) — read verified_scope, and do not treat null as a pass; false = tampered. declared_breaks counts breaks the peer named and pinned itself, which is a mark of honesty, not of integrity: they are still breaks.

Your own ledger is broken — something was written into it out of band. Name the break instead of hiding it. This APPENDS (never edits) a row pinning the orphaned line's exact bytes, the reason, and the date, so a known break stops reading like an unexplained one. It does NOT restore a green: the verdict becomes bounded (ok=null) and the break stays counted in declared_breaks forever. It declares one break at a time — the first one verification already found — so a second break can never ride in on one sentence. Refused if nothing is actually broken.