A safety guardrail between an autonomous AI agent and PayPal. Every payment passes policy, a live-web merchant check, and intent reasoning before any money moves.
Every decision is appended to a hash-chained log: each record carries the hash of the one before it, so editing or dropping any row breaks every hash that follows. "Verify chain" re-checks the whole history. "Tamper (demo)" edits a row in place to show the break; "Reset ledger" rebuilds a clean chain.