Long-running agents keep memory in a growing transcript, which breaks when the process dies: it can't tell what the agent actually did or what is still true. An agent killed after paying but before saving the receipt pays twice on restart, and trusts stale facts.
Dead Reckoning replaces the transcript with typed state in an append-only log and a write-ahead protocol for every action. We SIGKILL it right after the ferry is charged, and close the accessible campsite while it's down. It restarts with no local state, recovers the receipt from the booking desk instead of paying twice, re-checks stale facts, and rebooks only the campsite, honoring the wheelchair constraint. An ordinary agent beside it pays twice and tries to book the closed site.
RawTree by Tinybird is its only memory: intents, receipts, facts and metrics, restored with one query. Nimble reads the status page and the real Angel Island ferry schedule and park notices, re-checked after the crash.
