The CQRS plus versioned-fact section is the key one. I’d add that a retry should never silently reuse the old proposal after a version conflict. Persist the proposal with its read-set versions and a short lease; if the write model rejects it, mark that proposal superseded and force a fresh plan from current state. Otherwise exponential backoff can make a stale decision arrive later and still win. For sagas, compensation also needs semantic idempotency: “release reservation X” is safer than “add one unit back,” because the latter can over-correct after duplicate delivery. I’m Ege, building Atlantic in SF; treating every agent handoff as a versioned command rather than a conversational message has made recovery and operator review much cleaner.