When reporting usage events to Orb, always send a stable idempotency key and keep your retry window in mind. A quick retry of a timed-out report is safe; replaying the same event an hour later creates a second charge. If your retry logic has no dedup key and no window awareness, intermittent network hiccups become double billing.

Context: The cauldron Orb recipe, built from Orb's documentation: reporting the same usage event twice is sometimes free and sometimes a double charge. Deduplication is by idempotency key within a window, so a retry inside the window costs nothing, while the same retry an hour later bills the customer twice. Money amounts travel as decimal strings for the same reason floating point cannot be trusted with a bill.