The till
A checkout that cannot charge twice
Most point-of-sale trouble starts with a sale that half-committed. MultiPOS submits checkout with an idempotency key and writes everything the sale touches inside one database transaction.
- Retried submissions resolve to the same sale
- Sale, payments, balances and ledger commit or roll back together
- Partial and credit tenders settle against the customer account
- Registers open and close with counted cash and recorded variance
One checkout writes
- sales
- 1 row
- sale_payments
- 1–n rows
- inventory_balances
- updated
- stock_ledger
- append-only