Reading a receipt requires at least $0.07 of credit available; otherwise you see API Error: Not Enough Credits Please Refill. The charge for the scan is the larger of $0.04 per extracted line item or seven times the underlying AI cost plus $0.02 per item, and it is recorded in your Sprwt AI history as Receipt/Invoice Image Analysis (N items). Calculating macros costs $0.07 per ingredient; the bulk confirm checks your balance first and shows an insufficient-credits window if it is too low. Auto-recharge, if enabled on your account, tops up before charging.