Credits vs subscription, and credit packs
A subscription adds credits every cycle; a pack is a one-time top-up. Both land in the same balance.
Subscription credits and pack credits go into the same balance and are spent the same way. Every AI action shows its price before you run it.
Add credits each billing cycle, roll over unused credits up to a cap, and unlock the plan's features. Manage them under Settings → Billing (Stripe) or in your iPhone's Subscriptions (Apple).
One-time top-ups when you run short. On the web from Settings → Billing → Buy credits; on the iPhone as an in-app purchase. Packs never expire while the account is open.
Settings → Billing → Activity lists every charge, refund and grant with the action that caused it.
Actions that cost more than you have show a message with the shortfall and the fastest way to top up.