Stripe Credit & Usage-Based Billing, Already Built
Usage and credit billing is the most error-prone part of a SaaS: top-ups, ledgers, mid-cycle proration on upgrade, and never letting a balance go negative. This template ships all of it.
The credit model, end to end
Each plan grants a credit allowance per cycle, and buyers can purchase one-time top-up packs via Stripe Checkout when they run low.
Every grant and every spend is a row in a credit ledger, so balances are auditable and a user can never spend below zero.
Charge credits for any action — an image generated, an API call served — with a single consume call that records it.
Mid-cycle upgrade proration, handled
The hard case is upgrading mid-cycle. Simple Stack grants the difference between the new and old plan allowance — the new−old delta — and keeps the existing billing cycle, with guards so the same upgrade cannot be replayed to farm free credits. It is the kind of logic that quietly leaks money when hand-rolled.
There is also an API-key-gated metered API variant: sell your API and charge credits per request, with rate limits and a usage log. See the subscription SaaS starter for how plans and tiers fit around it.
Stripe handles payments — you build the credit logic
| This template | Raw Stripe | |
|---|---|---|
| Take payments & subscriptions | ||
| Credit allowance per plan | × | |
| Auditable credit ledger | × | |
| Mid-cycle upgrade proration | × | |
| Top-up packs | ~ | |
| Per-action metering hook | × |
Run a metered action and watch the ledger.
The credits and API demos are fully interactive — no card, nothing saved.