How we build · Our own builds
How We Built a Credit-Based Billing System That Can’t Double-Charge, Now Powering Our Own Live Checkout
An atomic credit ledger and idempotent payment-webhook handler turned usage-based billing from a risk into a solved problem.
How we did it
- Step 1Atomic Credit Ledger
A credit balance can never drift from what was actually paid for.
- Step 2Idempotent Webhooks
A retried payment event can never charge twice.
- Step 3Proven in Production
First built for our own scheduling assistant’s pay-as-you-go credits.
- Step 4Now Powers Our Storefront
The same engine now meters our own live Stripe checkout.
Credit Metering + Stripe Billing Kit
Credit metering and Stripe billing for AI apps, with the reset and webhook defects fixed.
See Credit Metering + Stripe Billing Kit, from $447
Not sure it fits? The free Business Checkup shows what’s costing you money and what to fix first.
More of our own builds
Client names are withheld by default and replaced with an industry description throughout — the work speaks for itself either way.