Stripe-parity billing simulator
Tera computes every invoice with Stripe's own billing rules and proves it against real Stripe test clocks, so you see what each customer pays before you ship the change.
The problem
Prorations, coupons that run out, tax rounding and anchors that move are where invoices go wrong, and Stripe's docs leave many of those rules unwritten. Tera models them, and every one is backed by a scenario Stripe itself has billed.
What it does
Simulator
Upgrades, seat changes, coupons, trials, taxes, pauses, cancellations: put a customer through them on a timeline and read each invoice to the cent, with the webhook events Stripe sends for it.
Open the simulatorPricing builder
Type prices, coupons and tax rates, or import the connected test account's catalog, then simulate on it. Push it back to Stripe test mode idempotently.
Build a catalogMigration planner
Move a customer base to a new price and see the MRR impact, grandfathering and each account's difference, from a CSV or the live subscriptions in Stripe.
Plan a migrationWhy Tera
Every golden scenario is replayed against Stripe with test clocks; a single cent of difference fails CI.
TestSprite, Playwright journeys and a Stripe differential fuzzer run on every pull request.
An MCP server with 10 tools, an OpenAPI 3.1 REST API and llms.txt, all on this deployment.
12-decimal unit proration, invoice-level tax rounding, the renewal draft hour: found by fuzzing, written down.
Start here
No signup. Pick a golden scenario or build your own, then press Verify in Stripe to replay it on a real test clock.