The engine, runningin your browser.
Pick seats. Watch the hold timer. Change who pays the fee. Check out and see the double-entry ledger balance to zero. There is no product UI yet — this is the commerce core made touchable so you can judge whether the money and inventory logic behave the way you want before any screens get built on top.
This is not a mock-up. The pricing and ledger code below is the
production module, bundled unmodified from
apps/api/src/money/ —
the same file the 38 pricing tests and 20 checkout tests run against. Only the storage
differs: in-memory here, PostgreSQL on the server.Seat map · The Fillmore (demo venue)
Stage
Available
Your hold
Held by someone else
Sold
Blocked (artist hold)
“Simulate a rival buyer” grabs a random available seat — the same contention the concurrency tests prove against a real database.
Event log
Order
Double-entry ledger
Complete a purchase to post the entries.
Tickets issued
None yet.