The Opencals Storefront API is now public!
It's a clean REST API and typed TypeScript SDK for building fully custom booking websites – browse services, check real-time availability (single slots or date ranges for rentals), filter by staff and location, collect Stripe payments, and manage customer accounts. All the hard parts – double-booking, timezones, multi-staff and multi-location logic – are handled server-side.
Most booking tools treat services as simple calendar appointments. Real service businesses are far more complex.
Opencals is service commerce infrastructure that models services as operational inventory - computing availability across staff, locations, capacity, and rules.
Bookings become real transactions tied to orders, payments, and customers, enabling multi-location operations, rentals, group services, and complex scheduling without workarounds.
OpencalsThe booking engine for real service businesses