A booking system that can't double-book.

Slotly is a complete, self-hosted appointment booking system for salons, spas, barbers, trainers, tutors, consultants — any service business that books time. Your clients book in seconds from a beautiful widget; you run everything from a clean admin. One-time purchase, your server, your data.

THE ENGINE IS THE DIFFERENCE
Cheap booking scripts fall apart on scheduling logic — double-bookings, timezone bugs, ignored buffers. Slotly's engine ships with an automated test suite you can run yourself (42 assertions + a parallel-request race test): no double-booking guaranteed at the database level, timezone & DST correct, buffers enforced, blackout dates, minimum notice, booking windows, split shifts, group-class capacity, and atomic rescheduling that keeps payment history intact.

WHY SELF-HOSTED
Booking SaaS charges $15-30/month forever and owns your client list. Slotly is bought once and runs on the hosting you already pay for. Backup = one database.

TECH
Plain PHP 8 + MySQL (SQLite also supported). No framework, no Composer, no build step, no external APIs. Clean, readable code that's easy to extend. 2-minute web installer. Docker image included.

WHAT'S INCLUDED
Full source code, web installer, demo data, Dockerfile, email templates, engine test suite, written install & deploy guide (README + documentation.html in the download), 6 months support.

LIVE DEMO
Booking widget: https://slotly.ownware.io/ · Admin: https://slotly.ownware.io/admin/login — [email protected] / admin123 (demo resets hourly)

- Multi-step booking widget (service → staff → date → time → details), mobile-friendly, "any available" staff option
- No double-booking — enforced at the database level, proven by a parallel-request race test
- Timezone & DST aware — clients book in their timezone, you work in yours
- Per-service buffers, blackout dates/time-off, minimum notice, booking window, slot interval, optional approval step
- Group classes with capacity; never one booking over
- Deposits (% or fixed) quoted at booking and tracked in admin; coupon codes; tax; integer-cents money math
- Customer self-service — secure link to view / reschedule / cancel (cutoff enforced); rescheduling is atomic
- Admin: dashboard, colour-coded week calendar, appointment statuses, record payments, walk-ins, customers with history
- Staff with working hours incl. split shifts, time off, per-service assignment, admin/staff roles
- Reports by service and staff; monthly revenue
- HTML email: confirmations, admin alerts, reschedule/cancel notices, automatic reminders via one cron line (SMTP or PHP mail)
- Branding — name, logo, accent colour flow through widget + emails
- 2-minute web installer, one-click demo data, Dockerfile included

- PHP 8.0 or newer, with the PDO extension (standard on virtually all hosts)
- MySQL / MariaDB database — or SQLite (bundled with PHP, zero setup)
- Any Apache or LiteSpeed shared host with mod_rewrite, or Nginx / VPS
- No Composer, no Node, no build step, no external services required

1. Upload the contents of the app/ folder to your web root (e.g. public_html).
2. Visit your domain — you are redirected to the web installer.
3. Enter database details (MySQL, or SQLite for zero setup), business name, timezone and admin login. Click Install.
4. Sign in at /admin/login, add staff + working hours and your services; your public booking page is live at your domain root.
5. Optional: php bin/demo.php loads a realistic sample salon. Add one cron line (cron/reminders.php, hourly) for automatic reminder emails.
Manual alternative: copy config.sample.php to config.php and edit. Local trial: php -S localhost:8000 router.php. Full details in README.md / documentation.html inside the download.