Booking API — Free calendar scheduling with availability slots

Features

Full-featured scheduling without the SaaS price tag.

Service configuration

Define services with duration, buffer time, capacity, and pricing. Multi-locale names supported.

Availability rules

Set weekly rules by day-of-week with start/end times. Support morning + afternoon splits per day.

Availability exceptions

Override rules for specific dates — holidays, special hours, one-off events.

Slot generation

Algorithmically computes available time slots from your rules, duration, and buffer time.

Turnstile captcha

Bot protection on the public booking endpoint via Cloudflare Turnstile.

CSV export

Export all bookings as CSV with customer details, timestamps, and status.

Use cases

Any business that schedules appointments can use NexusKit Booking.

Consulting & coaching

Let clients book 30-minute or 1-hour sessions against your availability.

Service businesses

Salons, repair shops, agencies — let customers pick a time slot online.

Team scheduling

Internal scheduling for interviews, demos, or office hours with group capacity.

Event bookings

Manage small events, workshops, or classes with capacity limits and buffer time.

How the API works

Set up services, configure availability, and let customers book in three steps.

1. Create services

Define your services with duration, buffer time, capacity, and pricing.

POST /v1/booking/services
{
  "names": { "en": "30-min Consultation" },
  "durationMin": 30,
  "bufferMin": 10,
  "capacity": 1,
  "priceCents": 5000,
  "currency": "EUR"
}

2. Set availability

Configure weekly rules and date-specific exceptions.

POST /v1/booking/availability
{
  "rules": [
    { "day": 1, "start": "09:00", "end": "12:00" },
    { "day": 1, "start": "14:00", "end": "17:00" }
  ],
  "exceptions": {
    "2025-12-25": null
  }
}

3. Customers book

Public endpoints let customers fetch available slots and create bookings.

GET  /v1/public/booking/services/:id/slots?date=2025-07-15
POST /v1/public/booking/bookings
{
  "serviceId": "...",
  "startsAt": "2025-07-15T09:00:00Z",
  "customer": { "name": "Jane", "email": "[email protected]" }
}

FAQ

Does Booking support time zones?

Yes. Each tenant has a timezone field (default UTC). Slot calculation uses UTC timestamps so bookings are consistent across time zones.

Is NexusKit Booking free?

Yes, within fair-use limits — 5,000 bookings per month, 120 requests per minute.

Can I set different prices per service?

Yes. Each service has a priceCents field and currency (default EUR). Set to null for free services.

How does group booking work?

Set capacity greater than 1 on a service. The slot algorithm will allow that many concurrent bookings per time slot.

Can I block off specific dates?

Yes. Use availability exceptions to override weekly rules for holidays, special hours, or one-off events.

Booking