REST API
Integrate booking into your own systems
Your users should book appointments without leaving your platform – under your brand, with your IDs. The timum API covers the full lifecycle: from the organisational structure to the consumer booking. These are exactly the endpoints the BookingJs widget books with in production every day – more than 2,000,000 participants have been coordinated over timum's infrastructure.
API access on request – included in the annual plans. One phone call is enough.
How It Works
Request an API key
One phone call is enough – API access is part of the annual plans. You receive the key for the X-TIMUM-CLIENT-ID header. It is bound to your crmId, which every Partner API path carries as a parameter.
Create structure and offering
Initial Setup (users, accounts, providers, staff), then Configure Offerings (properties, appointment types, contact profiles).
Let them book
Booking Flow: fetch upcoming_bookables → reserve_appointment (3-minute hold) → create_appointment_with_consumer.
Key Benefits
Fully programmatic: users, accounts, providers, properties, appointment types, timeslots and bookings via REST – authenticated with the X-TIMUM-CLIENT-ID header.
Your IDs stay authoritative: the reference format {uniqueId}@{platformName} saves you mapping foreign keys – you reference entities with the IDs of your own system.
Open Booking API without an API key for your consumer frontend – the same endpoints as in the widget, including the 3-minute reservation.
JSON, CORS, precise status codes: an appointment already taken responds with 412 Precondition Failed instead of a race condition – hosted in Frankfurt.
Who Needs This Feature?
See how this feature helps different users
Booking natively in your own website
Your agency builds the appointment picker straight into your web presence – via the Open Booking endpoints, without the widget layout and without an API key.
Appointment booking as a product feature
CRM and portal providers integrate appointment coordination under their own brand. timum stays invisible to end customers; users cost nothing, you pay for what is bookable.
The property developer's prospect portal
The project portal creates one bookable property per unit and books viewings via the API – the unit IDs from its own system remain the reference.
Related Features
Build appointment booking into your product
Free for 30 days. No credit card required.