Conflict-free booking across Google, Outlook, and Apple ; surfaced through REST, gRPC, MCP, or native CalDAV. Define your services, set your availability windows, and let Hermers handle the rest: free-busy resolution, appointment lifecycle, and iTIP dispatch to guests.
Every scheduling capability ; availability queries, appointment creation, service definitions, RSVP tracking ; is available through the same four access modes. Use the REST API from your backend, gRPC from your agent, MCP from your LLM, or CalDAV from your calendar app.
Full CRUD for services, appointments, guests, availability windows, and scheduling links over standard JSON HTTP.
Stream live appointment updates and availability changes for real-time UIs and AI agent polling.
Let your LLM check availability and book appointments on behalf of users, without ever touching raw calendar data.
Appointments appear directly in Apple Calendar, Thunderbird, or GNOME Calendar ; no separate integration needed.
Connect your Google, Outlook, Apple, or any CalDAV calendar. Hermers materializes a unified free-busy cache across all connected feeds. When you query availability for a participant, there is no live fetch ; the answer is already there.
Every connected feed is synced into a single busy-block table. Hermers detects conflicts before writing appointments and never double-books a slot.
Define when you're bookable with recurring weekly availability windows. Override specific dates to block time off, extend availability, or add one-off working hours.
Define what you offer ; a 30-minute intro call, a 60-minute consultation, a 15-minute check-in ; and let Hermers enforce the booking rules. Every appointment flows through a structured lifecycle from pending to confirmed to cancelled, with iTIP dispatch at each transition.
Service definitions describe what can be booked: the name, duration, buffer times, maximum guests, and which calendar it lands in. Create as many services as you need and expose them independently via scheduling links.
Every appointment moves through a structured state machine. Transitions fire atomic busy-block writes and iTIP email dispatches in the same atomic transaction ; no race conditions, no double-bookings.
Generate a scheduling link for any service. Share it with guests. They see real-time availability ; resolved against all your connected calendars ; and book directly into your Hermers calendar. No email chains, no copy-pasting times across time zones.
Every service gets a unique scheduling link. Customize the slug, set an expiry, cap the total bookings, and embed it anywhere. Links enforce all your availability rules in real time.
Every guest is tracked individually through the full RSVP lifecycle. Hermers fires iTIP METHOD emails automatically ; you never write scheduling email logic by hand.
From availability query to confirmed appointment with iTIP-notified guests, in four steps.
Hermers resolves availability across all connected calendar feeds. Slots are returned that fit your service duration, windows, and buffer rules ; in under a millisecond.
POST an appointment. Hermers writes a pending busy block atomically. The slot is soft-reserved immediately ; no race condition, no concurrent double-booking.
Confirm the appointment. The busy block hardens to confirmed. The calendar event is written. Guests are tracked at invited status, ready to RSVP.
iTIP REQUEST emails fire automatically. RSVP responses update the guest status in real time. Webhooks fire on every status change. Cancel at any time ; iTIP CANCEL goes out automatically.
Initialize a tenant, connect your Google or Outlook calendar, define a service, and generate your first scheduling link ; in under five minutes.
Connect a Calendar →REST endpoints, gRPC service definitions, MCP tool schemas, webhook event payloads, and iTIP integration guide ; all in one place.
Read the Docs →