# Kennismakingsgesprek with Mathew Groen

> Een kort gesprek van een kwartier over wat je wilt uitleggen en aan wie. Je hoeft niets voor te bereiden, en past een sketchvideo niet bij je vraag, dan zeg ik dat eerlijk. A short fifteen-minute call about what you want to explain and to whom. Nothing to prepare, and if a drawn video isn't the right answer, I'll say so.

- Host: Mathew Groen
- Duration: 5, 10, 15, 20, 25, 30 min
- Location: Cal Video
- Host time zone: Europe/Amsterdam
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/mathew-groen/kennismakingsgesprek
- Event type id: 5915988

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=5915988&start=YYYY-MM-DD&end=YYYY-MM-DD&timeZone=<IANA time zone>
cal-api-version: 2024-09-04
```

The response is `{"data":{"YYYY-MM-DD":[{"start":"<ISO 8601 with offset>"}]}}`; no API key is needed.

## Book

```http
POST https://api.cal.com/v2/bookings
cal-api-version: 2026-02-25
Content-Type: application/json

{
  "eventTypeId": 5915988,
  "start": "<UTC ISO 8601 start from the slots response>",
  "lengthInMinutes": 15,
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "guests": [
    "guest@example.com"
  ],
  "bookingFieldsResponses": {
    "notes": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address)
- Optional fields: `notes` (Additional notes), `guests` (Add guests)
- `name` and `email` go in `attendee` and `guests` is a list of emails; every other field goes in `bookingFieldsResponses` under its name.
- `lengthInMinutes` picks one of 5, 10, 15, 20, 25, 30; pass the same value to the slots request as `duration`.