# Groeicheck with Sebastiaan Vreeken

> Dertig minuten over jouw groei. We kijken waar je groei nu lekt: zichtbaarheid, website, campagnes, opvolging en meting. Aan het eind weet je of het groeitraject bij jullie past, en zo niet, wat dan wel. Geen pitch.

- Host: Sebastiaan Vreeken
- Duration: 30 min
- Location: Cal Video
- Host time zone: Europe/Amsterdam
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/sebastiaan-vreeken/groeicheck
- Event type id: 7240904

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=7240904&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": 7240904,
  "start": "<UTC ISO 8601 start from the slots response>",
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "guests": [
    "guest@example.com"
  ],
  "bookingFieldsResponses": {
    "medewerkers": "…",
    "marketing": "…",
    "doel": "…",
    "notes": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address), `medewerkers` (Hoeveel medewerkers hebben jullie?), `marketing` (Wie doet nu jullie marketing?), `doel` (Wat wil je over zes maanden bereikt hebben?)
- 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.