# Free intro call with Martin Lorenz · Reventless

> We get to know each other and talk about one process in your business that costs you time or nerves today. Together we find out whether an app of your own is worth it for that process, and what the next step would be. A few questions help us prepare. The call runs on kMeet, a Swiss video service, in your browser. No account or installation needed.

- Host: Martin Lorenz · Reventless
- Duration: 30 min
- Location: Link meeting
- Host time zone: Europe/Vienna
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/reventless/intro
- Event type id: 7766716

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=7766716&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": 7766716,
  "start": "<UTC ISO 8601 start from the slots response>",
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "bookingFieldsResponses": {
    "business": "…",
    "process": "…",
    "people": "…",
    "notes": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address), `business` (What does your business do?), `process` (Which process costs you the most time or nerves?), `people` (How many people work in it?)
- Optional fields: `notes` (Anything else?)
- `name` and `email` go in `attendee` and `guests` is a list of emails; every other field goes in `bookingFieldsResponses` under its name.