# Intro call with Peter Rochel – JTBD project with Peter Rochel

> You're facing a decision – positioning, product, market entry – and the data you have won't carry it. In 15 or 30 minutes we'll work out whether your problem is an evidence problem and what it would take to solve it. No pitch: if JTBD isn't the right lever, I'll tell you. Bring the decision you're facing and the date it has to be made by.

- Host: Peter Rochel
- Duration: 15, 30 min
- Location: Zoom Video, Cal Video, MS Teams
- Host time zone: Europe/Berlin
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/peterrochel/intro-call-with-peter-rochel-jtbd-project
- Event type id: 6644609

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=6644609&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": 6644609,
  "start": "<UTC ISO 8601 start from the slots response>",
  "lengthInMinutes": 15,
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "guests": [
    "guest@example.com"
  ],
  "bookingFieldsResponses": {
    "herkunft": "…",
    "empfohlen-von": "…",
    "notes": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address), `herkunft` (What prompted this appointment?)
- Optional fields: `empfohlen-von` (If a recommendation or something else: by whom or through what?), `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.
- `location` is optional; without it the booking uses the event’s first location.
- `lengthInMinutes` picks one of 15, 30; pass the same value to the slots request as `duration`.