# Kurzer Rückruf with Nicolas von NJ | Works

> Sie hätten lieber kurz am Telefon gesprochen? Wählen Sie eine Zeit und geben Sie Ihre Nummer an, ich rufe Sie an. 15 Minuten, kostenlos und unverbindlich.

- Host: Nicolas von NJ | Works
- Duration: 15 min
- Location: Attendee phone number
- Host time zone: Europe/Helsinki
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/njworks/rueckruf
- Event type id: 7233050

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=7233050&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": 7233050,
  "start": "<UTC ISO 8601 start from the slots response>",
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "location": {
    "type": "attendeePhone",
    "phone": "…"
  },
  "bookingFieldsResponses": {
    "Ihr-Betrieb-und-Ihre-Webseite--falls-vorhanden": "…",
    "Worum-geht-es-Ihnen": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address)
- Optional fields: `Ihr-Betrieb-und-Ihre-Webseite--falls-vorhanden` (Ihr Betrieb und Ihre Webseite (falls vorhanden)), `Worum-geht-es-Ihnen` (Worum geht es Ihnen?)
- `name` and `email` go in `attendee` and `guests` is a list of emails; every other field goes in `bookingFieldsResponses` under its name.
- `location` is required: `location.phone` is the attendee’s own.