# Supermessage Product Demo with Jayesh Gopalan

> See how Supermessage helps you run WhatsApp campaigns and manage customer conversations using the official WhatsApp Cloud API. We’ll discuss your use case, show you the product, and answer your questions.

- Host: Jayesh Gopalan
- Duration: 30 min
- Location: Google Meet
- Host time zone: Asia/Calcutta
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/jayeshg/supermessagedemo
- Event type id: 6733486

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=6733486&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": 6733486,
  "start": "<UTC ISO 8601 start from the slots response>",
  "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.