# (15 min call) Share your thoughts & opinions about forums + try prototype with Elton Lin

> I hope you can talk about your experience using internet resources like MathDash's Discord for the first 10 minutes, and also give me some honest feedback on the latest prototype of explanations.app - if you think it could become something that really benefits you :^)

- Host: Elton Lin
- Duration: 15 min
- Location: Cal Video
- Host time zone: Asia/Tokyo
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/eltonlin1998/15min
- Event type id: 654030

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=654030&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": 654030,
  "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.