# Discovery Call with Stefan Popadic

> Building something and need another brain on it? Let’s talk.

- Host: Stefan Popadic
- Duration: 30 min
- Location: Google Meet
- Host time zone: Asia/Saigon
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/stephn/discovery-call
- Event type id: 1300023

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=1300023&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": 1300023,
  "start": "<UTC ISO 8601 start from the slots response>",
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "bookingFieldsResponses": {
    "company": "…",
    "website_url": "…",
    "main_problem": "…",
    "timeline": "…",
    "budget": "…",
    "help_needed": "…",
    "decision_maker": "…",
    "anything_else": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address), `company` (Company / project name), `website_url` (Website URL), `main_problem` (What’s the main problem you want to solve?), `timeline` (When are you hoping to start or launch?), `budget` (What budget range are you working with?)
- Optional fields: `help_needed` (What do you need help with?), `decision_maker` (Who’s involved in making the decision?), `anything_else` (Anything else I should know before the call?)
- `name` and `email` go in `attendee` and `guests` is a list of emails; every other field goes in `bookingFieldsResponses` under its name.