# Free 15-Min AI Assessmentl with Mauro Castillo, MD.

> 15 minutes. No pitch. No pressure. Tell me where you're losing time in your business and I'll show you exactly what AI can automate — and what the impact looks like in hours and dollars. You'll leave the call with: — A clear picture of where AI fits in your business — The 1-2 systems that would save you the most time — Honest answer on whether it's worth doing No sales calls after. No spam. Just clarity.

- Host: Mauro Castillo, MD.
- Duration: 15 min
- Location: Cal Video
- Host time zone: America/New_York
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/mauro-castillo-md/15min
- Event type id: 5641916

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=5641916&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": 5641916,
  "start": "<UTC ISO 8601 start from the slots response>",
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "guests": [
    "guest@example.com"
  ],
  "bookingFieldsResponses": {
    "title": "…",
    "notes": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address), `title` (What's your business?), `notes` (What's eating most of your time right now?)
- Optional fields: `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.