# Free 20-minute call with Daniel Deegan

> A quick, no-pressure chat about what you need. Tell me what's slowing your business down and I'll tell you honestly whether software can fix it, roughly what it would cost, and how long it would take.

- Host: Daniel Deegan
- Duration: 20 min
- Location: Cal Video
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/diagnosly/intro
- Event type id: 7656767

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=7656767&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": 7656767,
  "start": "<UTC ISO 8601 start from the slots response>",
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "guests": [
    "guest@example.com"
  ],
  "bookingFieldsResponses": {
    "what-you-need": "…",
    "website": "…",
    "notes": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address), `what-you-need` (What do you need help with?)
- Optional fields: `website` (Your website, if you have one), `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.