# Free constraint check with Jamie O'Connell

> Fifteen minutes on a call. You tell us how your business runs and where the days go. We tell you what we'd fix first and roughly what it would cost. You leave knowing your bottleneck, whether or not we ever work together.

- Host: Jamie O'Connell
- Duration: 15 min
- Location: Cal Video
- Host time zone: America/Los_Angeles
- Confirmation: The host confirms each booking; it stays pending until they accept it.
- Booking page: https://cal.com/616jamie/constraint-check
- Event type id: 6241121

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=6241121&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": 6241121,
  "start": "<UTC ISO 8601 start from the slots response>",
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "guests": [
    "guest@example.com"
  ],
  "bookingFieldsResponses": {
    "time-sink": "…",
    "notes": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address)
- Optional fields: `time-sink` (What's eating most of your time?), `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.
- A successful response is a pending booking request.