# New Client Booking with Justin Allen | Fullstack Design Agency

> Book a 30-minute intro call with Justin from Fullstack Design Agency.

- Host: Justin Allen | Fullstack Design Agency
- Duration: 30 min
- Location: Cal Video
- Host time zone: America/Chicago
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/fullstack-design-agency/30min
- Event type id: 6255965

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=6255965&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": 6255965,
  "start": "<UTC ISO 8601 start from the slots response>",
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "bookingFieldsResponses": {
    "What-services-are-you-looking-for": "…",
    "What-is-your-budget": "…",
    "What-is-your-website": "…",
    "Anything-else-we-should-know": "…",
    "How-did-you-hear-about-us": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address), `What-services-are-you-looking-for` (What services are you looking for?), `What-is-your-budget` (What is your budget?), `What-is-your-website` (What is your website?), `Anything-else-we-should-know` (Anything else we should know?), `How-did-you-hear-about-us` (How did you hear about us?)
- Optional fields: none
- `name` and `email` go in `attendee` and `guests` is a list of emails; every other field goes in `bookingFieldsResponses` under its name.