# App Development Call <•> with Flutter Deviser

> Let's discuss your app idea, requirements, features, timeline, and budget. Whether you're building an MVP, scaling an existing product, or need Flutter expertise, this call will help define the next steps for your project.

- Host: Flutter Deviser
- Duration: 15 min
- Location: Google Meet
- Host time zone: Asia/Calcutta
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/flutter-deviser/app-development
- Event type id: 5983193

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=5983193&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": 5983193,
  "start": "<UTC ISO 8601 start from the slots response>",
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "guests": [
    "guest@example.com"
  ],
  "bookingFieldsResponses": {
    "attendeePhoneNumber": "…",
    "notes": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address), `attendeePhoneNumber` (Phone number), `notes` (Additional notes)
- 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.