# Free Audit Call with Josh Kelly | Backfill

> 20-minute call to see if Backfill is a fit. We’ll talk about the change events or delays you think you haven’t been paid for, and how the free audit works: you send 3 items, we send back submission-ready packages in 5 business days. No cost, no obligation.

- Host: Josh Kelly | Backfill
- Duration: 20 min
- Location: Google Meet
- Host time zone: America/Chicago
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/backfillrecovery/free-audit
- Event type id: 7815503

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=7815503&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": 7815503,
  "start": "<UTC ISO 8601 start from the slots response>",
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "guests": [
    "guest@example.com"
  ],
  "bookingFieldsResponses": {
    "Company-name": "…",
    "Trade": "…",
    "Number-of-employees": "…",
    "State": "…",
    "attendeePhoneNumber": "…",
    "notes": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address), `Company-name` (Company name), `Trade` (Trade), `Number-of-employees` (Number of employees), `State` (State)
- Optional fields: `attendeePhoneNumber` (Phone (in case video fails)), `notes` (What’s one change or delay you think you haven’t been paid for?), `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.