> ## Documentation Index
> Fetch the complete documentation index at: https://docs.guile.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Appointment Slot Unavailable

> The requested appointment slot is no longer available

## Cause

Another booking took this slot between the availability check and the commit, so
the slot is no longer free.

## Fix

[List appointment openings](/api-reference/appointments/list-appointment-openings)
again and offer the caller the next open slot. Do not retry the same
`startsAt` until availability shows it free.

## Retry safety

Not retryable

## Raised by

These operations can return this problem:

* [Create an appointment](/api-reference/appointments/create-an-appointment)
* [Create an appointment as a barber](/api-reference/appointments/create-an-appointment-as-a-barber)

## Example

```json theme={null}
{
  "type": "https://docs.guile.app/problems/appointmentSlotUnavailable",
  "title": "Appointment Slot Unavailable",
  "status": 409,
  "detail": "The 10:30 slot with Marcus is no longer free."
}
```