> For the complete documentation index, see [llms.txt](https://horizongames.gitbook.io/kronos-matchmaking/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://horizongames.gitbook.io/kronos-matchmaking/usage/reservations/overview.md).

# Overview

The reservation system of Kronos ensures that all players who want to join a game will have a free slot in the session at the time of connection. This is important when a group of friends want to join a game together, or when someone with a long loading time attempts to join.

## Reservations Structure

Here is a simple overview of what the reservation list look behind the scenes:

<figure><img src="https://3833329260-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfIkwZ5xO6YLccFyQBEgv%2Fuploads%2FTOyU1VoJJz5PJ5GfMRp0%2FReservations.jpg?alt=media&amp;token=853a132e-84af-414f-9bd3-664c6c102417" alt=""><figcaption></figcaption></figure>

Each reservation has an owner and a number of members. The **Reservation Owner** is the player who requested the reservation. The **Reservation Members** is a list of players who the reservation was made for (including the reservation owner).

Players who join the game solo will be the owner and the only member of the reservation, while players who join as a party will have all party members in the reservation members list. In the image above for example, you can see that "Player1" and "Player2" were in a party before they joined the game. Meanwhile "Player3" joined the game solo without a party.

## Reservation Classes

Reservations are implemented using [**Online Beacons**](https://dev.epicgames.com/documentation/en-us/unreal-engine/using-online-beacons-in-unreal-engine). Here is an overview of all the different reservation classes.

<table><thead><tr><th width="345">Class</th><th>Description</th></tr></thead><tbody><tr><td><code>KronosReservationListener</code></td><td>Beacon listening for client connections. This is essentially the server that other clients connect to. Only exists on the server.</td></tr><tr><td><code>KronosReservationHost</code></td><td>Beacon that handles reservations and incoming reservation client connections. Only exists on the server.</td></tr><tr><td><code>KronosReservationClient</code></td><td>Beacon that connects to the reservation host. It requests the reservation and awaits the response. Exists on both the server and the client.</td></tr></tbody></table>