LCU - The League Client

The LCU, which stands for “League Client Update” is the League Client. You use parts of the LCU for your projects.

This page contains up-to-date information for which endpoints you are allowed to use.

It’s important that you create an application on the dev portal telling Riot how you are using the LCU in your project. The more information they have about how people are using the LCU, the better feedback they can give to other teams at Riot.

The LCU must be running on your computer, and you must be logged in, in order to use the LCU endpoints.

Rift Explorer

Pupix on Discord created an excellent app called Rift Explorer to explore the LCU endpoints. You can download it here.

Vivi on Discord created a website that allows you to view the swagger for the LCU endpoints online.

LCU Explorer

LCU Explorer is a Rift Explorer alternative created by Hi-Ray and MingweiSamuel. You can download it here

Tips

Starting the LCU with the flag --mode unattended will allow you to use some of the LCU endpoints without logging in. This is convenient for running the LCU on a headless (no-monitor) server.

You can create a normal game mode lobby by passing the queue ID ({"queueId":430}) to the /lol-lobby/v2/ POST endpoint.

To create a custom game lobby, use the below POST request. Change PRACTICETOOL to CLASSIC if you don’t want it to be a practice game.

POST
/lol-lobby/v2/lobby
{
  "customGameLobby": {
    "configuration": {
      "gameMode": "PRACTICETOOL", "gameMutator": "", "gameServerRegion": "", "mapId": 11, "mutators": {"id": 1}, "spectatorPolicy": "AllAllowed", "teamSize": 5
    },
    "lobbyName": "Name",
    "lobbyPassword": null
  },
  "isCustom": true
}

These flags are useful: --app-port=1337 --headless --allow-multiple-clients.

If you are running on Linux with Wine, you need to set the Wine prefix to Windows XP and have wine-staging for compatibility with the anti cheat.