GrrrLCU

GrrrLCU is a wrapper for the LCU API which is unofficially provided by Riot Games.

This library is currently compatible with .NET 8 and higher for Windows.

Contributors

Usage

Installation

Grrr, GRRR. x3

dotnet install BlossomiShymae.GrrrLCU

Sample application

A demonstration of GrrrLCU with more code examples can be found here.

To run the demo, clone the repo and then do:

dotnet run --project BlossomiShymae.GrrrLCU.Demo

Requesting the LCU

This library uses the System.Net.Http.HttpClient interface via LcuHttpClient. It comes with a built-in handler that takes care of the request path and authorization header.

Note

The built-in handler will attempt to refresh the port and auth if a HttpRequestException is encountered on request. InvalidOperationException will be thrown if the port of the current LCU process cannot be found or the port cannot be connected to.

Getting the LcuHttpClient instance

var client = Connector.GetLcuHttpClientInstance();

General request

var response = await client.SendAsync(new(HttpMethod.Get, "/lol-summoner/v1/current-summoner"));

var me = await response.Content.ReadFromJsonAsync<Summoner>();

GET request

var me = await client.GetFromJsonAsync<Summoner>("/lol-summoner/v1/current-summoner");

POST request with JSON body

var response = await client.PostAsJsonAsync("/player-notifications/v1/notifications", playerNotificationResource);

var resource = await response.Content.ReadFromJsonAsync<PlayerNotificationResource>();

Warning

ProcessFinder.IsActive() does not necessarily mean that the LCU process port is open for requests. Use ProcessFinder.IsPortOpen() instead.

Utilities

var leagueClientProcess = ProcessFinder.GetProcess();
var processInfo = ProcessFinder.GetProcessInfo();
var isActive = ProcessFinder.IsActive();
var isPortOpen = ProcessFinder.IsPortOpen();

var riotAuthentication = new RiotAuthentication(processInfo.RemotingAuthToken);

WebSockets

This library uses the Websocket.Client wrapper.

Create a client:

var client = Connector.CreateLcuWebsocketClient();

Listen to events, disconnections, or reconnection messages:

using System; // Include to avoid compiler errors CS1503, CS1660.
              // You may or may not need this.

client.EventReceived.Subscribe(msg =>
{
    Console.WriteLine(msg?.Data?.Uri);
});
client.DisconnectionHappened.Subscribe(msg => 
{
    if (msg.Exception != null) throw msg.Exception;
});
client.ReconnectionHappened.Subscribe(msg =>
{
    Console.WriteLine(msg.Type);
});

Use it:

// This starts the client in a background thread. You will need an event loop
// to listen to messages.
await client.Start();

// Subscribe to every event that the League Client sends.
var message = new EventMessage(EventRequestType.Subscribe, EventKinds.OnJsonApiEvent);
client.Send(message);

// We will need an event loop for the background thread to process.
while(true) await Task.Delay(TimeSpan.FromSeconds(1));

Warning

Whenever a public application is made with GrrrLCU, graceful reconnection is needed as the end-user may restart, exit, or open the League client. The built-in reconnection handler will not be enough for this case.

An example pattern using threads is provided to show how reconnection can be done.

public class ExampleViewModel
{
	public WebsocketClient? Client { get; set; }

	public ExampleViewModel()
	{
		new Thread(InitializeWebsocket) { IsBackground = true }.Start();
	}

	private void InitializeWebsocket()
	{
		while (true)
		{
			try
			{
				var client = Connector.CreateLcuWebsocketClient();
				client.DisconnectionHappened.Subscribe(OnDisconnection);

				client.Start();
				client.Send(new EventMessage(EventRequestType.Subscribe, EventKinds.OnJsonApiEvent));
				Client = client;
				return;
			}
			catch (Exception) { }
			Thread.Sleep(TimeSpan.FromSeconds(5));
		}
	}

	private void OnDisconnection(DisconnectionInfo info)
	{
		Client?.Dispose();
		new Thread(InitializeWebsocket) { IsBackground = true }.Start();
	}
}