csharp

crosschat-csharp

Cross-server chat via MQTT — C# implementation using MQTTnet. Compatible with the crosschat-python reference server and the Lua Garry's Mod implementation.

Requirements

• .NET 10 SDK
• MQTT broker (e.g. Mosquitto, EMQX)

CLI Usage

dotnet run -- --config ../config.json
dotnet run -- --config ../config.json --host 10.0.0.1
dotnet run -- --server-id myserver --host 10.0.0.1 -v

REPL Commands

> status                     Show known servers and users
> add Alice                  Add a local user
> del 1                      Remove a local user
> say 1 hello                Send chat message from user
> pm 1 eu2 2 hi              Send private message
> sendlua eu2 print('hi')    Send Lua code via OOC
> aowl_kick 76561197986413226 hmm    Kick player by SteamID64
> aowl_kick_user myserver 1 bye      Kick user by server+userid
> exit                       Shutdown

Files

File	Purpose
CrossChat.cs	Main host: config, MQTT lifecycle, message routing, REPL
State.cs	CrossChatState: server/user management, OOC, publish
Models.cs	Data models: CrossChatUser, CrossChatServer, BurstFlag, ICrossChatHandler
Aowl.cs	Remote admin actions: kick/ban/slap

ICrossChatHandler

Implement this interface to receive events from the CrossChat host:

public interface ICrossChatHandler
{
    Task OnUser(CrossChatUser user, string cmd, BurstFlag burst = BurstFlag.None);
    Task OnSay(CrossChatUser user, string say);
    Task OnPm(CrossChatUser sender, string targetServerId, int targetUserId, string say);
    Task OnServerAdd(CrossChatServer server);
    Task OnServerDel(CrossChatServer server);
    Task OnServerStatus(CrossChatServer server);
}

Pass it to the CrossChatHost constructor:

var handler = new MyHandler();
var host = new CrossChatHost(config: "config.json", handler: handler);
await host.RunAsync();

Aowl — Remote Admin Actions

The static Aowl class provides cross-server kick/ban/slap. Messages are broadcast to all online servers. Two targeting modes:

By SteamID64 (broadcast — all GMod servers act)

await Aowl.Kick(state, "76561197986413226", "spam");
await Aowl.Ban(state, "76561197986413226", "griefing");
await Aowl.Slap(state, "76561197986413226", "being annoying");

By server_id + user_id (targeted — only matching server acts)

await Aowl.KickUser(state, "myserver", 1, "spam");
await Aowl.BanUser(state, "myserver", 1, "griefing");
await Aowl.SlapUser(state, "myserver", 1, "being annoying");

Receiving

The host automatically subscribes to aowl_kick/ban/slap OOC types:

• aowl_kick / aowl_ban with user_id → calls State.DelUser(userId) then handler.OnUser(user, "del")
• aowl_slap with user_id → broadcasts say with text "ow" then handler.OnSay(user, "ow")

CrossChatState API

Method	Description
state.AddUser(name, extra?)	Add a local user and broadcast to all servers
state.DelUser(userId)	Remove a local user and broadcast removal
state.SendOoc(targetSid, oocName, payload)	Send an OOC message to another server
state.SubscribeOoc(oocName, callback)	Register for incoming OOC messages
state.Publish(topic, payload, qos=2, retain=false)	Publish to MQTT
state.SetState(key, value)	Publish retained dynamic state
state.FormatStatus()	Get formatted server/user status string

Configuration

{
    "mqtt": { "host": "10.0.0.1", "port": 1883 },
    "server_id": "metatest1",
    "meta": { "link": "steam://connect/..." }
}

Key	Description
mqtt.host / mqtt.port	MQTT broker address
server_id	Unique server ID
topic_prefix	MQTT topic prefix (default crosschat/)
meta	Arbitrary metadata (published as retained /meta state)