FomoWebSocket

A Fomo add-on for On Together that exposes in-game chat as a WebSocket server, enabling real-time external integrations.

Requirements

• Fomo (hard dependency)

Features

• WebSocket chat server — Forwards all in-game chat messages and notifications to connected WebSocket clients in real time
• Bidirectional relay — Messages sent from a WebSocket client are injected into the in-game chat input; Fomo commands are supported too
• Configurable format — Separate format strings for chat messages and notifications
• Server starts automatically on launch when EnableFeature is true

In-Game Commands

Type any command into the in-game chat. Commands start with / and are not sent to other players.

• /fomowebsockettoggle (/fwst) — Toggle the WebSocket server on/off
• /fomowebsocketport [port] (/fwsp) — Get or set the WebSocket server port (default: 8765)
• /fomowebsocketmessageformat [format] (/fwsmf) — Get or set the chat message format string
• /fomowebsocketnotificationformat [format] (/fwsnf) — Get or set the notification format string

Examples

/fomowebsockettoggle
/fomowebsocketport 9000
/fomowebsocketmessageformat [{timestamp:HH:mm} {channel:short}] {username}: {message}

Configuration

Located in BepInEx/config/com.andrewlin.ontogether.fomo.websocket.cfg

• General
  • EnableFeature (default: true) — Start the WebSocket server automatically when the game launches
• WebSocket
  • WebSocketChatPort (default: 8765) — Port the WebSocket server listens on
• Formatting
  • MessageFormat (default: [{timestamp:HH:mm} {channel:short}] {username}: {message}) — Format string for chat messages sent to clients
  • NotificationFormat (default: [{timestamp:HH:mm}] {message}) — Format string for notifications sent to clients

Format Placeholders

The MessageFormat and NotificationFormat settings accept the following placeholders:

• {timestamp} — message time; accepts a C# DateTime format specifier (e.g. {timestamp:HH:mm})
• {channel} — full channel label use {channel:short} for just the first character (G / L)
• {username} — display name of the sender
• {message} — message body
• {distance} — distance in metres for local messages, empty for global/notifications
• {source} — internal message source identifier
• {playerid} — sender's player ID

Usage

1. Install Fomo and FomoWebSocket via r2modman or Thunderstore
2. Launch the game — the server starts automatically if EnableFeature is true
3. Connect any WebSocket client to ws://localhost:8765
4. Use /fomowebsockettoggle in chat to start or stop the server at runtime

Receiving messages

Each chat message arrives as a plain text string formatted according to MessageFormat. Notifications use NotificationFormat.

Sending messages

Send any plain text string to the WebSocket server. It will be injected into the in-game chat input. Fomo commands (e.g. /fomohelp) are also supported.

Installation

Use r2modman or the Thunderstore app for the simplest install. Fomo must be installed first.

Manual:

1. Install Fomo first
2. Copy AndrewLin.FomoWebSocket.dll into BepInEx/plugins/
3. Launch the game — the server starts automatically

Changelog

All notable changes to FomoWebSocket will be documented in this file.

[1.2.7] - 2026-04-12

Changed

• Dependency update to Alpha 0.0.11

[0.2.3] - 2026-03-06

Changed

• Fixed set message and notification format in-game

[0.2.2] - 2026-03-04

Changed

• Incoming WebSocket messages are now routed via ChatUtils.DispatchIncomingText: /fomo* commands are processed directly by ChatCommandManager; other slash commands are injected via the UI input system; plain text is sent through the regular chat pipeline
• TMP tag stripping now also removes <align> and <rotate> tags

[0.2.1] - 2026-03-02

Fixed

• Build configuration: corrected Directory.Build.props and .csproj to restore clean builds

[0.1.0] - 2026-03-01

Added

• Initial release as a standalone mod split from Fomo
• WebSocket server via Fleck, forwarding all chat entries and notifications in real time
• /fomowebsockettoggle (/fwst) — toggle the WebSocket server on/off
• /fomowebsocketport (/fwsp) — get or set the WebSocket server port at runtime
• /fomowebsocketmessageformat (/fwsmf) — get or set the chat message format string
• /fomowebsocketnotificationformat (/fwsnf) — get or set the notification format string
• EnableFeature config to start the server automatically on launch
• WebSocketChatPort config (default: 8765)
• MessageFormat config with named placeholders ({timestamp}, {channel}, {username}, {message}, etc.)
• NotificationFormat config for system notifications
• Bidirectional relay — incoming WebSocket messages are injected into the in-game chat on the Unity main thread