Rune

A modern MUD client built with Go and Lua.

Rune combines Go's performance and concurrency with Lua's flexibility for scripting. The architecture follows a kernel philosophy: Go handles I/O, memory, and concurrency while Lua handles logic, features, and presentation.

Features

Scripting:

• Aliases - Command expansion with exact match or regex patterns
• Triggers - React to server output with pattern matching and gags
• Timers - One-shot and repeating timers with named management
• Hooks - Event system for connecting to input/output pipeline
• Key Bindings - Bind keys to Lua callbacks
• Groups - Master switches to enable/disable sets of aliases/triggers/timers
• Command Chaining - kill rat;loot sends both; #3 {kill rat;loot} repeats
• Robust Scripting - Watchdog interrupts runaway scripts; failing callbacks are quarantined individually instead of taking the client down

Protocols:

• GMCP - Structured server data (vitals, room info, channels) with a scriptable rune.gmcp API and automatic Core.Hello handshake
• MCCP2 - Transparent zlib stream compression
• TLS - Encrypted connections (tls://host:port), including self-signed certs
• Modern Telnet - TTYPE/MTTS, NAWS, CHARSET (UTF-8), and MNES identification out of the box

Quality of life:

• Worlds - Named server bookmarks; /connect with no arguments opens a picker
• Session Logging - /log writes an ANSI-stripped transcript that reads like the screen
• Durable Storage - rune.store persists structured values across restarts
• Tab Completion - Word cache from server output with match cycling
• History - Zsh-style prefix-matching navigation
• Panes & Bars - Multiple output buffers with scrollback, reactive status bars

Installation

Download a binary for Linux, macOS, or Windows from the releases page, unpack it, and put rune on your PATH.

With Go installed, you can instead:

go install github.com/mmcdole/rune/cmd/rune@latest

Or build from source:

git clone https://github.com/mmcdole/rune
cd rune
go build ./cmd/rune/

Quick Start

Connect straight from your shell:

rune mud.example.com 4000           # plain telnet
rune tls://mud.example.com:4000     # TLS

Then, inside the client:

/world add example mud.example.com 4000    save a bookmark
/connect example                           connect by name (or later: rune example)
/log start                                 log the session to a file
/help                                      everything else

Coming from TinTin++ or Mudlet? See the migration guide.

Configuration

User scripts are loaded from ~/.config/rune/init.lua at startup.

Example init.lua:

-- Simple alias
rune.alias.exact("hp", "cast 'heal' self")

-- Regex alias with captures
rune.alias.regex("^kill (.+)$", "attack %1; murder %1")

-- Trigger: rewrite the line to highlight damage
rune.trigger.contains("You are hit", function(matches, ctx)
    return rune.style.red(ctx.line:clean())
end)

-- Repeating timer
rune.timer.every(60, "save", { name = "autosave" })

-- GMCP: subscribe to vitals and react to them
rune.gmcp.subscribe("Char")
rune.gmcp.on("Char.Vitals", function(data)
    if data.hp and data.maxhp and data.hp < data.maxhp * 0.25 then
        rune.echo(rune.style.red("[LOW HP] " .. data.hp .. "/" .. data.maxhp))
    end
end)

Keyboard Shortcuts

Key	Action
Up/Down	History navigation (prefix-matching)
Tab	Cycle through completions
Ctrl+R	Search history
Ctrl+T	Search aliases
/	Slash command picker
Ctrl+E	Open input in $EDITOR
PageUp/PageDown	Scroll output
Mouse wheel	Scroll output
Ctrl+C (2x)	Quit

The mouse is captured for scrolling, so select text with shift+drag (the standard terminal convention, as in tmux or htop).

Slash Commands

Command	Description
/connect [world | host port [tls|tls+insecure] | address]	Connect; no arguments opens the world picker
/disconnect	Close connection
/reconnect	Reconnect to last server (survives restarts)
/world add|remove|list	Manage world bookmarks
/worlds	List saved worlds
/log start [file]|stop|status	Log the session to a file
/load <path>	Load a Lua script
/reload	Reload all scripts
/lua <code>	Execute Lua inline
/aliases, /triggers, /timers	List registrations
/hooks, /binds, /bars	List registrations
/groups	List groups and their state
/group <name> on|off	Toggle a group
/gmcp [send <package> [json]]	GMCP status, or send a message for debugging
/raw <text>	Send without alias expansion
/echo <text>	Print locally (never sent to the server)
/test <line>	Simulate server output against your triggers
/version	Show client version
/help	Show all commands
/quit	Exit

Documentation

Full guides, cookbook recipes, and reference live at runemud.com. In-repo:

• Lua API Reference
• Migrating from TinTin++/Mudlet
• Architecture Overview

License

MIT License - see LICENSE for details.