SharpMUTerm

A MU* client for MUSH, MUCK and MUD players, in your terminal or in a window of its own.
Windows and Linux · .NET 10 · MIT licensed

SharpMUTerm is one client with two front ends. sharpmuterm runs inside a terminal (kitty, WezTerm, Ghostty, Windows Terminal and others). sharpmuterm-window is the same client in a desktop window, with native menus, dialogs, a map, gauges and settings drawn by Avalonia. Both read the same configuration, take the same keys and connect to any world that speaks telnet.

Status: early, and moving quickly. Each release's changes are in CHANGELOG.md; the architecture and roadmap are in docs/PLAN.md.

Install

Download a package from the latest release. Each one holds both programs, and none needs a .NET runtime.

Platform	Package	What to run
Windows	SharpMUTerm-win-Setup.exe	Start menu ▸ SharpMUTerm opens the window, and sharpmuterm runs from any terminal. Installs per user, with no administrator prompt.
Windows	SharpMUTerm-win-Portable.zip	Unzip and run SharpMUTerm.exe for the window, or current\sharpmuterm.exe.
Linux	SharpMUTerm.AppImage	chmod +x it and run it to open the window. Put --terminal first to run the terminal client instead.
Linux	sharpmuterm-linux-x64.tar.gz	Unpack and run either program. This copy does not update itself.

The installed Windows copy, the portable one and the AppImage update themselves: they check GitHub for a newer release half a minute after start and once a day (F7 ▸ check for updates), say so when there is one, and download it and restart into it when you choose Update. Ctrl+P ▸ Check for updates asks at any time. See docs/UPDATES.md.

sharpmuterm                      # open with no connection; the welcome helps you add a world
sharpmuterm example.org 4000     # connect straight away (add --tls for TLS)
sharpmuterm --window             # the same, in the desktop window
sharpmuterm --help               # every option, the files it keeps, and the keys

macOS is not packaged yet.

Terminal or window

	Terminal (sharpmuterm)	Window (sharpmuterm-window)
Drawn by	SharpConsoleUI, in character cells	The same cells drawn with Skia, plus native Avalonia views over them
Pictures from a world	Kitty graphics in kitty, Ghostty and Rio; half-blocks elsewhere, with a Sixel overlay in Windows Terminal	Real bitmaps on every platform
Settings, palette, search, composer	Cell screens and pop-ups	Native windows, cards and editors built from the same models
Panels	Cell panes	Native map, gauges, who-here list and quick bar, which can pop out into their own windows
Newline in the command line	⌥⏎	⌃⏎ or ⇧⏎ (⌥⏎ maximises)
Fonts	Your terminal's; a Nerd Font for the header and sidebar icons	Inter and JetBrains Mono bundled, icons included

Everything a player can do is reachable in both. The two front ends share one application and one set of view models (SharpMUTerm.Client), and the test suites draw every screen through both and compare them cell for cell, so a feature cannot land in one and not the other.

What it does

Connecting

• TCP with TLS and IPv6. Worlds hold characters, each with an optional saved login; passwords go to the system's credential store (Windows Credential Manager, the Secret Service keyring, the macOS Keychain), with an owner-only file only as the fallback.
• Browse public worlds from mu*index and connect from the listing. telnet:// and telnets:// links open in the client.
• Automatic reconnect after a dropped connection (never after you quit), per world.
• Import worlds, characters and automation from MUSHclient, Mudlet and TinTin++. Nothing is written until you accept the review.

Protocols

• Telnet negotiation through TelnetNegotiationCore: NAWS (each pane reports its own size), TTYPE/MTTS, NEW-ENVIRON (MNES), CHARSET, EOR and GA prompts, MCCP, GMCP, MSDP, MSSP, MSP and MCP 2.1.
• ANSI colour in 16, 256 and 24-bit. MXP with its line-security model, custom elements and entities, clickable <SEND> links and menus, and inline <IMAGE>s. Pueblo, negotiated as servers announce it.
• GMCP and MSDP data feeds meters, the vitals panel, who is in the room, channel windows, Lua and a data viewer. GMCP Char.Login, Client.Media (MCMP sound), External.Discord presence and Comm.Channel are supported.
• MSSP reports are kept per server and shown on the world's info page.
• MOO verb and property editing over MCP simpleedit, in the composer.

Reading

• Split panes with tabs, spawn windows that triggers route lines into, and capture of GMCP channels into windows of their own. Layouts (Roleplay, Combat, or your own) arrange them per world or character.
• Scrolling back splits the pane, so new lines keep arriving underneath. Freeze a pane, search what it holds (⌃F, plain or regex, one window or all) and search older history (⌥H).
• Markers for where you stopped reading, in a window you were not watching and in the terminal you left.
• Panes come back after a restart with their last lines. Optional joining of lines the server hard-wrapped, highlighted names, timestamps, links detected in plain text, emoji substitution.
• Themes (Dark, Light, Solarized Dark) with a contrast floor applied to every colour the client paints, and a colour per character for their panes and command line.

Writing

• A command line that grows as you type, with undo, selection, per-window drafts, per-character history (⌃R searches it), word completion from the room and the output, and optional command stacking.
• F1 opens a full-screen composer for long posts: line breaks are sent as %r, with a literal mode that escapes MUSH code, a preview of what will be sent and spell checking (Hunspell dictionaries, downloaded on request).
• A send group sends one line to several characters. A MUSH edit grab lands on the command line, never sent.

Automation and scripting

• Triggers (regex, wildcard, starts with, contains) that gag, highlight, rewrite, respond, route or run a script, built from a selection in the output with a live test against recent lines. Aliases, key bindings, timers, all held in named trigger sets shared between characters.
• Sandboxed Lua 5.2 through MoonSharp: world, output, trigger, alias, timer, gmcp, msdp, map, store and more, with an in-app editor and a console per character.
• Packages: a zip of trigger sets, scripts and sound that installs after a review of what it can do as you.

Maps and panels

• An automapper fed by GMCP room data or text patterns, with areas, levels, hand editing and undo, and speedwalking that waits for each room to arrive.
• Panels for vitals, who is here, a quick bar of key bindings and a docked composer.

Sound and alerts

• MCMP and MSP sound through SoundFlow, with captions when there is no audio device.
• Desktop alerts when you are paged or named while away, and a list of recent alerts.

Accessibility

• --plain runs the client as plain lines on stdin and stdout for screen readers. The window has live regions for output and notices, and every native control is named and reachable by Tab.

Logs

• Plain-text and HTML session logs, and scene logs that keep only the poses.

Keys

Key	Does
⌃P	Command palette: every action, searchable
F1	Composer
F2–F10	Triggers, aliases, keys, worlds and characters, timers, text and display, input, characters, packages
⌃F / ⌥H	Search the panes / search older history
⌃R	Search command history
⌥1–⌥9	Go to a numbered window (the sidebar shows the numbers)
⌥J / ⌥K	Next or previous character
⌃N / ⌃O	Next tab / next pane
⌃B	Pane keys: split, close, zoom, move, resize
⌥M	Layouts
⌥F	Freeze the pane
⌥R / ⌥D	Reconnect / disconnect
⌃Q	Quit (asks first)

/help in the client lists every key, slash command and how-to. F4 says which keys the client already uses and which ones your terminal can deliver.

Building

Requires the .NET 10 SDK.

dotnet build SharpMUTerm.slnx -c Release
dotnet run -c Release --project src/SharpMUTerm.Tui -- <host> <port>        # terminal
dotnet run -c Release --project src/SharpMUTerm.Avalonia -- <host> <port>   # window
dotnet run -c Release --project src/SharpMUTerm.Avalonia -- --demo-config   # demo worlds, saves nothing

Testing

The suites use TUnit on Microsoft.Testing.Platform, so run each project directly (dotnet test does not run them on .NET 10):

for suite in Core Client Graphics Scripting Web Tui Avalonia; do
  dotnet run -c Release --project tests/SharpMUTerm.$suite.Tests </dev/null
done

The terminal client renders frames headlessly for checking layout without a terminal; see docs/SCREENSHOTS.md.

Projects

Project	What it holds
SharpMUTerm.Core	Transport, telnet, ANSI/MXP/Pueblo parsers, GMCP/MSDP data, scrollback, triggers, aliases, macros, timers, maps, media queue, packages, import, configuration and logging. No UI.
SharpMUTerm.Client	What both front ends draw: the command registry, palette ranking, settings declarations, help and the view models for every surface. References Core only.
SharpMUTerm.Graphics	Kitty and Sixel encoders, half-block fallback, terminal capability probe, image policy
SharpMUTerm.Scripting	The MoonSharp Lua host and its API
SharpMUTerm.Audio	The sound device (SoundFlow, NVorbis)
SharpMUTerm.Web	The built-in text web view
SharpMUTerm.Tui	The application on SharpConsoleUI, and sharpmuterm
SharpMUTerm.Avalonia	sharpmuterm-window: a console driver drawn with Skia, and the native views
tests/*	Seven TUnit suites, one per project above except Audio

Libraries

Library	Used for	Licence
SharpConsoleUI	Compositor, layouts, tabs, markup and Kitty graphics in the terminal	MIT
Avalonia (with Skia)	The desktop window and its native views	MIT
TelnetNegotiationCore	Telnet option negotiation, GMCP, MSDP, MSSP, MCCP, MCP	Apache 2.0
MoonSharp	Sandboxed Lua scripting	BSD 3-Clause
SoundFlow and NVorbis	Sound playback and OGG Vorbis decoding	MIT
WeCantSpell.Hunspell	Spell checking in the composer	MPL 1.1 / GPL 2.0 / LGPL 2.1
AngleSharp	HTML parsing for the web view	MIT
SixLabors.ImageSharp	WebP decoding	Six Labors Split (Apache 2.0 for open source)
Serilog	The client's own diagnostics log	Apache 2.0
MinVer	Version numbers from git tags (build only)	Apache 2.0
TUnit	Tests	MIT

The window bundles Inter, JetBrains Mono and Symbols Nerd Font Mono, all under the SIL Open Font License.

More

• docs/PACKAGING.md and docs/RELEASING.md: how the packages and releases are made.
• CLAUDE.md: the design decisions behind each feature, in detail.

License

MIT © 2026 Harry Cordewener