Coupler

A dedicated client for CoffeeMUD, and for nothing else. Coupler is built to be the most immersive way to play CoffeeMUD, for every player, sighted or not: a game you hear as well as read, in sounds, voices and words, played on the screen, through a screen reader or with your eyes closed.

Named for the acoustic coupler, the cradle a phone handset sat in to carry a modem's data. Part of the ansiapps family. Free and open source under the Apache License 2.0.

Coupler is in development. It runs on macOS first; other platforms come later.

What it does

• Three ways to play. Terminal (the game's own screen, 80 columns), Immersive (sound first and self-voiced: cues, a narrator, a voice for every character) and Workshop (everything at once, arranged your way).
• Accessible first. Everything works from the keyboard and with VoiceOver. A picture always has the same facts in words beside it. Speech is kept short: what can be a sound is one. Review mode, sound captions, readable colors and big text are built in.
• Hears the game. CoffeeMUD's GMCP and MSDP: vitals, fights, who's talking and where you are, said or played rather than read off the screen.
• An auto-mapper from the game's room data, with directions in words and walking a route one step at a time.
• Hooks and assets. Sounds, music, background ambience and ANSI art on anything the game reports. Coupler's own synthesizer plays MIDI without a SoundFont, and it can compose music and paint pictures from your words, all on your computer.
• Room pictures drawn in ANSI by Coupler's own painter.
• A journal of everything said to you, kept on your computer.

Coupler talks to CoffeeMUD and to nothing else: no accounts, no telemetry, no server of ours. Nothing about you or your play leaves your computer except what you send the game. The one exception is yours to turn on: checking for updates (gear menu) asks GitHub which Coupler release is the latest, sending nothing but Coupler's version.

Building

You need Node.js, Rust (stable), CMake, and on macOS the Xcode command line tools.

npm install
scripts/pocket-tts-fetch.py      # once: the bundled voices' model, ~250 MB
scripts/coffeemud-sf2-fetch.py   # once: CoffeeMUD's sounds, 77 MB
npm run tauri dev                # a dev build (Vite on port 1460)
scripts/build-release.sh --bundles app   # a release Coupler.app

Always build releases with scripts/build-release.sh: it keeps your machine's paths out of the app, and on a Mac builds it universal, signed and notarized. Signing needs an Apple Developer ID (the script's header says how to set it up); COUPLER_UNSIGNED=1 builds without one, for your own Mac only.

The web build (npm run build:web) is a slimmer Coupler that runs in a browser.

Tests: cargo test --manifest-path src-tauri/Cargo.toml, cargo clippy --manifest-path src-tauri/Cargo.toml --all-targets and npx tsc --noEmit.

Contributing

See CONTRIBUTING.md. Security problems: SECURITY.md. CLAUDE.md is the full set of operating rules, written for Claude Code and for anyone working on Coupler.

License

Apache License 2.0: see LICENSE and NOTICE. Every third-party license Coupler ships is in the app, under About → Open-Source Licenses.

Coupler's protocol handling follows Sip, CoffeeMUD's own client by Bo Zimmerman. CoffeeMUD is by Bo Zimmerman and its contributors.