miditui

Crates.io

An interactive terminal app/UI for MIDI composing, mixing, and playback—written in Rust.

miditui allows for a DAW-like experience in the terminal and has many features that you wouldn't expect a terminal app to have:

• Full terminal mouse support: click, drag, scroll, double-click, right-click all work, which allows you to pan views, select notes, click piano keys to play them
• A piano roll view for showing the notes as they are played in the song
• An Insert mode to press keys on your keyboard (or simply click the piano roll) and create music in real time: Two-octave QWERTY layout (Z-M and Q-I rows) with live audio playback as you type
• A project timeline view to see all the MIDI tracks with active notes at the timestep
• Low-latency 44.1kHz audio via rustysynth
• Timeline seeking by clicking the time rulers to skip to any point of the track
• Unlimited MIDI tracks with per-track mute/solo, volume/pan (L/R) controls, and automatic MIDI channel assignment
• Autosave that periodically saves your project and automatically reloads it when restarting the app
• Undo/Redo support to avoid losing work
• Import/Export MIDI and JSON files, plus export the music as a WAV file.

Watch this video to see miditui in action (enable sound within the in-line player on the top-right):

miditui.mp4

Disclosure: This crate was developed with the assistance of Claude Opus 4.5, initially as a personal experiment just to see how well modern coding agents can handle TUIs and I figured a full-on MIDI mixer which has atypical UI requirements would be a more interesting test. Opus 4.5 did a good job and after a demo went viral on X people were asking for me to release it, so I decided to spend extra time polishing and comprehensively testing the app before then open-sourcing it. I have written a full analysis of the agentic coding workflow—including the prompts provided to Opus 4.5—in the agent_notes folder.

Installation

The app binaries can be downloaded from the Releases page for your platform of choice, or by using the following terminal commands:

# macOS Apple Silicon
curl -sL https://github.com/minimaxir/miditui/releases/latest/download/miditui-macos-arm.tar.gz | tar xz

# macOS Intel
curl -sL https://github.com/minimaxir/miditui/releases/latest/download/miditui-macos-intel.tar.gz | tar xz

# Linux ARM64
curl -sL https://github.com/minimaxir/miditui/releases/latest/download/miditui-linux-arm64.tar.gz | tar xz

# Linux x64
curl -sL https://github.com/minimaxir/miditui/releases/latest/download/miditui-linux.tar.gz | tar xz

For Windows, download and unzip the binary from here.

If Rust is installed, you can install the crate directly via cargo:

cargo install miditui

Additionally, a SoundFont file (.sf2) is required to run miditui. There are many free SoundFonts which are commercially friendly for music generation: a small one is TimGM6mb.sf2 (6 MB, direct download link), while a more robust SoundFont is GeneralUser GS (32.3 MB, via the "GeneralUser GS 2.0.2 w/ documentation rev. 4" link).

It is also strongly recommended to use a terminal that support horizontal mouse scrolling which not all do: I recommend Ghostty.

Example Usage

To run miditui: if you downloaded the binary, run it in the terminal with ./miditui. If you installed via Rust, run cargo run. On the first load, the app will prompt you to select the path to a SoundFont: the path to the SoundFont will be saved for future runs.

miditui opens in Normal Mode, with a combined Piano Roll and Project Timeline view. In this mode, you can move the cursor with the arrow keys and press Enter to insert notes, or you can double click where you want to insert the note, or even drag-and-drop notes. This mode also allows for the most keyboard shortcuts, such as g to cycle between views.

To play your composition, press Space. You can click the time ruler to seek to a specific point and . to reset to the start.

Insert Mode, entered by pressing i or right-clicking, allows inserting notes with less friction and playing back notes in real time as if the keyboard was a piano. Single-clicking areas on the piano roll immediately inserts notes, and playing multiple notes on the keyboard at the same time also works.

With a Track selected, you can press a to add a track, m to mute a track, or s to play the track as a solo.

You can save your project to a JSON/MIDI file with Ctrl+S or export it as an uncompressed .wav file with e.

There are a very large number of keyboard shortcuts that are too big to fit into the README: press ? in the app for documentation. Experimentation is encouraged, and if you break something, Ctrl+Z to Undo!

If you want example MIDIs for testing and opening them with Ctrl+O, you can view the /examples folder.

Notes

• Due to variations in terminal support, key release events cannot be reliably detected, which means the piano-key-input intentionally does not support holding keys to extend notes, unfortunately.
• Music files are autosaved as a bespoke .oxm binary file, which essentially wraps the song metadata with a few added fields outside of the MIDI spec, such as the SoundFont path and the mute/solo status of each track.
• All colors within miditui are based on your defined terminal colors. The Ghostty terminal theme used in the example image/video is by David Crespo and is available here, although the examples use the Jetbrains Mono fontface instead.
• The music file played in the demo video is Dance.mid by S. Christian Collins, located here with other demo MIDIs.

License

MIT