miod

Important

Only tested on macOS. Not sure yet how it behaves on Linux or Windows.

I'm an engineer, but these days I solve the boring problems entirely by vibe coding. Somewhere along the way I felt I had lost the creativity and curiosity I used to have when writing code myself.

So I started thinking about how to make vibe coding fun again. miod is the first try: while the agent does the work, you get to hear it think, read, edit, fail and fix, with a little piece of music no one has heard before.

Feel free to add more moods, flavours and styles. Each mood is one row in hooks/moods.ts, each flavour one row in hooks/flavours.ts, each sound style one entry in hooks/styles.ts, and each wave look one file in hooks/waves/.

Feeling it's a bit too noisy? 🙉 No hard feelings. Just turn it off with /miod off.

What it is

A Claude Code mod (MIDI + mod) that writes music on the spot while Claude works. No music files, no library, no AI model.

• Every task picks its own flavour (lo-fi, chiptune, ambient, jazzy and 8 more), key, chord progression, tempo, sound and theme.
• The mood follows what the agent is doing, and the mood picks the scale (16 of them) from its own weighted list: failing leans on minor and harmonic minor, shipping on mixolydian and major. Every mood has 10 variants, and a new variant and scale are picked as the task goes: whenever the activity changes, and every 4 phrases. The task's flavour bends it too, so editing in a lo-fi task sounds nothing like editing in a chiptune one.
• The faster it spends tokens, the busier the music.
• Above the prompt, one line shows the mood, flavour, key, tempo and energy, with a wave under it that scrolls with the music, coloured by mood:

• Tasks flow into each other: the next task fades in, in a related key. If no new task comes, a closing chord fades out at the end of the phrase.

Install

Needs Claude Code 2.1.290 or newer, on macOS.

claude plugin marketplace add delexw/miod
claude plugin install miod@miod

Then start a new session.

Usage

/miod        is it on or off?
/miod off    stop the music
/miod on     play again from the next task
/miod wave   list the wave looks: bars, line, mirror, dots, pulse
/miod wave dots   switch the wave to the dots look

How the mood is picked

Each row shows the mood's first variant and its most likely scale. The variants are in MOODS and the scale weights in MOOD_SCALES, both in hooks/moods.ts.

The agent is…	When it uses…	Sounds
thinking	no tool	calm
reading	Read, Grep, Glob, MCP tools	airy
exploring	WebSearch, WebFetch	curious (lydian)
planning	TodoWrite, plan mode	hopeful (major pentatonic)
asking	AskUserQuestion	waiting, almost silent
editing	Edit, Write	bright (major)
running	Bash	driving beat
installing	npm, bun, pip, brew… install	patient (minor pentatonic)
testing	test, check, lint, tsc	focused (dorian), busy beat
shipping	git commit, push, merge, gh pr	triumphant (mixolydian)
deleting	rm -r, git reset --hard, git clean	ominous (phrygian), low drone
delegating	Agent	one harmony voice per subagent
failing	a Bash command that failed	tense (minor), until a command passes

When several happen in one 8-beat phrase, the one higher in STRONGEST_FIRST (hooks/activity.ts) wins. A filling context window lifts the melody and, past 80%, adds a low drone.

The scales follow how musicians describe each mode (musical-u, Jiang et al. 2024).

Add a mood or style

• Mood variant: add a row to that mood's list in MOODS in hooks/moods.ts.
• New mood: add the name to Activity and STRONGEST_FIRST in hooks/activity.ts, map tools or commands to it there, give it a list of at least 10 variants in MOODS and a row of scale weights in MOOD_SCALES.
• Flavour: add a row to FLAVOURS in hooks/flavours.ts. Each field nudges every mood: brighter or darker scale, busier or calmer, drums up or down, swing, bass line.
• Scale: add it to SCALES in hooks/theory.ts, then give it a weight in at least one mood's MOOD_SCALES row. A test fails if a scale belongs to no mood.
• Chords: add to PROGRESSIONS in hooks/theory.ts.
• Wave look: add a file to hooks/waves/ that exports a WaveLook (how many rows, and a draw function), then list it in WAVES in hooks/waves/index.ts.
• Style: add a wave function to STYLES in hooks/styles.ts. It must return values between -1 and 1.

Then check it:

claude plugin validate .
claude plugin test .

Run a checkout without installing it with claude --plugin-dir <path to this repo>.

Limitations

• Only tested on macOS, where Claude Code plays the audio through afplay.
• The sound is simple chiptune-style tones.
• miod only hears the session it's loaded in.