Make audio instruments, effects and MIDI tools, and play them everywhere.

Maru turns a musical idea into something people can actually play: a plugin in their DAW, an instrument in the browser, or a device on their desk.

• Hear every change right away. Tweak a sound and listen instantly, with no rebuild-and-reload loop breaking your flow.
• One project, every platform. The same instrument or effect runs as a VST3, Audio Unit or CLAP plugin, in the browser, and on hardware such as Daisy Seed and ESP32-S3 (beta).
• Works with your coding agent. Claude Code, Codex, Cursor and others get the context they need to make reliable changes.
• Less to maintain. Building, packaging and checking your tools happen in one place, instead of a different setup per format.

Get started

npx maruaudio --help

Node.js 22.12 or later. To set up your coding agent, install the agent skill and Maru's MCP servers:

npx maruaudio skill install
npx maruaudio mcp install --both

See Use Maru from your agent.

Work with musical data

Symbolic provides headless functions for MIDI pitches, chords, rhythm and musical structure. These entries are included starting with version 0.0.3; version 0.0.2 does not provide them.

import { parseNote, parseNoteSet, transposeNoteSet } from "maruaudio/symbolic"
import { parseRhythmSpec } from "maruaudio/symbolic/rhythm"

parseNote("C4").midi // 60
transposeNoteSet(parseNoteSet("60-64-67"), 7).notes.map(note => note.midi)
// [67, 71, 74]
parseRhythmSpec("10010010", "binary").pattern.steps // 8

Use focused entries such as maruaudio/symbolic/grid, maruaudio/symbolic/refs and maruaudio/symbolic/lead-sheet, or import the complete API from maruaudio/symbolic/library. No separate library install is required. See Symbolic and the library guide.

Icons

Use Maru Icons for interface and audio symbols. The independently published package works with Maru controls or any React UI:

npm install maru-icons

import { PlayIcon, KnobIcon } from "maru-icons/react"

<PlayIcon size={20} strokeWidth={1.5} />
<KnobIcon size={24} />

Icons inherit currentColor. Pass size, color, strokeWidth and absoluteStrokeWidth; the latter keeps the stroke thickness stable when the icon size changes. Components default to 24px; the gallery previews use 48px. Use title or aria-label for meaningful standalone icons; name icon-only buttons on the button. Decorative icons are hidden from assistive technology by default. Individual imports such as maru-icons/react/play and raw SVGs such as maru-icons/svg/play.svg are available too.

Browse before drawing another glyph. Suggest or contribute an icon. Retain the package's license notices when redistributing; original Maru work, third-party glyphs and Maru trademarks have distinct terms documented there.

Play a module in React

Import the headless host and hooks from maruaudio/module-player/react. Provide your module declaration and its built web Release, then choose your own controls and optionally render the module's imported face:

import {
  ModulePlayerProvider, ModulePlayerFace, useModulePlayer,
} from "maruaudio/module-player/react"
import { AUDIO_MODULE } from "./my-module"
import MyModuleFace from "./my-module/ui"

const module = {
  definition: AUDIO_MODULE,
  releaseUrl: "/modules/my-module/release.json",
}

function Player() {
  const { controller, error } = useModulePlayer()
  return <>
    <button onClick={() => controller.start().catch(console.error)}>Start</button>
    <button onClick={() => void controller.stop()}>Stop</button>
    {error && <p role="alert">{error}</p>}
    <ModulePlayerFace component={MyModuleFace} />
  </>
}

export function App() {
  return <ModulePlayerProvider module={module}><Player /></ModulePlayerProvider>
}

Copy the complete web export to your app's public module directory. An effect also needs an audio input; an instrument needs notes. The provider adds no controls or global styles. React and React DOM come from your application. Hooks expose schema-bound parameters, factory presets, session state, meters and face props. The controller exposes audio connections, MIDI, resources, state and lifecycle handles. Owned audio resources are cleaned up on unmount.

See Host a module in React for input wiring, supported Release activation, state, embedding and the API.

Learn more

• Documentation
• maru.audio
• GitHub
• Contact

Maru is in alpha and changes quickly.

Copyright

© 2026 Maru Audio. All rights reserved. Terms, including the warranty disclaimer: LICENSE. Third-party notices: NOTICE.