strudel-live

An Ableton Live extension built with @ableton-extensions/sdk that renders Strudel code into audio clips. The code is stored inside each clip's WAV file (in a custom strd RIFF chunk), so it is the clip's source of truth and travels with the Live set.

Get Started

Learn about building extensions: https://ableton.github.io/extensions-sdk/

Setup

• The path to Ableton Live's Extension Host module is stored in .env as EXTENSION_HOST_PATH. The generator filled this in for you; edit it if your install moves.
• Turn on Developer Mode in Live's settings, or npm start will fail with "Failed to connect to Live within 10s".

Usage

• Right-click an empty clip slot on an audio track → New Strudel clip… The editor starts with example code laid out as three scenes (see Scenes), which adds two scenes below the slot and a track per part.
• Right-click a Strudel audio clip → Edit Strudel… to change its code and re-render it. The clip is replaced in place, keeping its color (a playing Session clip stops).

Stems

Each labelled block in the code renders to its own clip, on a track named after the label, so the parts can be mixed and processed separately in Live:

kick: s("bd*4");
bass: note("<c2 ab1>(3,8)").s("sawtooth");

• Each stem's clip is named after its label, on every render. A clip from code without labels keeps the name you give it.
• The stems sit side by side: in the same Session row, or at the same Arrangement position. Editing any of them re-renders all of them in place.
• A new label goes on a free track with that name, or a new track. A label removed from the code has its clip deleted (the track stays).
• Muted blocks (_kick:) render silent clips. Anonymous $: blocks become "Strudel 1", "Strudel 2"… in order, so name blocks that should keep their track.
• Code without labels renders a single clip, as before.

Scenes

In Session View, one piece of code can fill several scenes. Define each part once, then list which parts play in each scene:

let kick = s("bd*4");
let hat = s("hh*8").gain(0.6);
let rollinghat = s("hh*16").gain(0.4);
let bass = note("<c2 ab1>(3,8)").s("sawtooth");

scenes({
  intro: { hat },
  verse: { kick, hat, bass },
  drop: { kick, hat: rollinghat, bass }, // rollinghat goes on the hat track
});

• Each scene is a row, named after it, and each part is a track, named after its key (so { kick } puts kick on a kick track). Clips are named after the variable they were written with, so hat: rollinghat puts a rollinghat clip on the hat track. A part left out of a scene has no clip there, so launching that scene stops its track.
• Rows match scenes by position: renaming a scene in code renames the Live scene, and reordering scenes moves their clips. Scenes added to the code are inserted below the group, moving the rest of the set down. A scene removed from the code has its clips deleted, but the Live scene stays.
• Every scene is rendered as its own loop of the editor's Bars length.
• Pick which scene Preview plays with the Scene menu, shown once the code has been evaluated.
• For now, code uses either labels or scenes(), not both, and scenes only work in Session View.

How it works

• src/extension.ts registers the context menu actions and places rendered clips in Live.
• src/server.ts serves the editor UI on 127.0.0.1 and receives rendered audio from it.
• ui/ is the editor dialog. It runs Strudel and renders patterns offline with an OfflineAudioContext at the song tempo (one cycle = one 4/4 bar), one render per labelled block.
• src/wav.ts writes 32-bit float WAVs with the strd chunk and reads it back.

Scripts

npm start                  # build + run in Live's Extension Host
npm run build              # production build of the extension and UI
npm run build:dev          # dev build (sourcemaps, not minified)
npm run package            # build for production + create a .ablx archive
npm test                   # unit tests (Vitest)
npm run check              # typecheck + lint + format check + unit tests
npm run test:e2e           # build the UI + run the editor's browser tests (Playwright)

The browser tests drive the editor dialog in headless Chromium against the real editor server, standing in for Live's dialog bridge. Install the browser once with npx playwright install chromium. Anything that needs Live itself still has to be checked by hand with npm start.

License

This project is licensed under AGPL-3.0-or-later, the same license as Strudel, which it bundles.

The Ableton Extensions SDK and CLI are proprietary and are not included in this repository. They are installed from vendor/, which you populate with your own copy of the SDK.