AgentLoops

FL Studio, but for AI agents. A song is a multi-agent pipeline you can see, hear and edit like a beat. Channels are agents, notes are agent calls, patterns loop, mixer buses carry each agent's output to the next one, and what reaches Master is the result. A song is also music: every channel has an instrument, so a song plays as you build it and exports to WAV or MP3.

Use it from Claude Code, Codex, Cursor, opencode or any MCP client. The coding agent drives the studio through the Studio MCP server, and you watch each edit land in the studio window. You don't need an API key. script channels run locally, and harness channels hand their notes to your coding agent. Only llm.agent channels call the Claude API.

Requirements

• Node.js 24 or newer.

• A Chromium-family browser (Chromium, Chrome, Brave, Edge or Vivaldi) for the app window and for exporting audio with no studio open. The app window opens in your default browser when it is Chromium-family, else the first one on PATH; without one, the studio opens in your default browser.

• ffmpeg, optional, for MP3 export. WAV needs nothing extra.

Related MCP server: strudel-ai

Install

npm install -g @nawka12/agentloops

That gives you the agentloops command. To try it without installing, use npx @nawka12/agentloops <command>.

Straight from GitHub:

npm install -g --allow-git=root github:nawka12/agentloops

npm 12 refuses git installs unless you allow them, and --allow-git=root allows only this one. If npm then warns that the package's prepare script was blocked, you can ignore it: the package was already built while it was installed.

From a clone:

npm install   # also builds dist/
npm link

You can also skip the install and run node src/cli.ts <command> from the clone.

Make a song with Claude Code

agentloops init my-song --harness claude-code   # a starter song, .mcp.json and the AgentLoops skill
cd my-song
agentloops studio song.alp.json                 # opens the studio in its own window

In a second terminal, in the same folder:

claude                                          # approve the "agentloops" MCP server when asked

Then ask for what you want:

Make a kawaii future-bass song at 160 BPM: a supersaw chord stab, a wobbly sub bass, chip arps and a lyric line. 16 bars with an intro, a build and a drop. Play it for me, then export it as an MP3.

The agent reads the manual from its skill, writes the song, plays it and exports the MP3. Every change shows up in the studio, labeled with who made it, and Ctrl+Z undoes any of them. You can keep editing in the studio at the same time: the agent sees your changes on its next read.

Other harnesses use the same setup with a different --harness:

The studio's ⇄ connect button writes the same files for the song that is open.

Try the demo

agentloops studio "$(npm root -g)/@nawka12/agentloops/examples/kawaii-bass.alp.json"

Press Space to play. Shift+click ⤓ saves an MP3 next to the song. It is 52 bars, with 8 script channels for chords, bass, arp, bell hook, drums, riser, vocal chops and a lyricist. The lyricist listens to the vocal chops and sends each sung line to Master, so the Monitor (F11) shows the lyrics as they're sung.

Commands

How it works

• The studio is the host. agentloops studio holds the song, the undo history and the runs. agentloops mcp relays every tool call to the open studio over localhost, using a token the studio writes to .agentloops/studio.json. With no studio open, it hosts the song itself.

• Three scopes. read can only look. edit can change the song, and every change is saved and undoable. run can also play the song, which spends money if it has llm.agent channels, so runs are capped by the song's budgets and the --budget the harness was started with.

• Time is barriers. Notes at the same position run in parallel, and a note starts only after every note ending at or before it has finished. Playback tempo is a speed limit, so a slow agent shows up as a held note.

• Takes are cached. Every run is saved as a take in .agentloops/takes.sqlite. A voice whose prompt and inputs did not change replays from the cache for free, which is what makes looping a pattern cheap.

• Generators. script runs JavaScript in a sandbox. llm.agent calls Claude with tools and MCP servers. harness hands a note to the connected coding agent: the run pauses until the agent answers with voice_reply.

Docs

• docs/manual.md: the manual for agents and people, covering the project format, every MCP tool and how to make music. init copies it into the skill or AGENTS.md.

• SPEC.md: the full design, with the FL Studio research behind it.

• docs/case-study-blender-mcp.md: why the studio is the MCP host.

Credits

The piano, sax, trumpet, trombone, upright, vibes, strings, violin, pizz, harp, glock and timpani sounds, the guitars heavy, crunch, chug and clean, and the drum kits' cymbals are recordings: Salamander Grand Piano by Alexander Holm (CC BY 3.0), the University of Iowa Musical Instrument Samples, VSCO 2 Community Edition (CC0), and the Musyng Kite guitars from midi-js-soundfonts (CC BY-SA 3.0). Details in ui/samples/NOTICE.