BeatFlow: AI Full Arrangement Generator

BeatFlow is an LLM-powered music prototyping tool. Enter a prompt and it generates multi-track MIDI arrangements (chords, bass, drums). It features a full in-browser Piano Roll for editing, playback, and direct MIDI export to your DAW.

BeatFlow is not an MP3 generator. It utilizes the LLM as a Music Director capable of genuine music theory reasoning. Instead of predicting waveforms, the LLM architects a complete musical structure—planning sections, energy curves, and harmonic progressions—before composing. The output is a fully editable, structurally coherent MIDI arrangement.

• Includes a fully functional web-based Piano Roll editor.
• Export standard MIDI files to drop directly into Ableton Live, FL Studio, or Logic Pro.
• Uses LLMs to understand music theory, generating structured sections (Intro, Groove, Breakdown) rather than random notes.

Quick Deployment

The project is split into a Frontend (Next.js) and Backend (FastAPI).

• Python 3.10+
• Node.js 18+ (pnpm recommended)

Backend Setup (Python/FastAPI)

cd beatflow
pip install -r requirements.txt

Configure Environment:

Create a .env file and add:

OPENROUTER_API_KEY=your_key
LLM_BASE_URL=https://openrouter.ai/api/v1 # (or other OpenAI-compatible endpoint)
LLM_MODEL=your_model_name # (e.g., gpt-4o, gemini-3-pro)

# Optional proxy settings
HTTP_PROXY=
HTTPS_PROXY=

Start server:

python main.py

Frontend Setup (Next.js)

cd frontend
pnpm install
pnpm dev

Open http://localhost:3000 to start creating.