Project5pi MIDI for Claude

Give Claude a song idea. Get back a real FL Studio project, a mastered MP3 and a MIDI file.

Claude (or any AI, or you) writes a short JSON description of a song: key, tempo, chords, drum grids, melody, arrangement. p5midi writes it straight into an FL Studio .flp, using your own FL Studio template for the sound, renders it with FL Studio's command line, masters it, and measures the result, so an AI that cannot hear still gets told "the intro is louder than the drop" or "the mix is 13 dB bass-heavy" and can fix it.

Not a terminal person? A one-click desktop app (type an idea, click Make; free for 5 songs a month) is in the works: join the waitlist.

No clicking, no MIDI loopback driver, no controller script. The .flp opens in FL Studio with every note, pattern and playlist clip editable.

Listen: three songs written from the example specs, rendered by FL Studio 2026 with only its stock template instruments: trap · lo-fi · house

idea --> Claude --> song.json --> p5midi build --> song.flp (+ song.mid)
                                         |
                    FL64.exe /R  <-------+  (your FL Studio renders it)
                         |
                     song.wav --> master --> song.mp3 --> analyze --> notes back to Claude

Why this exists

FL Studio has a Python API, but it only runs inside the app and only for MIDI controller and piano-roll scripts: it can't create channels, place playlist clips or render. Existing AI bridges drive the open app over a virtual MIDI port, so someone has to have FL open and export by hand. This project goes around the app instead: it reads and writes the project file directly (we worked out the format changes up to FL 2026; see docs/FLP-FORMAT.md) and uses FL's own headless render. One command goes from text to MP3 in about 20 seconds.

Related MCP server: leadsheet

Quick start

Needs Python 3.10+. Rendering needs Windows, FL Studio (20.7 or newer; tested up to FL Studio 2026) and ffmpeg on PATH.

pip install "project5pi-midi-for-claude[mcp] @ git+https://github.com/ProjectFlowmar/project5pi-midi-for-claude"

p5midi templates                          # FL Studio templates on this machine
p5midi inspect HipHop-Trap                # their channels (instruments)
p5midi make examples/night-drive-trap.json -o out/night-drive.flp

make writes night-drive.flp, .mid, .wav and a mastered .mp3, then prints a report like this (trimmed):

"master":   {"lufs": -10.3, "true_peak_db": -1.4},
"sections": [["intro", -14.8], ["hook 1", -8.8], ["break", -12.2], ["hook 2", -8.8], ["outro", -15.5]],
"notes":    []

FL Studio must be closed while rendering; an open FL grabs the command instead.

Use it from Claude

Claude Code / Claude Desktop (MCP). Register the server:

claude mcp add p5midi -- p5midi-mcp

or in Claude Desktop's claude_desktop_config.json:

{ "mcpServers": { "p5midi": { "command": "p5midi-mcp" } } }

Tools: list_templates, inspect_template, spec_format, build_song, make_song, render, analyze_audio, master_audio. Then ask: "Make me a dark 140 BPM trap beat in A minor with a sliding 808, about a minute long."

Claude Code skill. Copy skills/fl-studio-composer into ~/.claude/skills/ to teach Claude the compose → make → read the report → fix loop with the CLI.

The song spec

{
  "template": "HipHop-Trap", "bpm": 140, "key": "A minor",
  "progression": ["i", "VI", "III", "VII"],
  "parts": {
    "drums": {"type": "drums", "channel": "Drums",
              "lanes": {"kick": "x......x..x.....", "clap": "........x.......", "hat": "x.x.x.x.x.x.x.x."}},
    "808":   {"type": "bass",   "channel": "Sub 1", "octave": 1, "rhythm": "x-----.x--.x----"},
    "pad":   {"type": "chords", "channel": "Pad", "progression": ["i7", "VImaj7", "III", "VII"]},
    "hook":  {"type": "melody", "channel": "Synth 1", "notes": [[0, "E5", 0.75], [0.75, "D5", 0.25], [1, "C5", 1]]}
  },
  "arrangement": [
    {"name": "intro", "bars": 4, "parts": ["pad"]},
    {"name": "hook",  "bars": 8, "parts": ["drums", "808", "pad", "hook"]}
  ]
}

Part types: drums (step grids with accents, ghosts, holds and hat rolls), chords (roman numerals with 7/9/sus/borrowed chords, automatic voice leading, optional rhythm), bass (follows chord roots on a rhythm grid, octave jumps), arp (up/down/updown/random, rate, span, gate), melody/notes (note names, MIDI numbers or scale degrees). Plus humanize, swing, velocity, transpose. Full reference: SPEC.md.

Commands

What it checks for you

The analysis is how a model with no ears gets feedback: integrated loudness and true peak, tonal balance in six bands (sub to air), stereo width and whether the low end is mono, loudness per arrangement section, and band-by-band difference from a reference track you like. It turns these into notes such as:

• Section 'intro' (chords, keys) is 3.3 LU louder than the fuller 'break'. Likely too loud: one of chords, keys.

• Very bass-heavy: lows are 13 dB above the mids (1-4 kHz). Melody and chords may be buried.

• Clipping risk: true peak 0.5 dBFS.

(The first one caught a real problem in our first example; the fix was one velocity value.)

Limits, honestly

• The sound is whatever the template's instruments and mixer give you. The tool writes notes and arrangement; it does not load plugins, change presets, or automate mixer knobs (yet). Pick or make a template you like the sound of.

• Rendering is Windows-only (FL's command-line render). Building .flp and .mid files works anywhere.

• Numbers are not taste. The AI can avoid obvious mix mistakes; whether the song is good still needs a human ear.

• The .flp format is undocumented. It's tested on FL Studio 20.5 to 2026 project files (51 files round-trip byte-for-byte; renders verified on 20.7, 24.0, 24.1, 24.2, 25.2 and 26.1 formats). A future FL update may change it; please open an issue with the version.

Development

pip install -e ".[dev,mcp]" mido
pytest            # no FL Studio needed: tests build synthetic projects

Credits and legal

• Thanks to PyFLP for documenting much of the older FLP event map, which made the newer findings possible.

• Other approaches worth knowing: MCP servers that drive a running FL Studio over virtual MIDI, such as flstudio-mcp.

• This project ships no Image-Line files. It uses your own licensed FL Studio installation and templates. FL Studio is a trademark of Image-Line Software; Claude is a trademark of Anthropic. This project is not affiliated with or endorsed by either.

MIT licensed. Made by Project5pi.