# PostFader: FL Studio MCP Server
**Let Claude, Codex, Cursor, or any MCP client work inside the FL Studio project you have open.**
[](https://github.com/synopsys0/postfader-fl-studio-mcp/releases/latest)
[](https://pypi.org/project/postfader-fl-studio-mcp/)
[](https://pypi.org/project/postfader-fl-studio-mcp/)
[](docs/setup.md)
[](https://github.com/synopsys0/postfader-fl-studio-mcp/actions/workflows/ci.yml)
[](LICENSE)
[Quick start](#quick-start) · [What it does](#what-you-can-ask-for) · [Why PostFader](#why-postfader) · [Docs](#documentation) · [FAQ](#faq)
Free and open source. Unofficial: not made by or affiliated with Image-Line.
---
PostFader is an **FL Studio MCP server**. It connects your AI assistant to the
project you already have open, so the AI can read your mixer, channels,
plug-ins and patterns, check your exported mix, write MIDI, and make changes
for you. Every supported change is read back from FL Studio, so you see what
actually happened.
It runs on your computer. There is no PostFader account, cloud service, or
telemetry.
## What you can ask for
| | Ask your AI | What PostFader does |
| --- | --- | --- |
| 🔎 **Understand a project** | *"Which instruments aren't routed to the mixer?"* | Reads routing, effects, channels, patterns, Playlist tracks, and plug-in parameters. |
| 🩺 **Fix a mix** | *"What are the three biggest problems in this bounce?"* | Measures loudness, peaks, tonal balance, stereo width, and vocal masking in the files you export, and compares them with a reference. |
| 🎛️ **Change the session** | *"Pan the backing vocals wider and pull the reverb send down 3 dB."* | Sets faders, pan, sends, routing, names, colors, tempo, transport, and any parameter a loaded plug-in exposes, then reads each one back. |
| 🎹 **Write music** | *"Add an 8-bar D Dorian bassline under my chords."* | Generates chords, melodies, basslines, and drums; writes them to the Piano Roll or exports MIDI files. |
| 🎚️ **Pick sounds** | *"Choose the sounds yourself from what's loaded."* | Picks presets on the instruments in your project and confirms each selection. |
| 🧱 **Run a whole task** | *"Turn this loop into a 16-bar draft, but keep my vocal."* | Runs the job as a checked plan you can resume. Export a bounce and it can review the draft and plan one revision. |
Browse all 85 tools in the [tool reference](docs/tools.md).
## Quick start
**You need:** FL Studio 2026 (26.1.3 or newer) on Windows or macOS,
[Python](https://www.python.org/downloads/) 3.10 to 3.14, and a virtual MIDI
port: the built-in **IAC Driver** on macOS, or a free app such as **loopMIDI**
on Windows.
1. **Run the installer.** Download the Windows or macOS ZIP from the
[latest release](https://github.com/synopsys0/postfader-fl-studio-mcp/releases/latest), extract it, and run the installer inside. It
installs PostFader, copies the bridge script into FL Studio, and asks which
MIDI port to use.
2. **In FL Studio**, open *Options → MIDI settings*. Enable your virtual port as
both input and output, set the input's controller type to
**Universal Bridge**, and give both the same port number.
3. **Connect your AI client** with the configuration the installer prints (see
[Works with](#works-with)).
4. **Ask a question first**, like *"Summarize my project."* PostFader starts
read-only, so nothing changes until you ask for an edit.
Using Python directly? Run `pip install postfader-fl-studio-mcp`, then
`postfader setup`. The [setup guide](docs/setup.md) covers every option, and
`postfader-doctor` pinpoints anything that isn't connected.
## How it works
FL Studio only runs scripts from inside itself, so PostFader talks to a small
controller script, the **Universal Bridge**, over a virtual MIDI port. Audio
analysis works on files you export, because FL Studio doesn't expose its live
output to scripts.
## Why PostFader
- **Nothing changes until you ask.** PostFader starts read-only. Edits need
write mode, which the AI turns on for your session only when you ask for a
change. Reloading the project turns it off again.
- **Changes are checked, not assumed.** After each supported edit, PostFader
reads the value back from FL Studio and reports what actually happened.
- **Your project is never saved for you.** You decide when to save, and FL
Studio's undo history keeps working.
- **It checks your mix, not just your settings.** Mix Doctor, loudness and
true-peak checks, reference comparison, and vocal masking run on the bounces
you choose.
- **It doesn't crowd your AI's context.** Detailed plan formats load only when
the AI needs them, leaving room for your conversation.
- **Windows and macOS, tested on both.** Every change runs the full test suite
on both systems before release.
[See how PostFader compares with other FL Studio MCP servers →](docs/comparison.md)
## Works with
PostFader is a local MCP server, so your AI client must run on the same
computer as FL Studio. `postfader setup` prints ready-to-paste configuration.
| Client | How to connect |
| --- | --- |
| **Claude Desktop** | Paste the generated `claude-json` config, or install the `.mcpb` extension from the release page. |
| **Claude Code** | `claude mcp add-json fl-studio '