PostFader

io.github.synopsys0Published by GitHub account synopsys0v12.0.3Updated Oct 24, 2026

FL Studio MCP server: read, mix, compose, and edit your open FL Studio project from any MCP client.

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Overview

AI-generated overview

Local MCP server that connects an AI assistant to the open FL Studio project so it can read the mix, edit channels and write MIDI.

What you can do
Read routing, effects, channels, patterns, Playlist tracks and plug-in parameters in the open project, and summarize it read-only at first. Set faders, pan, sends, routing, names, colors, tempo, transport and plug-in parameters, reading each change back. Analyze exported bounces for loudness, peaks, tonal balance, stereo width and vocal masking, and compare against a reference. Generate chords, melodies, basslines and drums into the Piano Roll or as MIDI files, and pick presets on loaded instruments. Run multi-step jobs as a resumable checked plan, including reviewing a draft bounce and planning one revision.
When to use it
Useful when you work in FL Studio and want an assistant to inspect, mix, edit or compose inside the project you already have open, or to review exported bounces, rather than only describing clicks.
Requirements
Runs locally on the same computer as FL Studio, on Windows or macOS. Needs FL Studio 2026 version 26.1.3 or newer, Python 3.10 to 3.14, and a virtual MIDI port (IAC Driver on macOS, loopMIDI or similar on Windows). Set FL_BRIDGE_ENABLE_MIDI to 1, FL_BRIDGE_MIDI_PORT to the exact virtual port name, and FL_STUDIO_USER_DATA_DIR to the FL Studio user-data directory. The bridge script must be installed in FL Studio and the port enabled as input and output with controller type Universal Bridge. No MCP
Before you install
Edits change your open project: write mode must be turned on, and reloading the project turns it off again. It never saves for you, so use FL Studio's undo and try first edits on a copy. On macOS, loading plug-ins needs Accessibility access. Audio analysis only covers files you export, not live output. It is unofficial and not affiliated with Image-Line.

Installation

In SourceWeft

  1. Open PostFader in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

[PostFader, the FL Studio MCP server]

PostFader: FL Studio MCP Server

Let Claude, Codex, Cursor, or any MCP client work inside the FL Studio project you have open.

[Latest release] [PyPI] [Python] [Platforms] [CI] [License]

[Download for Windows] [Download for macOS]

Quick start · What it does · Why PostFader · Docs · 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 AIWhat 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.

Quick start

You need: FL Studio 2026 (26.1.3 or newer) on Windows or macOS, Python 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, 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).
  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 covers every option, and postfader-doctor pinpoints anything that isn't connected.

How it works

[Your AI client talks to PostFader on your computer; PostFader reaches the Universal Bridge script inside FL Studio over a virtual MIDI port; the bridge reads and changes your open project. Exported audio is analyzed by PostFader directly.]

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 →

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.

ClientHow to connect
Claude DesktopPaste the generated claude-json config, or install the .mcpb extension from the release page.
Claude Codeclaude mcp add-json fl-studio '<the fl-studio entry from claude-json>'
Codex (CLI, IDE, app)Run the Codex installer ZIP, or postfader setup --client codex-toml --register-codex.
CursorPaste the claude-json entry into ~/.cursor/mcp.json.
Other MCP clientsAny client that can launch a local stdio server. Use the same command, arguments, and environment.

Documentation

GuideWhat's in it
Setup and troubleshootingInstallers, MIDI settings, every client, upgrades, and the doctor
Tool referenceAll 85 tools and 8 resources, grouped by task
FAQShort answers to common questions and problems
ComparisonPostFader next to other FL Studio MCP servers and Gopher
Production RunsMulti-step jobs, resuming, and stopping
Creation ReviewReviewing a draft bounce, revising it, and preparing delivery
Sound SelectionHow PostFader picks presets from loaded instruments
Plug-in supportParameter control, presets, and compatibility reports
FL Studio limitsWhat FL Studio's scripting API can't do
Security and privacyWhat runs where, and how to report a vulnerability
All documentationArchitecture, contracts, release notes, and more

FAQ

What is an FL Studio MCP server?

MCP (Model Context Protocol) is the open standard AI assistants use to call tools. An FL Studio MCP server gives the assistant tools for FL Studio, so it can read and change your project instead of only describing what to click.

Which FL Studio versions work?

FL Studio 2026, version 26.1.3 build 5336 or newer. Older builds are refused because they lack MIDI-scripting fixes PostFader relies on.

Do I need loopMIDI?

On Windows you need one virtual MIDI port; loopMIDI is a common free choice. On macOS, enable the built-in IAC Driver in Audio MIDI Setup.

Can it hear my song?

It analyzes audio files you export. FL Studio doesn't give scripts access to its live output, so PostFader can't listen in real time.

Can it load plug-ins?

On macOS, yes: it adds instruments and effects from FL Studio's Add menu (this needs Accessibility access). On Windows, load them yourself; PostFader can then control their parameters.

Will it mess up my project?

It starts read-only, checks every supported change, and never saves. Use FL Studio's undo if you don't like an edit, and try your first edits on a copy.

More in the FAQ.

Contributing and security

Bug reports, plug-in compatibility results, and pull requests are welcome; see CONTRIBUTING.md and GitHub Discussions. Report vulnerabilities privately as described in SECURITY.md.

PostFader is licensed under the Apache License 2.0. FL Studio is a trademark of Image-Line, which does not make or endorse this project.

Source: README.md at commit a3d3b88

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

4
  1. v12.0.3LatestOct 5, 2026
  2. v12.0.0Oct 5, 2026
  3. v11.0.0Oct 2, 2026
  4. v10.0.0Sep 16, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts