How do I install the Validate Vst3 Editorhost skill?

Run npx skillmds@latest add iplug3/validate-vst3-editorhost in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Validate Vst3 Editorhost safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Validate Vst3 Editorhost?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Validate Vst3 Editorhost free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Validate Vst3 Editorhost?

iPlug3 (@iplug3) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Validate Vst3 Editorhost by iplug3 — Agent Skill

Name: Validate Vst3 Editorhost
Author: iPlug3

Validate Vst3 Editorhost

Test VST3 plugin UIs (.vst3 bundles) using Steinberg's EditorHost without a full DAW. Use when user says "test the plugin UI", "open in editorhost", "show the .vst3 editor", or wants to visually inspect the VST3 editor. For functional validation use validate-vst3 instead.

iPlug3 8bf8179 3.0 KB Updated Sep 17, 2026

File contents

VST3 EditorHost

Minimal VST3 host for testing plugin UIs without a full DAW.

Plugin Install Locations

editorhost accepts a direct path to a .vst3 bundle.

Platform	User Location	System Location
macOS	`~/Library/Audio/Plug-Ins/VST3/`	`/Library/Audio/Plug-Ins/VST3/`
Windows	`%LOCALAPPDATA%\Programs\Common\VST3\`	`C:\Program Files\Common Files\VST3\`
Linux	`~/.vst3/`	`/usr/lib/vst3/` or `/usr/local/lib/vst3/`

Instructions

Build EditorHost from the VST3 SDK if not already built (see Building EditorHost below)
Run: editorhost /path/to/plugin.vst3
The plugin UI window should appear — verify layout, controls, and resizing
Test multiple editor instances with --secondWindow
If the UI doesn't appear, verify the plugin passes validator tests first

Usage

# Basic usage - load plugin and show UI
editorhost /path/to/plugin.vst3

# With component handler (tests host callbacks)
editorhost --componentHandler /path/to/plugin.vst3

# Open second window (tests multiple editor instances)
editorhost --secondWindow /path/to/plugin.vst3

# Specify a particular effect class by UID
editorhost --uid "ABCD1234..." /path/to/plugin.vst3

Binary Locations

Platform	Typical Path
macOS	`<vst3sdk>/build/bin/Release/editorhost.app/Contents/MacOS/editorhost`
Windows	`<vst3sdk>\build\bin\Release\editorhost.exe`
Linux	`<vst3sdk>/build/bin/Release/editorhost`

Building EditorHost

Clone the VST3 SDK if you don't have it, then build:

cd <vst3sdk>
cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build --target editorhost

Linux: Requires X11 and GTK3 development libraries:

# Debian/Ubuntu
sudo apt install libx11-dev libgtkmm-3.0-dev libxcb-util-dev libxcb-cursor-dev libxcb-keysyms1-dev libxcb-xkb-dev

# Fedora
sudo dnf install libX11-devel gtkmm3.0-devel xcb-util-devel xcb-util-cursor-devel xcb-util-keysyms-devel libxkbcommon-x11-devel

Troubleshooting

Plugin doesn't load

Check the plugin path is correct
Verify the plugin passes validator tests first
Check logs: Console.app (macOS), Event Viewer (Windows), or stderr (Linux)

UI doesn't appear

The plugin might not have an editor (hasEditor() returns false)
Check if createEditor() is returning a valid view
Linux: Ensure X11 display is available (echo $DISPLAY)

UI appears but is blank/wrong size

Check defaultEditorSize() returns valid dimensions
For WebView UIs, check the HTML content is being set correctly
Try with --secondWindow to see if the issue is with first-time setup

---name: validate-vst3-editorhostdescription: Test VST3 plugin UIs (.vst3 bundles) using Steinberg's EditorHost without a full DAW. Use when user says "test the plugin UI", "open in editorhost", "show the .vst3 editor", or wants to visually inspect the VST3 editor. For functional validation use validate-vst3 instead.---# VST3 EditorHostMinimal VST3 host for testing plugin UIs without a full DAW.## Plugin Install Locations`editorhost` accepts a direct path to a `.vst3` bundle.| Platform | User Location | System Location ||----------|--------------|-----------------|| macOS | `~/Library/Audio/Plug-Ins/VST3/` | `/Library/Audio/Plug-Ins/VST3/` || Windows | `%LOCALAPPDATA%\Programs\Common\VST3\` | `C:\Program Files\Common Files\VST3\` || Linux | `~/.vst3/` | `/usr/lib/vst3/` or `/usr/local/lib/vst3/` |## Instructions1. Build EditorHost from the VST3 SDK if not already built (see Building EditorHost below)2. Run: `editorhost /path/to/plugin.vst3`3. The plugin UI window should appear — verify layout, controls, and resizing4. Test multiple editor instances with `--secondWindow`5. If the UI doesn't appear, verify the plugin passes `validator` tests first## Usage```bash# Basic usage - load plugin and show UIeditorhost /path/to/plugin.vst3# With component handler (tests host callbacks)editorhost --componentHandler /path/to/plugin.vst3# Open second window (tests multiple editor instances)editorhost --secondWindow /path/to/plugin.vst3# Specify a particular effect class by UIDeditorhost --uid "ABCD1234..." /path/to/plugin.vst3```### Binary Locations| Platform | Typical Path ||----------|-------------|| macOS | `<vst3sdk>/build/bin/Release/editorhost.app/Contents/MacOS/editorhost` || Windows | `<vst3sdk>\build\bin\Release\editorhost.exe` || Linux | `<vst3sdk>/build/bin/Release/editorhost` |## Building EditorHostClone the [VST3 SDK](https://github.com/steinbergmedia/vst3sdk) if you don't have it, then build:```bashcd <vst3sdk>cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Releasecmake --build build --target editorhost```**Linux**: Requires X11 and GTK3 development libraries:```bash# Debian/Ubuntusudo apt install libx11-dev libgtkmm-3.0-dev libxcb-util-dev libxcb-cursor-dev libxcb-keysyms1-dev libxcb-xkb-dev# Fedorasudo dnf install libX11-devel gtkmm3.0-devel xcb-util-devel xcb-util-cursor-devel xcb-util-keysyms-devel libxkbcommon-x11-devel```## Troubleshooting### Plugin doesn't load- Check the plugin path is correct- Verify the plugin passes `validator` tests first- Check logs: Console.app (macOS), Event Viewer (Windows), or stderr (Linux)### UI doesn't appear- The plugin might not have an editor (`hasEditor()` returns false)- Check if `createEditor()` is returning a valid view- **Linux**: Ensure X11 display is available (`echo $DISPLAY`)### UI appears but is blank/wrong size- Check `defaultEditorSize()` returns valid dimensions- For WebView UIs, check the HTML content is being set correctly- Try with `--secondWindow` to see if the issue is with first-time setup

Frequently asked questions