armcord/docs/plugin-system.md

Legcord Plugin System

Legcord now supports filesystem plugins loaded from:

<userData>/plugins/<plugin-id>/

Each plugin can provide separate runtime entries for:

• main (Electron main process)
• preload (Legcord preload context)
• renderer (Discord page context)

Manifest

Create a manifest.json in your plugin folder:

{
    "id": "example-plugin",
    "name": "Example Plugin",
    "version": "1.0.0",
    "description": "Example plugin with all three targets",
    "author": "you",
    "compatibleVersions": ["1.3.x"],
    "main": "main.js",
    "preload": "preload.js",
    "renderer": "renderer.js"
}

Required fields:

• id
• name
• version

Optional fields:

• description
• author
• compatibleVersions
• main
• preload
• renderer

compatibleVersions supports exact versions and x wildcard prefixes:

• "1.3.0" (exact)
• "1.3.x" (any patch in 1.3)
• "*" (all versions)

If the running Legcord version does not match, the plugin is marked incompatible and cannot be enabled/loaded. Plugins are disabled by default until explicitly enabled in the Plugins settings page.

Lifecycle

Main and preload entries can export either:

• activate(api) named export
• default export function

Renderer entries run as plain script files and can expose:

• module.exports.activate = (api) => { ... }
• module.exports.default = (api) => { ... }
• globalThis.activatePlugin = (api) => { ... }

Plugin Control API

From window.legcord.plugins:

• list()
• setEnabled(id, enabled)
• reload(id)

Main-process entries are enabled/disabled live. Preload/renderer entries are loaded on startup/navigation and will reflect enable state on next load.

Patcher API (Spitroast-style)

Plugin APIs include:

• api.patcher.before(name, parent, callback, oneTime?)
• api.patcher.after(name, parent, callback, oneTime?)
• api.patcher.instead(name, parent, callback, oneTime?)

Callbacks use the same semantics as Spitroast (args mutation/replacement, return value replacement, instead chaining).
The return value is an unpatch() function.

Example

export function activate(api) {
    const unpatch = api.patcher.before("fetch", window, (args) => {
        api.logger.log("fetch called with", args[0]);
    });

    api.onCleanup(() => {
        unpatch();
    });
}

Notes

• Plugin enable state is stored in config under pluginStates.
• Plugin folders are scanned from disk at startup.
• Invalid manifests or missing entry files are skipped safely.

Full Example Plugin

A complete example is available at:

• docs/examples/hello-plugin/manifest.json
• docs/examples/hello-plugin/main.js
• docs/examples/hello-plugin/preload.js
• docs/examples/hello-plugin/renderer.js

To test it:

1. Copy docs/examples/hello-plugin into your runtime plugins directory:
   • <userData>/plugins/hello-plugin
2. Restart Legcord or use the Plugins settings page:
   • enable/disable
   • reload
3. Open DevTools and watch for [Plugin:hello-plugin] logs.