plugin-host

Pexip plugin host

Pexip plugins are sandboxed iframes that drive the host app via postMessage RPC. The plugin can:

• Add toolbar buttons / participant menu items / settings menu items
• Open panel widgets (visible iframes inside the meeting UI)
• Show modal forms / prompts / toasts
• Call most of the conference SDK (mute, kick, setLayout, breakout, sendMessage, etc.)
• Subscribe to events (participant joins, conference status, language change, transfer events)

Webapp3's PluginManager is the host implementation. ~1,000 LOC across src/plugins/ plus the @pexip/plugin-api SDK. This skill captures the architecture; if you need to write plugins (the iframe side), see Pexip's separate plugin developer portal.

The architecture in one diagram

manifest.json declares plugins[]
        ↓
<PluginManager> renders one hidden <iframe sandbox> per plugin
        ↓
plugin loads, calls registerPlugin() which sends "syn" RPC via postMessage
        ↓
host validates: is the message source one of our iframes?
        ↓
host creates Channel, sends "ack" reply, syncs initial state to plugin
        ↓
plugin issues UI/conference RPCs (button:add, widget:add, conference:mute, etc.)
        ↓
host updates React state for UI ops, calls infinity SDK for conference ops
        ↓
host subscribes to all infinity signals → forwards to plugins as events

Manifest entry

{
    "plugins": [
        {
            "src": "./plugins/my-plugin/index.html",
            "id": "my-plugin",
            "sandboxValues": ["allow-scripts", "allow-same-origin"]
        }
    ]
}

Webapp3 renders this as:

<iframe
    id={plugin.id}
    sandbox={getValidSandboxValues(plugin)}
    src={plugin.src}
    aria-hidden
    className="b-zero"  // 0×0, invisible
/>

Plugins are logical, not visible — they're invisible iframes that issue commands. To show UI, plugins request a widget (a separate visible iframe) or call ui:button:add / ui:form:open / etc. (rendered natively by the host).