Plugin Basics
New here? Start with Building Your First Plugin instead — this page is the reference for what you just built.
Folder layout
A plugin is a folder under /plugins/ containing at minimum a plugin.json manifest and an entry file:
plugins/my-plugin/
├── plugin.json ← REQUIRED — manifest
├── my-plugin-init.php ← REQUIRED — entry point, loaded when active
├── admin/
│ └── admin-page.php ← exposes the admin page renderer (optional)
├── assets/{css,js}/
├── lang/ ← front-end translations
│ └── admin/ ← admin translations
├── data/ ← the plugin's own data store (create at runtime)
└── private/ ← secrets, rate-limit stores (create at runtime, .htaccess-protected)
Only plugin.json and the entry file it points to are required — everything else is opt-in, built by the plugin itself using the patterns in the rest of this category.
plugin.json manifest
{
"synaptik_plugin": true,
"name": "My Plugin",
"slug": "my-plugin",
"version": "1.0.0",
"description": "One-line description shown on the Extensions page.",
"author": "Your Name",
"entry": "my-plugin-init.php"
}
| Field | Required | Description |
|---|---|---|
synaptik_plugin | Yes | Must be true — distinguishes a valid plugin folder from anything else under /plugins/ |
slug | Yes | Stable identifier — folder name convention, activation registry key, admin route parameter. Treat as permanent once published |
entry | Yes | Path to the PHP file to require_once, relative to the plugin's folder |
name, description, author, version | No | Display metadata on the Extensions page |
The activation registry
Installing a plugin (uploading a ZIP from Admin → Extensions) does not activate it. Activation state lives in /plugins/plugins.json:
{ "my-plugin": { "active": true } }
A plugin only runs — its entry file is only require_once'd — once activated, via pl_load_active_plugins() (called once from core/functions.php on every request). Deactivating stops it from loading but preserves its data; deleting is only allowed while inactive, so an accidental click can't silently destroy stored data.
Checking if a plugin is active
if (pl_is_active('another-plugin-slug')) {
// ...
}
Rarely needed for your own plugin (if your code is running, you're active by definition) — useful for one plugin checking whether another is present before integrating with it.