Total CMS Extension Starter

A template for building Total CMS extensions. Clone this repo, rename it, and start building.

What's Included

This starter demonstrates every extension point:

Feature	File	Description
Twig function	Extension.php	starter_greet() function
Twig filter	Extension.php	reverse_words filter
Twig global	Extension.php	Example in register() (commented out)
CLI command	src/Command/GreetCommand.php	tcms acme:greet
API route	src/Action/ApiHelloAction.php	Protected API at /ext/acme/starter/api/hello
Public route	src/Action/PublicStatusAction.php	Unauthenticated at /ext/acme/starter/status
Admin page	src/Action/DashboardAction.php	Admin page at /admin/ext/acme/starter/dashboard
Admin nav	Extension.php	Sidebar link with custom SVG icon
Dashboard widget	templates/widgets/starter.twig	Widget on admin home
Event listener	Extension.php	Logs object create/update events
Automation	Extension.php	prune-drafts scheduled job (+ commented event-driven example)
Custom field type	src/Field/ColorPickerField.php	Native HTML color picker field
MCP tool	Extension.php	acme_search_inventory — query the inventory from an AI agent
MCP tool with progress	Extension.php	Bulk-reindex example with SSE progress notifications (commented)
MCP resource	Extension.php	acme://message/of-the-day — addressable content for AI agents
MCP resource template	Extension.php	URI template acme://inventory/{sku} for unbounded resource sets (commented)
Admin CSS asset	assets/colorpicker.css	Styles for the color picker field
Admin JS asset	Extension.php	Example in register() (commented out)
Frontend CSS/JS assets	Extension.php	Examples in register() (commented out)
Container definition	Extension.php	Example in register() (commented out)
Page middleware	Extension.php	Example in register() (commented out)
Read-only schema	schemas/starter-items.json	Example collection schema (Pro+)
Installable schema	Extension.php	Example in boot() (commented out, Pro+)
Settings	settings-schema.json	Configurable greeting message
Icon	icon.svg	Displayed on the extension card in the admin UI
Manifest links	extension.json	"Documentation" and "Dashboard" links on the admin card
Review note	extension.json	Plain-language note shown on the pre-enable review screen

Getting Started

1. Clone this repo into your T3 extensions directory:

cd tcms-data/extensions/
mkdir your-vendor
cd your-vendor
git clone https://github.com/totalcms/extension-starter.git your-extension
cd your-extension

2. Update extension.json with your extension's ID, name, and details:

{
"id": "your-vendor/your-extension",
"name": "Your Extension"
}

3. Update the PHP namespace in composer.json and all PHP files:

"autoload": {
"psr-4": {
"YourVendor\\YourExtension\\": "src/"
}
}

4. Install dependencies and generate the autoloader:

composer install

5. Enable the extension:

tcms extension:enable your-vendor/your-extension

6. Delete the parts you don't need and start building.

Directory Structure

your-extension/
extension.json # Manifest (required)
Extension.php # Entry point (required)
icon.svg # Extension icon (optional)
composer.json # Dependencies and autoloading
settings-schema.json # Settings form definition
src/
Action/ # HTTP action handlers
Command/ # CLI commands
schemas/ # Read-only schemas (Pro+)
templates/ # Twig templates

Manifest Links

Add a links array to extension.json to surface buttons on the admin Extensions card:

"links": [
{"label": "Documentation", "url": "https://docs.totalcms.co/extensions/"},
{"label": "Dashboard", "url": "/admin/ext/acme/starter/dashboard"}
]

Each entry needs a label and a url.

• URLs starting with http:// or https:// are treated as external and open in a new tab.
• Relative URLs (admin pages your extension registers) only show when the extension is enabled — they wouldn't resolve otherwise. External links are always shown so users can read your docs before enabling.

Review Note

When a user enables an extension that touches sensitive capabilities — public (unauthenticated) routes, listening to all content changes, registering services, or exposing tools/resources to AI agents over MCP — Total CMS shows a short pre-enable review screen before the extension turns on. (Extensions that use none of those just enable in one click.) The screen also lists any high-risk patterns a static source scan finds in your code (shell_exec, raw network calls, etc.).

The reviewNote field in extension.json is your message at the top of that screen — your chance to explain, in plain language, what your extension does and why it needs the access it asks for:

"reviewNote": "Receives Stripe webhooks at a public endpoint to confirm payments, and watches new orders to send notifications. No data leaves your site except the Stripe calls you configure."

Guidelines:

• Write for the site owner, not a developer. Say what the extension does and why it needs each sensitive capability.
• Be specific about public endpoints and data access — those are what users worry about.
• Keep it short — a sentence or two. It's a reassurance, not a manual.
• You'll see this exact screen when you enable your own extension during testing, so you can preview how it reads.

Two behaviors worth knowing as you build:

• Capabilities you add in a later version default to off for users who already had your extension enabled. Total CMS surfaces the new capability in the extension's settings as a toggle, so the user opts in deliberately — adding a capability in an update won't silently start using it.
• An update that introduces high-risk code patterns (caught by the source scan) disables the extension until the user reviews and re-enables it. Clean updates install without interruption. So keep risky calls intentional and explainable.

reviewNote is optional — but on an extension that uses any sensitive capability, a good note is the difference between a confident "Enable" and a nervous one.

Schemas

Two ways to ship schemas with an extension. Both require the Pro edition.

Approach	Where it lives	Editable by user?	Use when
Read-only	schemas/yourname.json in the extension	No — owned by the extension	The schema is core to the extension's behavior and shouldn't be modified
Installable	$context->installSchema([...]) in boot()	Yes — copied once into tcms-data/.schemas/	The schema is a starting point the user is expected to customize

Read-only schemas are auto-discovered. They show up in the admin schemas view alongside built-in schemas, and can be referenced by collections. Disabling the extension's Schemas capability hides them.

installSchema() is a one-shot copy: it skips silently if a schema with the same id already exists, so subsequent boots don't overwrite the user's edits.

Version Requirements

The requires block in extension.json is enforced before the extension can be enabled:

"requires": {
"totalcms": ">=3.3.0",
"php": ">=8.2"
}

If the running Total CMS or PHP version doesn't satisfy these constraints, the extension is still listed on the Extensions admin page but the Enable button is disabled and a yellow warning panel explains why. This means users can see your extension exists and read its docs, but they can't enable it on an unsupported runtime.

Documentation

• Extensions Overview
• Manifest Reference
• Extension Points
• Events
• Schemas

License

MIT