Umbraco Extension Registry

What is it?

The Extension Registry is the core system managing all Umbraco backoffice UI elements - almost any UI in the Backoffice is an extension managed by the Extension Registry. The registry allows developers to dynamically add, remove, or modify extensions at runtime using umbExtensionsRegistry. Developers have the same possibilities as Umbraco HQ, meaning you can change almost everything that is by default present in Umbraco.

Documentation

Always fetch the latest docs before implementing:

• Main docs: https://docs.umbraco.com/umbraco-cms/customizing/extending-overview/extension-registry
• Register Extensions: https://docs.umbraco.com/umbraco-cms/customizing/extending-overview/extension-registry/register-extensions
• Replace/Exclude: https://docs.umbraco.com/umbraco-cms/customizing/extending-overview/extension-registry/replace-exclude-or-unregister
• Extension Manifest: https://docs.umbraco.com/umbraco-cms/customizing/extending-overview/extension-registry/extension-manifest
• Foundation: https://docs.umbraco.com/umbraco-cms/customizing/foundation

Workflow

1. Fetch docs - Use WebFetch on the URLs above
2. Ask questions - Register, exclude, or replace? Runtime or static? Conditions needed?
3. Generate code - Implement registry operations based on latest docs
4. Explain - Show what was created and how extensions are managed

Minimal Examples

Register Extension (Runtime)

import { umbExtensionsRegistry } from '@umbraco-cms/backoffice/extension-registry';

const manifest = {
  type: 'dashboard',
  alias: 'My.Dashboard',
  name: 'My Dashboard',
  element: () => import('./dashboard.element.js'),
  meta: {
    label: 'My Dashboard',
    pathname: 'my-dashboard'
  }
};

umbExtensionsRegistry.register(manifest);

Exclude Extension

import { umbExtensionsRegistry } from '@umbraco-cms/backoffice/extension-registry';

// Permanently hide an extension
umbExtensionsRegistry.exclude('Umb.WorkspaceAction.Document.SaveAndPreview');

Unregister Extension

import { umbExtensionsRegistry } from '@umbraco-cms/backoffice/extension-registry';

// Remove extension from registry (can be re-registered)
umbExtensionsRegistry.unregister('My.WorkspaceAction.AutoFillWithUnicorns');

Replace Extension (Overwrites)

const manifest = {
  type: 'workspaceAction',
  alias: 'My.WorkspaceAction.ExternalPreview',
  name: 'My Custom Preview',
  overwrites: 'Umb.WorkspaceAction.Document.SaveAndPreview',
  element: () => import('./custom-preview.element.js'),
  // ... rest of manifest
};

umbExtensionsRegistry.register(manifest);

Replace Multiple Extensions

const manifest = {
  type: 'workspaceAction',
  alias: 'My.CustomSave',
  name: 'My Custom Save',
  overwrites: [
    'Umb.WorkspaceAction.Document.SaveAndPreview',
    'Umb.WorkspaceAction.Document.Save'
  ],
  // ... rest of manifest
};

umbExtensionsRegistry.register(manifest);

Entry Point Registration

// entrypoint.ts
import { umbExtensionsRegistry } from '@umbraco-cms/backoffice/extension-registry';

export const onInit = (host: UmbEntryPointOnInitArgs) => {
  // Exclude default dashboard
  umbExtensionsRegistry.exclude('Umb.Dashboard.UmbracoNews');

  // Register custom dashboard
  umbExtensionsRegistry.register({
    type: 'dashboard',
    alias: 'My.CustomDashboard',
    name: 'Custom Dashboard',
    element: () => import('./custom-dashboard.element.js'),
    meta: {
      label: 'Welcome',
      pathname: 'welcome'
    },
    conditions: [
      {
        alias: 'Umb.Condition.SectionAlias',
        match: 'Umb.Section.Content'
      }
    ]
  });
};

Dynamic Registration from Server Data

import { umbExtensionsRegistry } from '@umbraco-cms/backoffice/extension-registry';

async function registerDynamicDashboards() {
  // Fetch configuration from server
  const response = await fetch('/api/dashboard-config');
  const dashboards = await response.json();

  // Register each dashboard dynamically
  dashboards.forEach(config => {
    umbExtensionsRegistry.register({
      type: 'dashboard',
      alias: config.alias,
      name: config.name,
      element: () => import(config.elementPath),
      meta: {
        label: config.label,
        pathname: config.pathname
      }
    });
  });
}

Conditional Registration

import { umbExtensionsRegistry } from '@umbraco-cms/backoffice/extension-registry';

// Register extension only if condition is met
if (userIsAdmin) {
  umbExtensionsRegistry.register({
    type: 'dashboard',
    alias: 'My.AdminDashboard',
    name: 'Admin Dashboard',
    element: () => import('./admin-dashboard.element.js'),
    meta: {
      label: 'Admin',
      pathname: 'admin'
    }
  });
}

Batch Operations

import { umbExtensionsRegistry } from '@umbraco-cms/backoffice/extension-registry';

// Exclude multiple extensions
const extensionsToHide = [
  'Umb.Dashboard.UmbracoNews',
  'Umb.Dashboard.RedirectManagement',
];

extensionsToHide.forEach(alias => {
  umbExtensionsRegistry.exclude(alias);
});

// Register multiple extensions
const myExtensions = [
  { type: 'dashboard', alias: 'My.Dashboard1', /* ... */ },
  { type: 'dashboard', alias: 'My.Dashboard2', /* ... */ },
];

myExtensions.forEach(manifest => {
  umbExtensionsRegistry.register(manifest);
});

View Registered Extensions

Navigate to: Settings > Extensions Insights in the backoffice to see all registered extensions.

Key Concepts

umbExtensionsRegistry: Central registry for managing extensions

register(): Add new extension at runtime

exclude(): Permanently hide extension (never displayed)

unregister(): Remove extension from registry (can be re-registered)

overwrites: Replace existing extension(s) with custom implementation

Runtime vs Static:

• Static: Use umbraco-package.json for most extensions
• Runtime: Use umbExtensionsRegistry for dynamic/conditional registration

Entry Point: Common place to execute registry operations during startup

Extension Insights: View all registered extensions at Settings > Extensions Insights

Use Cases:

• Hide default Umbraco features
• Register extensions based on server data
• Replace built-in actions with custom logic
• Conditionally enable features
• Dynamic dashboard registration

Sources

• Extension Registry | Umbraco CMS
• Register an Extension | Umbraco CMS
• Replace, Exclude or Unregister | Umbraco CMS

That's it! Always fetch fresh docs, keep examples minimal, generate complete working code.