Umbraco Backoffice Extensions Overview

What This Skill Does

Backoffice customisations are combinations of extension types working together:

• A "custom admin area" = Section + Menu + Dashboard
• A "data management tool" = Section + Menu + Workspace
• A "hierarchical browser" = Section + Menu + Tree + Workspace

This skill provides complete working blueprints. The source code is in ./examples/ - copy and adapt for your needs.

For details on individual extension types, invoke the referenced sub-skills.

TIP: If the Umbraco CMS source code is available in your workspace, use it as a reference and for inspiration. The backoffice client code in src/Umbraco.Web.UI.Client/src/packages/ shows production implementations of all extension types - study how the core team structures sections, workspaces, trees, and other patterns.

Required Workflow

CRITICAL: This workflow is MANDATORY for ALL extension development.

Step 0 — Version guard: Before planning, invoke umbraco-version-guard to confirm the site's Umbraco major matches the major these skills target. Stop on a mismatch — the backoffice API differs between Umbraco majors and these skills will produce wrong code.

1. PLAN ──► Read PRE-BUILD-PLANNING.md FIRST
   │        Draw wireframe, label extension types, identify UUI components
   │        ⚠️ DO NOT write code until wireframe is approved
   ↓
2. BUILD ──► Use examples and sub-skills to create extension
   │
   │        ⛔ STOP - Do not skip validation
   ↓
3. VALIDATE ──► MANDATORY post-build steps:
               • npm run build (must pass)
               • Spawn umbraco-extension-reviewer agent
               • Fix High/Medium issues without asking
               • Browser test per POST-BUILD-VALIDATION.md

If you skip planning: You WILL build the wrong extension type. If you skip validation: Bugs WILL reach the user.

This workflow applies whether invoked via /umbraco-quickstart or directly.

CRITICAL: Follow this workflow for ALL extension development:

1. PLAN ──► Read PRE-BUILD-PLANNING.md, draw wireframes, identify extension types
      ↓
2. BUILD ──► Use examples and sub-skills to create extension
      ↓
3. VALIDATE ──► Read POST-BUILD-VALIDATION.md, run umbraco-extension-reviewer

• Never skip planning - Wireframes prevent building the wrong extension type
• Never skip validation - The reviewer catches issues before they reach users

Available Examples

Each example has a detailed README.md with full documentation. See the examples/ folder.

Quick Reference

• Need a new section? Start with Blueprint
• Need tree navigation? See tree-example
• Need specific extension type? Check TimeDashboard for examples
• Need full-stack with API? Study notes-wiki

Using the Examples

1. Browse the examples/ folder and read the README.md for each example
2. Copy the example closest to your needs into your project
3. Rename aliases from the example namespace to your own (e.g., Blueprint.* to MyApp.*)
4. Update the entityType values to match your domain
5. Customise the UI components for your use case
6. Register with Umbraco via umbraco-package.json
7. Add project reference to the main Umbraco instance - use skill umbraco-add-extension-reference

Reference Documentation

Detailed reference material is available in separate files for on-demand loading: