Umbraco Backoffice

If you're building Umbraco backoffice extensions, this shows you how extension types work together in practice. Instead of documenting individual components in isolation, it gives you complete working examples: a basic section with dashboard, a tree browser with workspace, and a full-stack notes app with C# backend. The enforced workflow (plan with wireframes, build, validate with the reviewer agent) might feel rigid, but it prevents the common mistake of picking the wrong extension type and having to rebuild. The examples folder is genuinely useful because you can copy and rename rather than starting from scratch. Think of it as blueprints rather than API docs.

skills.sh installs: 447
GitHub stars: 27
last updated: Aug 21, 2026

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Install

$ npx -y skills add umbraco/umbraco-cms-backoffice-skills --skill umbraco-backoffice --agent claude-code

Installs into .claude/skills of the current project.

Files

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

SKILL.md on GitHub