Unity UI System Selector

A Unity project guide for choosing between UGUI, the older GameObject-based interface system, and UI Toolkit, the newer web-inspired system.

In plain words
What is it for?
Use it when starting a Unity UI, selecting a framework for menus or HUDs, building editor tools or data-driven interfaces, or planning a UI migration.
Why use it?
It explains the trade-offs between the two systems and connects the choice to Unity version, project type, UI complexity, and team experience.

Skill for Claude CodeCodex

Part of the unity-dev-toolkit plugin — 7 skills, 3 commands, 4 agents shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/dev-gom/claude-code-marketplace/unity-ui-selector
Any agent
npx skills add Dev-GOM/claude-code-marketplace --skill unity-ui-selector
Clone the repo
git clone --depth 1 https://github.com/Dev-GOM/claude-code-marketplace

Made for: Claude Code, Codex.

Or install unity-dev-toolkit, the plugin that ships this one along with the rest of its 7 skills, 3 commands, 4 agents.

Per session 27 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 716 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00027 $0.00716
Opus 5 $0.00014 $0.00358
Sonnet 5 $0.00005 $0.00143
Haiku 4.5 $0.00003 $0.00072

Measured 3d ago against content hash f5a29e04c515, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

Unity UI System Selector scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/unity-dev-toolkit/skills/unity-ui-selector/SKILL.md · 74 lines

How it starts

The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Unity UI System Selector

Helps you choose the appropriate UI system for your Unity project and provides implementation guidance for both UGUI and UI Toolkit.

Two UI Systems

UGUI (Legacy) - GameObject-based (2014). Mature, works on all Unity versions, large community. Weaker: Complex UI performance, limited styling, no live reload.

UI Toolkit (Modern) - Retained mode, web-inspired UXML/USS (2021.2+). Better performance, live reload, data-binding. Weaker: Requires 2021.2+, smaller community, limited 3D world-space UI.

Decision Framework

Use UGUI if:

  • Unity < 2021.2
  • Simple UI (menus, HUD)
  • 3D world-space UI needed
  • Team knows UGUI well / tight deadline
  • Legacy project

Use UI Toolkit if:

  • Unity 2021.2+ and new project (future-proof)
  • Complex/data-driven UI (inventory, skill trees)
  • Editor tools (inspectors, windows) - strongly recommended
  • Web dev background (HTML/CSS)
  • Large-scale UI (MMO, strategy games)

When in doubt: For new projects on Unity 2021.2+, UI Toolkit is recommended.

Comparison

Feature UGUI UI Toolkit
Version 4.6+ 2021.2+
Performance Simple UIs All UIs
Styling Inspector CSS-like USS
Layout Manual/Groups Flexbox-like
Editor Tools Good Excellent
Runtime UI Excellent Good
3D World UI Excellent Limited

Migration

See migration-guide.md for UGUI → UI Toolkit migration strategy (3-4 months for medium projects).

UI System Support Matrix

Unity Version UGUI UI Toolkit (Editor) UI Toolkit (Runtime)
2019.4 LTS ✅ Full ✅ Basic ❌ No
2020.3 LTS ✅ Full ✅ Good ⚠️ Experimental
2021.3 LTS ✅ Full ✅ Excellent ✅ Production
2022.3 LTS+ ✅ Full ✅ Primary ✅ Full

When to Use vs Other Components

Use this Skill when: Choosing between UGUI and UI Toolkit, understanding UI system trade-offs, or planning UI migration

Read the full file on GitHub · 74 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 74 lines · 27 tokens per session scan A f5a29e04c515

Subscribe to this mod's changes

Unity UI System Selector is a skill published in the GitHub repository Dev-GOM/claude-code-marketplace (97 stars, last pushed 7mo ago), licensed Apache-2.0. It adds 27 tokens to every session and 716 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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