An AI design critic that has actually read the HIG

What it does

It’s an agent skill — mostly a large, well-organized pile of reference material plus a routing scheme — that turns Claude Code, Cursor, Codex, and friends into a design reviewer grounded in Apple’s Human Interface Guidelines. Ask it to audit a screen, and it loads the relevant guideline pages first, then reports findings with a What, a Why citing the specific guideline file and heading, and a Fix written in your framework (Flutter, React Native, Tauri, Electron, SwiftUI, UIKit, AppKit).

The interesting bit

The boring part is the value: a pull-hig.mjs script crawls developer.apple.com, renders pages from the same JSON Apple’s site uses, and regenerates the whole reference set — deterministic enough that running it twice and getting a clean git status is the freshness test. There’s also a cross-platform dictionary translating Apple’s vocabulary into Flutter/Electron terms, and a code-audit mode that reads source instead of screenshots, flagging things like hand-drawn Apple Pay buttons (a known Guideline 4.9 rejection cause) with path:line citations.

Key highlights

• 123 generated HIG pages plus a curated Liquid Glass guide, with source links and change dates
• Specialized modes: accessibility, dark mode, iPhone Duo layouts, onboarding, forms, widgets, app icons
• iPhone Duo mode checks both displays, partial fold, and Split View, and flags custom bars that miss system adaptations
• Improvement mode plans a token system and sequences fixes from accessibility to polish
• Refresh script is dependency-free Node 18+, ~170 requests, cacheable

Caveats

• It’s glue plus scraped content, not a tool that runs anywhere — the “skill” is prompt scaffolding and reference files your agent reads
• Apple revises the HIG several times a year, so the bundled pages go stale until someone re-runs the crawler
• tvOS, visionOS, and watchOS sections are deliberately omitted

Verdict

Worth a look if you ship cross-platform apps that should feel at home on Apple platforms and want design feedback with citations rather than an LLM’s generic taste. Skip it if you’re web-only or allergic to Apple’s design opinions.