dimillian/skills: Thomas Ricouard's 16 Codex Skills for Apple Platforms and Code Review

Thomas Ricouard — the developer behind Ice Cubes, the open-source Mastodon client for iOS — works on Apple platforms daily, and his personal agent setup has become a public reference. dimillian/skills packages the skills he actually uses: 16 focused, self-contained skills for iOS and macOS work, multi-agent review workflows, React performance, and skill curation. The repo is MIT-licensed and sits at 3.9k stars.

Why This Skill Matters

The standout entries are the "swarm" skills. bug-hunt-swarm runs a read-only four-agent bug investigation — one agent on reproduction, one on code-path tracing, one on regressors, one on the fastest proof step — then returns a ranked root-cause path. review-swarm does the same for diffs: four agents look for behavioral regressions, security risks, performance or reliability issues, and contract or test coverage gaps, then hand back a prioritized fix path. Alongside them sit practical Apple-platform workhorses: an iOS debugger that drives a booted simulator through XcodeBuildMCP, macOS SwiftPM packaging and notarization without an Xcode project, and an App Store changelog skill that turns git history into release notes.

Installation

The README documents a manual install: place the skill folders under $CODEX_HOME/skills.

git clone https://github.com/dimillian/skills
mkdir -p "$CODEX_HOME/skills"
cp -r skills/<skill-folder> "$CODEX_HOME/skills/"

Each skill is self-contained — the SKILL.md in each folder carries the triggers, workflow guidance, and examples — so you can copy only the ones you need instead of all sixteen.

Real Workflow: Run a Bug Hunt Swarm

You have a bug report you cannot reproduce and a suspicion it is a regression.

1. Copy the bug-hunt-swarm folder into your skills directory.
2. In Codex, describe the bug and ask for a swarm investigation. The skill orchestrates four read-only agents — reproduction, code-path tracing, regressors, and the fastest proof step.
3. Read the output: a ranked root-cause path pointing at the most likely culprit, with the proof step you can run first.

Because the swarm is read-only, it is safe to point at a repo mid-sprint; it reports instead of editing.

Real Workflow: App Store Release Notes From Git History

Shipping a new version and dreading the "What's New" text? The app-store-changelog skill collects changes since the last tag, filters for user-visible work, and rewrites it into concise release-note bullets — excluding the internal refactors nobody's users care about.

Generate App Store release notes for the upcoming version

Tips

• Start with project-skill-audit: it analyzes a project's past sessions, memory, existing skills, and conventions to recommend which new skills are actually worth adding.
• Use review-and-simplify-changes before opening a PR — it reviews a git diff for reuse, quality, and clarity, then optionally applies safe, behavior-preserving fixes.
• swift-concurrency-expert targets Swift 6.2+ issues: actor isolation, Sendable violations, main-actor annotations, and data-race diagnostics.
• The repo is actively maintained — the README notes skills should have a clear, single purpose, which is why there are sixteen small ones rather than one giant file.

When Not to Use This

This is a personal collection, oriented around Codex — the documented install path is $CODEX_HOME/skills, not a marketplace or npx command. If you want an indexed registry with search and versioning, a curated catalog like the ones on our leaderboard fits better. And if your work is server-side Linux or Windows, the Apple- and React-heavy focus covers little of it.

See the leaderboard for more skills.