AppleDevelopmentFoundation

A Codex skill foundation for Apple development. It gives coding agents reusable skills for building iOS 17+ and macOS 14+ apps with SwiftUI, plus guidance for XcodeBuildMCP.

Status: I maintain this solo and use it in my own app work. It is ready to install and use.

Why I made this

I gathered these patterns over the past few months while building local-first iOS and macOS apps. I kept solving the same problems (navigation shells, error states, verification loops), so I wrote them down as skills my agent could reuse. I published the repo so anyone running Codex can use the same foundation, including people opening an agent harness for the first time.

Start in five minutes

git clone https://github.com/brbndon/AppleDevelopmentFoundation.git
cd AppleDevelopmentFoundation
./Scripts/install-skills.sh

That symlinks 17 skills into ${CODEX_HOME:-$HOME/.codex}/skills. Then open Codex and invoke $apple-development-foundation. Ask it to bootstrap a new app, add error states, or improve tab navigation, and it shortlists the right skills from there. docs/quickstart.mdx walks through the full path including XcodeBuildMCP setup.

What it covers

• starting out: apple-development-foundation (routes every request), codex-bootstrap (new app from scratch)
• app UI: swiftui-tab-navigation, swiftui-component-author, apple-design-system, apple-error-states, apple-app-marketing-site, ios-macos-platform-adaptation
• code structure: apple-platform-planner, swift-package-module-author, reusable-code-extractor
• reviews before shipping: swift-concurrency-review, apple-accessibility-review, apple-security-privacy-review, swift-testing-verification, maestro-apple-app-testing
• repo upkeep: codex-skill-maintainer

How it is laid out

• .agents/skills/ holds the skills. manifest.json there is the source of truth for what gets installed.
• Scripts/ holds the installer plus the checks I run after skill changes (verify-skills.sh, test-install-skills.sh).
• docs/ holds the playbook site I use day to day: https://brbndon.github.io/AppleDevelopmentFoundation/
• Templates/ holds drop-in starters (a loading mark, a marketing-site recipe).
• archive/ holds an old Swift package. I keep it frozen and do not expand it.

Requirements

• Codex, the only verified host. Other agent harnesses may work by hand, but I do not verify them.
• Xcode with XcodeBuildMCP for builds and tests (see MCP.md). Maestro only matters for UI flows. Node 22.12+ only matters for the docs site.
• For App Store screenshot sets, I use the external $app-store-screenshots skill (see docs/reference/external-skills.mdx). It is not installed by this repo.

Limits

I review changes alone, so turnaround follows my own app schedule. Skills target the app you are building, not this repo. The archived package stays as is unless I say otherwise. Issues and pull requests are welcome (see CONTRIBUTING.md), but this is a foundation I publish, not a document anyone needs permission to use.

MIT License, Copyright (c) 2026 brbndon. See LICENSE.