Introducing Apple UI Insider
A new newsletter that draws every picture twice, once with a clean-room renderer, once with Apple's own frameworks, and publishes what's different
All articles
SwiftUI 3D is Flat
SwiftUI's iOS and macOS 3D is per-view projected 2D output composited by painter's order, with no shared-space depth-sorted hierarchy, and the APIs that would fix it are visionOS-only, proven with a rendered counterexample and four executable witnesses
Humans Don't Work at GitHub
GitHub made my work disappear, put a broken machine gate in front of appeal, and gave me no human path back
Cupertino moved to Codeberg. Update your Homebrew tap.
Cupertino v1.4.2 moves the working Homebrew tap and binary distribution to Codeberg, with setup assets served from Fly.
"The SwiftUI Oracle: Measuring a Clean Room Against the Real Thing"
How I prove a from-scratch SwiftUI engine is correct by holding it against real SwiftUI in 125 differential tests, with the actual code, the harness, the firewall, and the floating-point floor that makes agreement mean identical
SwiftUI Is One Graph, Over 40+ Years of Engineering
SwiftUI is the thin graph sitting above 40+ years of engineering. Measured against the real framework and read against Apple's own patent, it is a single demand-driven graph, and the least remarkable engine in the stack it rests on. Here is SwiftUI laid bare, with a hint of the far more interesting machines underneath.
What Apple Wants You to Build This Summer (You Can Read It in the Docs)
Apple's new frameworks and sample code read like a brief, and Cupertino v1.4.0 puts the whole signal offline
"Indistinguishable From an Attack"
How an autonomous bounty bot opened a pull request that repointed a core dependency to a fork it controlled
"The rules my AI coding agent is not allowed to break"
How a pile of repeated corrections became the rulebook I load into every coding agent, and what writing it down taught me about my own code
"Validations Are Values"
Most validation code is one giant function that walks a tree and appends to an error array through a forest of if statements. OpenAPIKit showed me a better way, a validation is a small composable value, the description states the correct state, and every error already knows where it lives
"Swift Runs Everywhere. I Checked."
Four of my Swift projects run right now on macOS, Linux, Windows, and inside the browser. A static site generator, a Markdown to PDF engine, a YAML parser, and a 2D vector graphics engine, all pure Swift, all with CI proving every platform on every push.
"Markdown to PDF in your browser, in pure Swift"
A pure-Swift Markdown to PDF engine compiled to WebAssembly, with a live in-browser playground
Why I built TileDown
I already had a static site generator I liked, right up until I wanted diagrams, charts, a per-article PDF, real math, and a path to dynamic content. So I built one around a typed tile model, and this post is built by it.
OpenAPIDoctor WebAssembly readiness
A first compiler-grounded check of whether OpenAPIDoctor can become a local-first browser tool.
cupertino v1.3.0: The Big Refactor
v1.3.0 is the architecture release: eight per-source databases derived from one registry, shipped read-only, with the legacy unified search.db retired for good.
The Morlocks Built SwiftUI
The cynical read is that Apple kept the real tools and handed us toys. But the same engineer built Core Animation in 2007 and co-built SwiftUI in 2019, and that one fact says the opposite. On why the foundation never left, and the debt that comes due the day the abstraction breaks.
cupertino v1.2.0: lands the right Apple doc 9 times in 10
Search-quality release. AI coding assistants now land the right Apple documentation page on the first try 9 times out of 10, up from 5 out of 10 in v1.1.0. Cross-validated on three independent corpora, zero regressions. The architecture, and what it still gets wrong, in writing.
Cupertino v1.1.0: my Apple docs index was 30% lies and I didn't know
A 3 a.m. SQL query found one row of HTTP poison in the search index. Pulling on that thread unraveled 13 ways Apple's CDN lies to crawlers, plus a release bug where the binary cheerfully downgraded every user to the previous bundle.
Why I built OpenAPIDoctor
OpenAPIKit's strict parser meets real-world specs. A typed diagnosis CLI with auto-repair, proven across 594 YAML files.
Cupertino v1.0.2: the duplicate that `LOWER(uri)` could not see
A third of the search index was the same Apple page indexed twice. The verification query that "proved" it wasn't could not have seen the bug. What v1.0.2 ships, and three takeaways from the audit.
Cupertino v1.0.0 "First Light"
First release stable across crawl, index, rank, serve, and distribute. Search that finally returns the right answer, one bundle, MCP spec 2025-11-25.
Cupertino v0.10: Full Coverage and Community Contributions
307 frameworks, 302,424 docs, Agent Skills, Claude Code plugin, and the first community PRs.
iRelay: Text Your Mac, Run an AI Agent
A Swift daemon that turns iMessage into a remote terminal for Claude Code
Cupertino v0.9: Multi-Agent Support and MCP Protocol Upgrade
Cupertino now works with OpenAI Codex, Cursor, VS Code Copilot, Zed, Windsurf, and opencode. Plus MCP protocol upgrade to 2025-06-18.
Cupertino v0.8.0: AST Indexing and a Major Architecture Refactor
SwiftSyntax enables semantic code search. A deep refactoring of the codebase delivers cleaner results and better AI capabilities.
Cupertino v0.7.0: 302K Docs, OS Version Filtering, and Teaching AI to Dig Deeper
The complete Apple documentation crawl is done. Now you can filter by iOS 17+ and Claude finally knows where to look for answers.
Cupertino v0.5.0: 234K Docs, 287 Frameworks, and the Roadmap Ahead
The biggest documentation update yet - nearly double the docs, plus what's coming next for the Apple documentation MCP server.
Cupertino v0.4.0: HIG Support, Framework Aliases, and Release Engineering Lessons
New features for Apple documentation search, plus a cautionary tale about release processes and why order matters when tagging.
Cupertino v0.3.4: One-Line Install & 150K+ Apple Docs
Install Cupertino with a single command - signed, notarized, and ready in seconds. Now with 150,000+ Apple documentation pages.
Cupertino v0.3.0: From 20 Hours to 30 Seconds
The new setup command downloads pre-built databases instantly - no more crawling Apple's documentation for hours
Cupertino: 27 Issues Down, Just Getting Started
From MCP server to a complete Apple documentation ecosystem with pre-crawled docs and 606 sample projects
Cupertino: Offline Apple Documentation for AI Agents
An MCP server that gives Claude Desktop offline access to 22,000+ Apple documentation pages
Building a Concurrency-Safe Bearer Token Middleware for Swift OpenAPI Clients
Elegant, Thread-Safe Authentication for OpenAPI Runtime
From ExtremePackaging to OpenAPI Integration
Building a Full OpenAPI Workflow on Top of the Extreme Packaging Architecture
Introducing OpenAPILoggingMiddleware
Elegant, Structured Request Logging for OpenAPI-Driven Swift Servers
ExtremePackaging
Example of Extreme Packaging in Swift
CVBuilder: A Swift Package for Professional CV Management
A Swift package for building and rendering CVs in multiple formats
Bringing Advanced SwiftUI Animations to macOS
A port of SwiftUILab's Advanced Animations that also supports macOS
Core Animation Layers forming a 3D cube
Core Animation in 2.5D