Apple UI Insider's first issue is out. Every picture in it is drawn twice, once by my own renderer, once by Apple's frameworks, then compared. That check caught a real bug: two renders disagreeing by 3.9%, traced to one coordinate flip, fixed to 0.07%. aleahim.com/blog/apple-u...

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

aleahim.com

Boundless thanks to the remarkable spirits who so generously placed their invaluable hard-won wisdom in our hands: @vanvoorden.bsky.social, @emredeg.bsky.social, @dijamantina.bsky.social, @jordanmorgan10.bsky.social, Howard Oakley and Wayne Bishop

Fatbobman (东坡肘子)@fatbobman.com · last mo.

Fatbobman’s Swift Weekly #143 is now available! When Linux Becomes "Air": Containers, Agents, and a "Desktop War" That No Longer Matters 🔭 Debugging Notes on Two SwiftUI Animation Bugs 🔧 SwiftUI 3D is Flat 🔍 Safari MCP 🔥 SwipeCell weekly.fatbobman.com/p/fatbobman...

SwiftUI looks like it does 3D. So I built the simplest 3D scene, a cube: six faces, one camera. Pure SwiftUI cannot build it. The back face paints over the front at every rotation. The fix exists, visionOS only. aleahim.com/blog/swiftui...

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 r...

aleahim.com

How fragile we are My GitHub account was locked, my public work disappeared behind 404s, and the support path was another broken machine. I wrote about why I moved to Codeberg. aleahim.com/blog/humans-...

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

aleahim.com

Cupertino moved to Codeberg. If you installed through Homebrew, update your tap. The old GitHub tap can leave you on `1.4.1`; the current working release is `1.4.2` from Codeberg. aleahim.com/blog/cuperti...

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.

aleahim.com

Account: bsky.app/profile/dija... A tolerance you're allowed to relax is a wish, not a measurement. I built a from-scratch SwiftUI engine, then 125 differential tests holding it against real SwiftUI: layout to 1e-6, springs to six decimals, pixels byte for byte. aleahim.com/blog/the-swi...

Everyone treats SwiftUI as Apple's big idea. Measured against its own behavior and against Apple's patent, it is one demand-driven graph, the boring tip. The hard engine underneath is Core Animation, by John Harper, who almost no one can name. aleahim.com/blog/swiftui...

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 ...

aleahim.com

Apple's new sample code reads like a brief: four of the 11 new samples are "Integrating Your Music / Messaging / Calendar / Photo App with Apple Intelligence." 19 new frameworks, almost all AI. I put the whole signal offline. aleahim.com/blog/cuperti...

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

aleahim.com

A PR titled "Fix for issue #13" repointed a core dependency in my project to a fork the submitter controlled. It did not even work. And it was one of 36 automated bounty-bot PRs across 34 repos in a day. Read your lockfiles. aleahim.com/blog/indisti...

"Indistinguishable From an Attack"

How an autonomous bounty bot opened a pull request that repointed a core dependency to a fork it controlled

aleahim.com

Left to its defaults, an AI coding agent is a shortcut machine. It wraps a failing call in try? and moves on. It says "tests pass" without running them. Every one is a small lie that compiles. aleahim.com/blog/rules-m...

"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

aleahim.com

Every validator starts as one giant function that walks a tree and appends to an error array. It works. It also rots. OpenAPIKit taught me the fix: a validation isn't code you run, it's a value you build. aleahim.com/blog/validat...

"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 valu...

aleahim.com

"Swift runs everywhere" is usually a slide. So I made it a rule: every platform claim must be a CI gate on every push. Four pure-Swift codebases pass: macOS, Linux, Windows, the browser. One renders PDFs in your tab. aleahim.com/blog/swift-r...

"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 Sw...

aleahim.com

You need a PDF with a couple of formulas and a table, fast. No LaTeX install, no headless browser. Write Markdown, get a real PDF, rendered right here in your browser by a pure-Swift engine: pdf.aleahim.com

I already had a static site generator I liked. Then I wanted diagrams, charts, a per-article PDF, and real math typeset at build time. Couldn't get it all from one tool, so I built one around typed tiles. This post is rendered by it. aleahim.com/blog/why-i-b...

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...

aleahim.com

A search filter that returns the same 88 results for iOS 13 and iOS 18 isn't a filter. It's decoration. That bug became cupertino v1.3.0: one registry, 8 per-source databases, shipped read-only. The unified search.db is gone. aleahim.com/blog/cuperti...

cupertino v1.3.0: The Big Refactor - Aleahim

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.

aleahim.com

Swift is for the Eloi. The framework you live in and the machine humming under the floor were built by the same hands, twelve years apart. We just stopped looking down. aleahim.com/blog/morlock...

The Morlocks Built SwiftUI - Aleahim

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 ...

aleahim.com

It's not RAG., but Cupertino v1.2.0: 92% rank-1 on canonical Apple API lookups, up from 52% in v1.1.0. No vectors, no reranker, just SQLite FTS5 with BM25F and AST extraction at index time. aleahim.com/blog/cuperti...

cupertino v1.2.0: lands the right Apple doc 9 times in 10 - Aleahim

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...

aleahim.com

"The given data was not valid YAML." It was fine. One stray key eleven levels deep, rejected by OpenAPIKit and wrapped by Yams in a useless DecodingError. OpenAPIDoctor, a typed validator + auto-repair CLI for OpenAPI: aleahim.com/blog/why-i-b...

Why I built OpenAPIDoctor - Aleahim

OpenAPIKit's strict parser meets real-world specs. A typed diagnosis CLI with auto-repair, proven across 594 YAML files.

aleahim.com

v1.1.0 of cupertino first shipped with a binary that asked the CDN for the OLD v1.0.2 bundle every single time. No error. Doctor reported green. The download URL is built from one constant the release commit had explicitly not bumped. aleahim.com/blog/cuperti...

v1.0.1: "zero duplicates verified across 405,782 rows." v1.0.2: removed 128,142 of them. They were duplicates the whole time. The v1.0.1 verification query was structurally incapable of finding the bug. Write-up: aleahim.com/blog/cuperti...

Cupertino v1.0 "First Light" is out. Ask an LLM what Swift's Task does and you can still get a Mach kernel essay. Cupertino serves Apple's docs to the model over MCP, ranked correctly. aleahim.com/blog/cuperti... #Swift #MCP #LLM

swifttribune.walidsassi.com/podcast/cupe...

Cupertino v0.10 is out Every Apple framework is now searchable by your AI agent. All 307 of them. 302,424 docs. First community PRs landed too — Agent Skill support from @tijs and a Claude Code plugin from @gpambrozio. The open source dream. aleahim.com/blog/cupertino-10-release/

Built a thing: text your Mac from your phone, it runs an AI coding agent and replies with the result. No terminal, no SSH — just iMessage as a transport layer. Open source, written in Swift. aleahim.com/blog/irelay/

I built iRelay — text your Mac from your phone, it runs Claude Code and texts you back the result. Also, Cupertino updates coming soon. aleahim.com/blog/irelay/

Cupertino v0.9 is out! 🍎 Added docs to work with 8 AI tools aleahim.com/blog/cupertino-09-release/

Cupertino v0.8.0 - SwiftSyntax AST indexing for smarter Apple docs search. Symbol declarations now rank higher than text mentions. 4 new semantic search tools. 698 tests. aleahim.com/blog/cupertino-08-release

Finally crawled ALL of Apple's docs. 302K pages. Cupertino v0.7.0 now lets you filter by OS version — ask Claude for iOS 17+ APIs only. No more deprecated suggestions. Also: HIG search, teasers that teach AI where to look, and 40K kernel docs. aleahim.com/blog/cupertino-07-release/

234K Apple docs in your terminal. 287 frameworks. Cupertino v0.5.0 just dropped. Five days of crawling Apple's documentation so you don't have to. Found 25K Kernel docs alone. IOKit, Mach, BSD - the stuff that's impossible to Google. aleahim.com/blog/cupertino-05-release

Cupertino v0.4.0 - Apple docs MCP server for AI agents New: HIG support, framework aliases, Swift-org fixes Key insight: AI agents read search results every time, but tool descriptions once. Put hints in the output, not the docs. aleahim.com/blog/cupertino-04-release