Issue 739

16^th January 2026

Written by Dave Verwer

Comment

If you’ve spent any time at all reading about AI coding agents, you’ll likely have heard that people get better results when working with languages other than Swift.

Is that because Swift isn’t as AI-friendly as other languages? Absolutely not. In fact, I’ve seen people say that type-safe languages produce better results as the agent can rely on the compiler to automatically catch basic errors. No, I believe there are two main reasons you don’t get quite as good results with Swift and SwiftUI:

1. Swift has a much smaller footprint of publicly available open-source code compared to other languages like Python and JavaScript. Less training data means less language knowledge.
2. Swift and SwiftUI have both seen sustained and significant changes since their releases, and they continue right up to today with major changes like Swift concurrency constantly moving the goalposts.

There’s so much churn in not only best practices with the language and frameworks, but also with the basics of creating a working app.

So I’ve been interested to receive several recommendations of a tool that really helps the agents get to grips with the current state of Swift. Cupertino is a Model Context Protocol (MCP) server that crawls Apple’s locally installed developer documentation, Swift.org (including Swift Evolution proposals, which often contain really great documentation), the HIG, and more.

It even has access to all package repository information (courtesy of the Swift Package Index package list) so it’s much less likely to hallucinate packages that sound like they’ll solve your exact problem. 😂

I’ve not had a chance to try it in a real-world project yet, but I’ve had enough people reach out and suggest I link to it that I thought I’d make it the focus of this week’s comment. Give it a try if you’re working with an agent or other LLM-based coding assistant.

– Dave Verwer

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News

What a lovely thing Peter Friese has done! He has automated the production of a beautiful PDF file from the DocC version of The Swift Programming Language. You can download a pre-built release or build it yourself if you’re curious how he did it, too!

Tools

Here’s yet another tool to help LLM coding agents work with your project! Mikkel Malmberg’s latest project is a command line tool that can automate and test the UI of Mac apps. It includes instructions for the agent in the form of a skill, too, so agents will be able to figure out what they need to test and use the tool to verify your app’s UI.

What a great article from Paul Samuels on abstracting away Docker from a multi-person app development team. SwiftUI is perfect for building little tools like the ones in this post.

Code

Nikita Vasilev’s SwiftUI and UIKit form validation library isn’t new, but I hadn’t seen it until his Community Showcase forum post earlier this week. I love that it splits the validation itself from reporting validation issues back to the UI, so you don’t need to take both if you want it to fit better with the rest of your app. The README file is comprehensive, and there’s fantastic documentation if you need more.

Every time I hear people talk about setting up non-trivial Universal Links for their app, I hear stories of pain and suffering. I can’t imagine a better guide to getting everything correct than the one in Alberto De Bortoli’s latest blog post.

Business and Marketing

I enjoyed this post from Slaven Radic on marketing his Finalist app. He talks about the other aspects of success that can come from advertising on personal sites run by influential people. The kind of results that App Store or Facebook Ads could never deliver.

Books

There has been a lot written on the internet over the past few years about using AI inside your apps. 😬 Some of what you’ll find is great, and some … not so much. The initial release of Paul Hudson’s latest book contains only the first of many chapters, but it already comprehensively covers the iOS 26 Foundation Models and comes with a load of sample code. Best of all, it’s written with Paul’s typical teaching style, which I know you all love.

Videos

This is a fun one! Shai Mishali has an Apple TV app in beta which uses the WWDC Index’s catalogue of 3,667 WWDC (2000 to 2025) sessions, plus various Tech Talks. The app looks beautiful, and while it’s not fully released, you can join a TestFlight to give it a try right now!

Jobs

Senior iOS Engineer @ alba – We have a unique approach to identifying opportunities, entering markets, and scaling our products. This approach puts us on a fast trajectory for maximizing the reach and delight our products create. Founded about three years ago, our products have been used by more than 50M users. – Remote (within European timezones) or on-site (United Kingdom)

And finally...

You won’t need a pixel font every day of your life, but when you do…

Oh, and if you’ve not played Time Flies yet, please do. It’s very charming.