This week's SwiftLee Weekly covers:

• Agent hooks in Claude Code, Cursor, and Codex explained
• AGENTS . md files with personal rules, while working in teams
• Close-sourcing open-source projects

Next week, I'll be releasing the first 3 modules of my new AI Fundamentals course. Make sure to join the waitlist while you can by clicking here.

Enjoy this week's SwiftLee Weekly!

THIS WEEK'S BLOG POST

​Agent hooks in Claude Code, Cursor, and Codex explained​

Your agent forgets a rule in AGENTS.md every now and then, at least, that's my experience. A hook never does and it really impacted my way of working. In this week's article, I'm explaining how hooks work in Claude Code, Cursor, and Codex, and show one that filters noisy Xcode build output.
​avanderlee.com​

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CURATED FROM THE COMMUNITY

​Guidelines and Guardrails Belong in Git​

How do you deal with personal AGENTS . md rules while working in a team? Allen Pike shines a light on this matter.
​allenpike.com​

​SwiftData rollback after a failed save​

Storing data failed, but what do you do at that point? What if a SwiftData save fails? Roland Leth shares his experience of unexpected behavior.
​roland.leth.ro​

​Bring Receipts​

I used to rely on automated PR reviews, but I'm more and more relying on local reviews that happened either way. Agentic development is changing how we used to work, and this article by Alex Grebenyuk discusses one of those cases.
​kean.blog​

​Closing Up: Why I’m making some of my projects closed-source​

What I experience with my article, Daniel Saidi experiences with open-source projects. People care less, copying seems more normal than ever. I've seen my open-source projects being copied too. It's sad, but the new reality.
​danielsaidi.com​

​Interesting ways of using Swift optionals​

John Sundell makes you think different about optionals in Swift. An unexpected learning journey for something that feels so fundamental!
​swiftbysundell.com​

SWIFT EVOLUTION

An overview of last week's Swift Proposal state changes. Check them out when they're in review, as it's your opportunity to influence the direction of Swift's future.

WHAT I'M WORKING ON

Hello, Metal

The iPhone Duo is here for a while, so is the Simulator inside Device Hub. Screenshots aren't required for submission, but soon will. There's a big difference with the Duo Simulator compared to others: it allows you to adjust the fold.

RocketSim supports recordings and screenshots, so I had to add support for capturing that folding state. What started as "Let's use Xcode Instruments to optimize SwiftUI", ended in "Let's rewrite to RealityKit" and followed by "Let's use Metal and move to the GPU".

The thought I had?

"Why not, the agent can do it either way!"

Which is still a very weird thought. I would've never picked Metal a year ago, as I have no experience in it at all. It would not be optimal, it would take me weeks to learn that new technology and I would not even know if it would work well.

Now, one week later, it works super well. Performance is unlike anything I had before. It took me a lot of instrument traces, but I simply couldn't accept a lower quality barier as agents give no excuses. Yet, it's a blessing and a curse: you'll have to watch your deadlines and prevent yourself from endlessly optimizing. I guess the freedom as an indie developer doesn't help here, ha!