Apple updates vended agent skills: Xcode 27 Beta 3 | Pete Goldsmith

Back to blog

Jul 7, 2026

Apple updates vended agent skills: Xcode 27 Beta 3

Xcode 27 beta 3 (27A5218g) landed, so I re-ran the agent skill export for the snapshot repo. Beta 2 was small tweaks. This one changes over 2,600 lines (full commit).

There’s a new skill, adopt-c-bounds-safety. It’s the existing c-bounds-safety skill under a new name, with the adoption-strategies reference expanded. The old one still ships alongside it, unchanged. Looks like a rename caught mid-flight.

audit-xcode-security-settings gets a lot of love in particular. It’s been rebuilt around an approval gate. The audit now opens by briefing you on what it is and how long it will take (about 15 to 30 minutes, by its own estimate), then writes an editable plan file at the project root and changes nothing until you pick Run. Every per-target action gets its own tracked task. The references pick up new guidance for library and framework targets too, telling library authors to keep pointer authentication on and ship universal arm64 + arm64e binaries rather than dodge the larger artifact.

Some of the updates are for formatting and grammar. Parts of the beta 2 text had line wraps in places that made it look copied straight out of a Claude terminal session, and beta 3 cleans them up. Other tweaks seem more substantive. modernize-tests drops its “do not apply when” trigger list in favour of prose about what actually can’t migrate, and gains a closing instruction to split the work over multiple agents when the task is complex.

The new security-skill prose is heavy on em dashes and bold-led bullets, with stage directions like “Keep it tight” thrown in. Bit of Mythos love, potentially?

Watching the evolution of these skills to me is a fascinating window into how Apple are holding agents.