Apple opens Siri AI to every app, and lets developers teach it skills

With the first iOS 27.3 betas, Apple opened a Developer Preview letting any developer expose app content and actions to Siri AI through App Intents, dropping the previous limit to predefined categories like messaging and to-do lists. It also introduced "skills" — Markdown SKILL.md files with a name, one-line description and plain-language guidance — that teach Siri AI to combine several actions into one job, though Apple says skills are guidance rather than a deterministic script. During the preview Siri AI works with an app only in developer-run builds or internal TestFlight, with App Store submissions opening in the spring and customer availability "in a few months".