A step beyond autocomplete
Craig Federighi devoted part of the WWDC 2026 keynote to the evolution of the development environment. The agentic coding assistant in Xcode 27 — already announced as part of the Core AI framework — brings a specific capability that goes beyond generating individual snippets: according to Engadget's live blog, "Xcode has a coding assistant that can simulate entire apps." In other words, the system can autonomously build a project, compile it, and simulate its behavior to verify functionality before the developer launches it on a simulator or real device.
Interactive resize and preview
Federighi also demonstrated that developers can resize and interact with app previews directly within the agentic workflow, without leaving the editing context. Apple deferred to subsequent sessions for the underlying API details.
Competitive context
Federighi stated that Xcode is "the best place for agentic coding" — a statement clearly aimed at tools like Cursor, Windsurf, and GitHub Copilot Workspace, which have gained ground among professionals. The ability to simulate entire apps on-device, integrated with Apple's toolchain, is the concrete response: the argument is that no external environment has the same level of access to build, signing, and distribution tools on Apple's platform.