Build, test, and simulator control for Xcode projects from any agent.
Claude Code can't see Xcode's build errors unless you hand them over. XcodeBuild MCP plus a formatter that strips the noise gives the agent a real edit-build-test loop for SwiftUI work — the difference between guessing and iterating.
Eight days migrating a legacy widget suite to WidgetKit with Claude Code and XcodeBuild MCP: timeline budgets, a haunted pbxproj, and $84 of tokens.
Agent converts @StateObject to @State (or reorders wrapped properties) as part of an 'observability migration' and every preview in the file dies with 'Compiling failed: cannot preview in this file' or a XCPreviewAgent crash. Builds fine, runs fine on device — only previews break.