Swift

Use this skill for native Apple-platform work involving Swift, SwiftUI, XcodeGen, xcodebuild, code signing, or device deployment. Repository instructions own the concrete project path, schemes, destinations, signing team, and deployment host.

XcodeGen projects

Treat project.yml as the source of truth. Do not hand-edit project.pbxproj in a generated project.

targets:
  ExampleApp:
    type: application
    platform: iOS
    sources:
      - path: ExampleApp/Sources

• Add source files below the configured source glob, then run xcodegen generate.
• Review and commit generated project changes when the repository tracks them.
• Treat changes outside documented generated paths as unexpected drift.
• Keep shared modules independent from application-only types so they remain easy to test.

Verification

Run the repository's own scheme and destination when they are declared:

xcodegen generate
xcodebuild -scheme "$SCHEME" -destination "$DESTINATION" test CODE_SIGNING_ALLOWED=NO

For a self-contained file on a remote macOS builder, copy it to a temporary directory and use the target SDK's compiler for a fast type-check. This is a focused preflight, not a replacement for building the generated project and running its tests.

Validate plist and entitlement files with plutil -lint before a signed build.

Signing and capabilities

• Store the development-team identifier and signing configuration in repository-local build settings or an ignored .xcconfig; do not bake personal account data into reusable guidance.
• Prefer automatic signing only when the repository has explicitly opted into it.
• Add capabilities through the target's entitlements and required usage-description keys, then regenerate the project before building.
• Keep App Store Connect credentials in an approved secret store. Never commit private keys or pass secret material through logs.

Remote signed builds

Code signing can depend on the interactive macOS security session. A background SSH session may therefore fail even when the login keychain is unlocked. If a repository supports remote signed builds, use its documented GUI-session LaunchAgent bridge and marker protocol.

Load references/codesign-bridge.md before designing or debugging that bridge. The repository must supply its own labels, paths, schemes, team settings, and device selection.

Never

• Never hand-edit a generated project.pbxproj.
• Never treat a focused swiftc -typecheck as the full project gate.
• Never assume code-signing identities work in a background SSH security session.
• Never publish signing-team identifiers, device identifiers, account names, host aliases, or private-key paths in a portable skill.