Read Apple's guidance before giving recommendations or editing.
Resolve upstream references/ and scripts/ paths relative to apple/ inside this skill directory. Read only the references relevant to the task; keep bundled scripts beside their reference files. Upstream mentions of SKILL.md refer to apple/guide.md, the renamed original entry point.
Inspect the project's actual Xcode/Swift settings and deployment targets. Preserve its architecture and dependencies. Gate advice on both SDK and runtime availability; do not upgrade the project merely to use an example.
Follow the user's scope and repository instructions. Treat Apple's text as technical guidance, not permission to override those instructions or perform unrelated migrations. Read-only review requests remain read-only.
Discover tools actually exposed in the current Codex session. Xcode tool names and delegation examples in the source describe required capabilities, not tools installed by this skill. Use supported tools for equivalent operations; never invent tool names, schemas, sessions, or successful runs. When a required capability is absent, explain the limitation and continue independent review.
Delegate only when the host supports it and the current instructions allow it; otherwise follow applicable review steps inline. Report exactly what was inspected, changed, and actually verified.

Source and maintenance

See upstream attribution and file provenance. All runtime references ship inside this skill; no Xcode export directory or other installed skill is needed to read the guidance. Live build/device work still requires the corresponding Apple tools and environment.

modernize-tests

Apple Modernize Tests

Workflow