Swift API Design Guidelines

Design APIs that read clearly at the call site and communicate semantic roles rather than implementation details.

Contents

• Scope and Compatibility
• Call-Site Test
• Side Effects and Pairs
• Names and Protocols
• Documentation
• Common Mistakes
• Review Checklist
• References

Scope and Compatibility

This skill owns Swift declaration names, argument labels, mutating/nonmutating pairs, protocol naming, casing, overload clarity, and documentation comments. Route language/type-system mechanics to swift-language, concurrency semantics to swift-concurrency, lint configuration to swiftlint, and project/file naming to the relevant architecture or UI skill.