Swift Concurrency

Swift 6's strict concurrency checking is a minefield of actor isolation warnings and Sendable conformance errors, and this skill gives you the triage workflow to fix them systematically. It covers the Swift 6.2 approachable concurrency features like default MainActor isolation, the @concurrent attribute for background work, and nonisolated(nonsending) behavior that keeps async calls on the caller's actor. The guide walks through isolated conformances, structured concurrency patterns with TaskGroup, and when to use sending parameters versus just slapping @unchecked Sendable on everything. If you're migrating a codebase from @preconcurrency shims or trying to understand why your UI code is suddenly yelling about data races, this is the reference you want open in a side window.

skills.sh installs: 4.5K
GitHub stars: 1.3K
last updated: Aug 21, 2026

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$ npx -y skills add dpearson2699/swift-ios-skills --skill swift-concurrency --agent claude-code

Installs into .claude/skills of the current project.

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Swift Concurrency

Review, fix, and write concurrent Swift code targeting Swift 6.3+. Gate Swift 6.4 / Xcode 27 beta cleanup APIs behind explicit toolchain and availability checks. Apply actor isolation, Sendable safety, and modern concurrency patterns with minimal behavior changes.