swift-concurrency
Resolve Swift concurrency compiler errors, adopt approachable concurrency (SE-0466), and write data-race-safe async code. Use when fixing Sendable conformance errors, actor isolation warnings, or strict concurrency diagnostics; when adopting default MainActor isolation, @concurrent, nonisolated(nonsending), or Task.immediate; when designing actor-based architectures, structured concurrency with TaskGroup, or background work offloading; or when migrating from @preconcurrency to full Swift 6 strict concurrency.
Profile →npx skills add dpearson2699/swift-ios-skills --skill swift-concurrency --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# 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. ## Contents - [Triage Workflow](#triage-workflow) - [Swift 6.2 Language Changes](#swift-62-language-changes) - [Actor Isolation Rules](#actor-isolation-rules) - [Sendable Rules](#sendable-rules) - [Structured Concurrency Patterns](#structured-concurrency-patterns) - [Task Cancellation](#task-cancellation) - [Actor Reentrancy](#actor-reentrancy) - [AsyncSequence and AsyncStream](#asyncsequence-and-asyncstream) - [`@Observable and Concurrency`](#observable-and-concurrency) - [Synchronization Primitives](#synchronization-primitives) - [Common Mistakes](#common-mistakes) - [Review Checklist](#review-checklist) - [References](#references) ## Triage Workflow When diagnosing a concurrency issue, follow this sequence: ### Step 1: Capture context - Copy the exact compiler diagnostic(s) and the offending symbol(s). - Identify the project's concurrency settings: - Swift language version (must be 6.2+). - Xcode/to
- Contents
- Triage Workflow
- Step 1: Capture context
- Step 2: Apply the smallest safe fix
- Step 3: Verify
- Swift 6.2 Language Changes
- SE-0466: Default MainActor Isolation
- SE-0461: nonisolated(nonsending)
- @concurrent Attribute
- SE-0472: Task.immediate
- SE-0475: Transactional Observation (Observations)
- Isolated Conformances
- Clock Epochs
- Actor Isolation Rules
What does the swift-concurrency skill do?
Resolve Swift concurrency compiler errors, adopt approachable concurrency (SE-0466), and write data-race-safe async code. Use when fixing Sendable conformance errors, actor isolation warnings, or strict concurrency diagnostics; when adopting default MainActor isolation, @concurrent, nonisolated(nonsending), or Task.immediate; when designing actor-based architectures, structured concurrency with TaskGroup, or background work offloading; or when migrating from @preconcurrency to full Swift 6 strict concurrency.
How do I install it?
Run `npx skills add dpearson2699/swift-ios-skills --skill swift-concurrency --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From dpearson2699/swift-ios-skills, a repository with 963 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.