Agent skill · software engineering · charleswiltgen
axiom-concurrency
Use when writing ANY async code, actors, threads, or seeing ANY concurrency error. Covers Swift 6 concurrency, @MainActor, Sendable, data races, async/await patterns.
Why this skill is useful
Provides specific patterns and practices for Swift 6 concurrency that the AI wouldn't reliably generate on its own.
What it needs
About 5k tokens when loaded. Last updated 2026-08-06. 1,103 stars on the source repository.
What this skill does
Concurrency You MUST use this skill for ANY concurrency, async/await, threading, or Swift 6 concurrency work. <!-- AXIOMAUDITORINLINEBEGIN — rewritten for Codex by scripts/build-codex.ts; do not hand-edit --> Auditors are skills here. Where this router says "Launch some-auditor agent", invoke the matching Codex skill instead — same procedure, no Claude Code agent required. Available: axiom-audit-concurrency. The ones that shell out — builds, tests, simulators, crash symbolication — need shell access to run. <!-- AXIOMAUDITORINLINEEND --> Quick Reference Symptom / Task Reference ---------------- ----------- async/await patterns, @MainActor, actors See skills/swift-concurrency.md Data race errors, Sendable conformance See skills/swift-concurrency.md Swift 6 migration, @concurrent attribute See skills/swift-concurrency.md Actor definition, reentrancy, global actors See skills/swift-concurrency-ref.md Task/TaskGroup/cancellation API See skills/swift-concurrency-ref.md AsyncStream, continuations See skills/swift-concurrency-ref.md DispatchQueue → actor migration See skills/swift-concurrency-ref.md Mutex (iOS 18+), OSAllocatedUnfairLock See skills/synchronization.md Atomic types, lock vs actor decision See skills/synchronization.md MainActor.assumeIsolated See skills/assume-isolated.md @preconcurrency protocol conformances See skills/assume-isolated.md Legacy delegate callbacks See skills/assume-isolated.md Warning-free build crashes with dispatchassertqueuefail See skills/isolation-inheritance-diag.md Crash signature swifttaskcheckIsolatedSwift See skills/isolation-inheritance-diag.md Core Data context.perform runtime crash inside @MainActor class See skills/isolation-inheritance-diag.md Combine .map/.sink crash from receive(on:) placement See skills/isolation-inheritance-diag.md Delegate method crash from isolation inheritance (CLLocationManager, NSDocument, AVAudioPlayerDelegate, WKNavigationDelegate, PHPhotoLibraryChangeObserver) See skills/isolation-inheritance-diag. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills charleswiltgen/axiom-concurrency--0d3e9b