Use when writing ANY code with async, actors, threads, or seeing ANY concurrency error. Covers Swift 6 concurrency, @MainActor, Sendable, data races, async/await patterns, performance optimization.
/plugin marketplace add CharlesWiltgen/Axiom/plugin install axiom@axiom-marketplaceThis skill inherits all available tools. When active, it can use any tool Claude has access to.
You MUST use this skill for ANY concurrency, async/await, threading, or Swift 6 concurrency work.
Use this router when:
ios-concurrency vs ios-performance: When app freezes or feels slow:
ios-concurrency vs ios-build: When seeing Swift 6 concurrency errors:
Rationale: A 2-second freeze during data loading is almost always await on main thread or missing background dispatch. Domain knowledge solves this faster than Time Profiler.
Swift 6 concurrency patterns → /skill axiom-swift-concurrency
Swift performance → /skill axiom-swift-performance
Synchronous actor access → /skill axiom-assume-isolated
Thread-safe primitives → /skill axiom-synchronization
Parameter ownership → /skill axiom-ownership-conventions
Concurrency profiling → /skill axiom-concurrency-profiling
User asks about concurrency
├─ Concurrency errors?
│ ├─ Data races? → swift-concurrency
│ ├─ Actor isolation? → swift-concurrency
│ ├─ @MainActor? → swift-concurrency
│ └─ Sendable? → swift-concurrency
│
├─ Writing async code? → swift-concurrency
│
├─ assumeIsolated questions? → assume-isolated
│
├─ Mutex/lock/synchronization? → synchronization
│
├─ borrowing/consuming/ownership? → ownership-conventions
│
├─ Profile async performance? → concurrency-profiling
│
└─ Performance optimization? → swift-performance
Swift 6 Concurrency (swift-concurrency):
Swift Performance (swift-performance):
User: "I'm getting 'data race' errors in Swift 6"
→ Invoke: /skill axiom-swift-concurrency
User: "How do I use @MainActor correctly?"
→ Invoke: /skill axiom-swift-concurrency
User: "My app is slow due to unnecessary copying"
→ Invoke: /skill axiom-swift-performance
User: "Should I use async/await for this network call?"
→ Invoke: /skill axiom-swift-concurrency
User: "How do I use assumeIsolated?"
→ Invoke: /skill axiom-assume-isolated
User: "My delegate callback runs on main thread, how do I access MainActor state?"
→ Invoke: /skill axiom-assume-isolated
User: "Should I use Mutex or actor?"
→ Invoke: /skill axiom-synchronization
User: "What's the difference between os_unfair_lock and OSAllocatedUnfairLock?"
→ Invoke: /skill axiom-synchronization
User: "What does borrowing do in Swift?"
→ Invoke: /skill axiom-ownership-conventions
User: "How do I use ~Copyable types?"
→ Invoke: /skill axiom-ownership-conventions
User: "My async code is slow, how do I profile it?"
→ Invoke: /skill axiom-concurrency-profiling
User: "I think I have actor contention, how do I diagnose it?"
→ Invoke: /skill axiom-concurrency-profiling
This skill should be used when the user asks to "create an agent", "add an agent", "write a subagent", "agent frontmatter", "when to use description", "agent examples", "agent tools", "agent colors", "autonomous agent", or needs guidance on agent structure, system prompts, triggering conditions, or agent development best practices for Claude Code plugins.
This skill should be used when the user asks to "create a slash command", "add a command", "write a custom command", "define command arguments", "use command frontmatter", "organize commands", "create command with file references", "interactive command", "use AskUserQuestion in command", or needs guidance on slash command structure, YAML frontmatter fields, dynamic arguments, bash execution in commands, user interaction patterns, or command development best practices for Claude Code.
This skill should be used when the user asks to "create a hook", "add a PreToolUse/PostToolUse/Stop hook", "validate tool use", "implement prompt-based hooks", "use ${CLAUDE_PLUGIN_ROOT}", "set up event-driven automation", "block dangerous commands", or mentions hook events (PreToolUse, PostToolUse, Stop, SubagentStop, SessionStart, SessionEnd, UserPromptSubmit, PreCompact, Notification). Provides comprehensive guidance for creating and implementing Claude Code plugin hooks with focus on advanced prompt-based hooks API.