Skip to content
Get packs

Swift Concurrency Expert

Diagnoses and fixes Swift 6.2 concurrency compiler errors, Sendable and actor isolation issues.

Source Download skill
Repository
steipete/agent-scripts
Stars
7,433
Licence
MIT
Files
3 files

What it does

Swift has rules that stop code from running into data races when work happens on several threads at once. When this skill is installed, the agent follows a structured process for fixing those compiler errors: it captures the exact diagnostic, checks which actor (such as the main UI thread) the code belongs to, and then applies the smallest change that keeps behavior the same. It also has reference notes on Swift 6.2 concurrency changes and SwiftUI concurrency guidance to consult.

Great for

  • Swift developers hitting 'Sendable' or actor isolation errors after moving to Swift 6 or 6.2
  • Teams migrating an existing app to strict concurrency checking who want consistent, minimal fixes
  • Developers who want an agent to explain why a fix is needed, not just silence the compiler

Skip it if

  • Projects not using Swift (for example JavaScript or Python), where none of this applies
  • Blindly suppressing warnings with @unchecked Sendable: the skill itself warns against this unless thread safety can be proven, so review any such change carefully
  • Non-Swift-6.2 codebases where the advice on newer @concurrent patterns may not compile

Try asking

  • “Fix this compiler error: 'non-sendable type cannot be sent across actor boundaries' in my ViewModel”
  • “Make my settings store main-actor isolated without changing its public behavior”
  • “Move this expensive image-processing function off the main actor using the Swift 6.2 approach”
  • “Review my Swift package for Sendable issues and propose the smallest safe fixes”
Step-by-step guide: how to use Swift Concurrency ExpertInstall, first run, examples, tips and FAQs

Install in 3 steps

  1. 1

    Download the skill

    The ZIP contains the 3 original files, the MIT licence and an attribution note.

    swift-concurrency-expert.zip
  2. 2

    Add it to your agent

    Claude Code (all projects)

    mkdir -p ~/.claude/skills && unzip swift-concurrency-expert.zip -d ~/.claude/skills/

    Claude Code / Agent SDK (this project only)

    mkdir -p .claude/skills && unzip swift-concurrency-expert.zip -d .claude/skills/

    Claude apps (web/desktop): Settings → Capabilities → Skills → Upload skill, and choose the ZIP.

  3. 3

    Ask for the task

    No special command needed — the agent reads the skill's description and loads it when your request matches. Try one of the prompts above.

Get better results

  • Paste the exact compiler diagnostic and the code around the flagged symbol so the agent can triage correctly.
  • Say whether your project enables default main-actor isolation, since the skill asks about it and it changes the right fix.
  • Review each proposed change in your own compiler and test suite, because the skill is guidance and does not run or verify builds itself.

What's inside

  • references/swift-6-2-concurrency.md
  • references/swiftui-concurrency-tour-wwdc.md
  • SKILL.md

Redistributed unmodified from steipete/agent-scripts under the MIT licence. The assessment was drafted with AI from the skill's files on 2026-10-29. Skills can instruct your agent to run code — read SKILL.md and any scripts before installing.