guide-swift-concurrency
Swift concurrency patterns — actors, structured concurrency, cancellation, async streams, GCD migration, strict-concurrency diagnostics, common bug patterns. Use when writing, reviewing, or debugging concurrent Swift code.
- Installs
- 449
- Last 24h
- +13
- Trending rank
- #7568
- Security
- Not audited
Install
Works with every agent the skills CLI supports.
npx skills add https://github.com/prisma-labs-dev/apple-skills --skill guide-swift-concurrency- 01
Install
Run the command in your project. The CLI asks which agents to install for.
- 02
Describe the task
Ask your agent for something this skill covers. It loads guide-swift-concurrency automatically when relevant.
- 03
Review the result
The agent follows the SKILL.md steps, scripts and references bundled with the skill.
SKILL.md
The instructions your agent reads when the skill is triggered.
Guide Skill — This is an expert workflow/pattern guide, not API reference documentation. Originally from twostraws/Swift-Concurrency-Agent-Skill by Paul Hudson. MIT License.
Swift Concurrency Patterns
Review and write Swift concurrency code for correctness, modern API usage, and adherence to project conventions. Report only genuine problems — do not nitpick or invent issues.
Core Instructions
- Target Swift 6.2 or later with strict concurrency checking.
- Prefer structured concurrency (task groups) over unstructured (
Task {}). - Prefer Swift concurrency over GCD for new code. GCD is still acceptable in low-level code, framework interop, or performance-critical synchronous work.
- Do not suggest
@unchecked Sendableto fix compiler errors — prefer actors, value types, orsendingparameters.
Review Process
- Scan for known-dangerous patterns using
references/hotspots.md. - Check for Swift 6.2 concurrency behavior using
references/new-features.md. - Validate actor usage for reentrancy and isolation using
references/actors.md. - Ensure structured concurrency is preferred using
references/structured.md. - Check unstructured task usage using
references/unstructured.md. - Verify cancellation handling using
references/cancellation.md. - Validate async stream and continuation usage using
references/async-streams.md. - Check bridging code between sync and async using
references/bridging.md. - Review legacy concurrency migrations using
references/interop.md. - Cross-check against common failure modes using
references/bug-patterns.md. - If strict-concurrency errors exist, map diagnostics to fixes using
references/diagnostics.md. - If reviewing tests, check async test patterns using
references/testing.md.
If doing partial work, load only the relevant reference files.
References
| Topic | Reference |
|---|---|
| Grep targets for code review — known-dangerous patterns | references/hotspots.md |
Swift 6.2: default isolation, @concurrent, Task.immediate, isolated deinit | references/new-features.md |
| Actor reentrancy, global actor inference, isolation patterns | references/actors.md |
Task groups, async let, withDiscardingTaskGroup, concurrency limits | references/structured.md |
Task vs Task.detached, when Task {} is a code smell | references/unstructured.md |
Cooperative cancellation, withTaskCancellationHandler, broken patterns | references/cancellation.md |
AsyncStream.makeStream(of:), continuation lifecycle, back-pressure | references/async-streams.md |
Checked continuations, wrapping delegates, @unchecked Sendable | references/bridging.md |
| GCD migration, Combine to AsyncSequence, completion handlers, locks | references/interop.md |
| Common concurrency failure modes LLMs produce and their fixes | references/bug-patterns.md |
| Strict-concurrency compiler errors mapped to likely fixes | references/diagnostics.md |
| Async test patterns, race detection, avoiding timing-based tests | references/testing.md |
FAQ
What does the guide-swift-concurrency skill do?
Swift concurrency patterns — actors, structured concurrency, cancellation, async streams, GCD migration, strict-concurrency diagnostics, common bug patterns. Use when writing, reviewing, or debugging concurrent Swift code.
How do I install guide-swift-concurrency?
Run npx skills add https://github.com/prisma-labs-dev/apple-skills --skill guide-swift-concurrency in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/guide-swift-concurrency/ (personal) or .claude/skills/guide-swift-concurrency/ (project).
Which AI agents can use guide-swift-concurrency?
Any agent that supports the open Agent Skills format (a folder with a SKILL.md file), including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf, Cline, OpenCode and more.
Is guide-swift-concurrency safe to install?
No partner security audit is available yet. Skills can run commands and scripts, so read the SKILL.md and any bundled files before installing.
Who maintains guide-swift-concurrency?
It is published by prisma-labs-dev in prisma-labs-dev/apple-skills. It has 449 recorded installs.
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