Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add memi-design/design-skills --skill swift-concurrency-safetygit clone --depth 1 https://github.com/memi-design/design-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/memi-design/design-skills/swift-concurrency-safety)<a href="https://agentmods.dev/skills/memi-design/design-skills/swift-concurrency-safety"><img src="https://agentmods.dev/badge/skills/memi-design/design-skills/swift-concurrency-safety/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/memi-design/design-skills/swift-concurrency-safety"><img src="https://agentmods.dev/badge/skills/memi-design/design-skills/swift-concurrency-safety.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00034 | $0.00313 |
| Opus 5 | $0.00017 | $0.00156 |
| Sonnet 5 | $0.00007 | $0.00063 |
| Haiku 4.5 | $0.00003 | $0.00031 |
Grade A, and why
swift-concurrency-safety scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Swift Concurrency Safety
Use this skill for async features, Swift 6 migration, actor-isolation errors, Sendable warnings, task cancellation, or UI work that crosses concurrency domains.
Workflow
- Record the target's Swift language mode and concurrency-checking settings.
- Map mutable state and its owner before adding tasks or annotations.
- Keep UI state on the main actor. Move long-running work behind async service boundaries instead of blocking the actor.
- Prefer structured child tasks. Use detached or unstructured tasks only when lifetime and cancellation are explicitly owned.
- Pass immutable Sendable values across isolation boundaries. Do not hide warnings with unchecked conformance until invariants are documented and tested.
- Propagate cancellation and define what partial work is rolled back or retained.
- Compile with the project's strictest supported concurrency checks and test ordering, cancellation, failure, and reentrancy.
Review failures
- Actor annotations added only to silence diagnostics.
Task {}used as an ownership escape hatch.- UI-observable models mutated off the main actor.
- Mutable reference types crossing actors without an isolation plan.
- Continuations that can resume twice or never resume.
- Async APIs with no cancellation or timeout behavior.
Read references/migration.md before changing language mode or performing a broad migration.
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago First seen · 30 lines · 34 tokens per session scan A c223be2d4604
swift-concurrency-safety is a skill published in the GitHub repository memi-design/design-skills (7 stars, last pushed 1mo ago), licensed MIT. It adds 34 tokens to every session and 313 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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