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 patrickserrano/lacquer --skill swift-concurrencygit clone --depth 1 https://github.com/patrickserrano/lacquerWrote 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/patrickserrano/lacquer/swift-concurrency)<a href="https://agentmods.dev/skills/patrickserrano/lacquer/swift-concurrency"><img src="https://agentmods.dev/badge/skills/patrickserrano/lacquer/swift-concurrency/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/patrickserrano/lacquer/swift-concurrency"><img src="https://agentmods.dev/badge/skills/patrickserrano/lacquer/swift-concurrency.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 | $0.00158 | $0.02466 |
| Opus 5.5 | $0.00063 | $0.00986 |
| Sonnet 5.5 | $0.00032 | $0.00493 |
| Haiku 4.5 | $0.00016 | $0.00247 |
Grade A, and why
swift-concurrency 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 1mo 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.
This is a copy
80% identical to swift-concurrency — 54 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 174 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Swift Concurrency
Fast Path
Before proposing a fix:
- Analyze
Package.swiftor.pbxprojto determine Swift language mode, strict concurrency level, default isolation, and upcoming features. Do this always, not only for migration work. - Capture the exact diagnostic and offending symbol.
- Determine the isolation boundary:
@MainActor, custom actor, actor instance isolation, ornonisolated. - Confirm whether the code is UI-bound or intended to run off the main actor. For delayed retries, timers, and backoff tasks, separate the waiting from the UI mutation. The sleep often belongs off the main actor even when the final state update belongs on it.
Project settings that change concurrency behavior:
| Setting | SwiftPM (Package.swift) |
Xcode (.pbxproj) |
|---|---|---|
| Language mode | swiftLanguageVersions or -swift-version (// swift-tools-version: is not a reliable proxy) |
Swift Language Version |
| Strict concurrency | .enableExperimentalFeature("StrictConcurrency=targeted") |
SWIFT_STRICT_CONCURRENCY |
| Default isolation | .defaultIsolation(MainActor.self) |
SWIFT_DEFAULT_ACTOR_ISOLATION |
| Upcoming features | .enableUpcomingFeature("NonisolatedNonsendingByDefault") |
SWIFT_UPCOMING_FEATURE_* |
If any of these are unknown, ask the developer to confirm them before giving migration-sensitive guidance. Do not guess.
Guardrails:
- Do not recommend
@MainActoras a blanket fix. Justify why the code is truly UI-bound. - Prefer structured concurrency over unstructured tasks. Use
Task.detachedonly with a clear reason. - If recommending
@preconcurrency,@unchecked Sendable, ornonisolated(unsafe), require a documented safety invariant and a follow-up removal plan. - Optimize for the smallest safe change. Do not refactor unrelated architecture during migration.
- Course references are for deeper learning only. Use them sparingly and only when they clearly help answer the developer's question.
Quick Fix Mode
Use Quick Fix Mode when all of these are true:
What ships with it
15 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.
- references/_index.md 1.9 KB
- references/actors.md 14 KB
- references/async-algorithms.md 20 KB
- references/async-await-basics.md 6.4 KB
- references/async-sequences.md 16 KB
- references/core-data.md 14 KB
- references/glossary.md 6.7 KB
- references/linting.md 5.2 KB
- references/memory-management.md 12 KB
- references/migration.md 30 KB
- references/performance.md 12 KB
- references/sendable.md 11 KB
- references/tasks.md 13 KB
- references/testing.md 13 KB
- references/threading.md 12 KB
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.
- 1mo ago First seen · 174 lines · 158 tokens per session scan A f20c62bdbbf2
swift-concurrency is a skill published in the GitHub repository patrickserrano/lacquer (5 stars, last pushed yesterday), licensed MIT. It adds 158 tokens to every session and 2,466 once invoked, about $0.0006 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 80% identical to swift-concurrency, differing in 54 lines, and is treated as a copy.
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