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 The-Artificer-of-Ciphers-LLC/skills-from-the-artificer --skill swift-concurrencygit clone --depth 1 https://github.com/The-Artificer-of-Ciphers-LLC/skills-from-the-artificerWrote 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/the-artificer-of-ciphers-llc/skills-from-the-artificer/swift-concurrency)<a href="https://agentmods.dev/skills/the-artificer-of-ciphers-llc/skills-from-the-artificer/swift-concurrency"><img src="https://agentmods.dev/badge/skills/the-artificer-of-ciphers-llc/skills-from-the-artificer/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/the-artificer-of-ciphers-llc/skills-from-the-artificer/swift-concurrency"><img src="https://agentmods.dev/badge/skills/the-artificer-of-ciphers-llc/skills-from-the-artificer/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 | $0.00056 | $0.02839 |
| Opus 5.5 | $0.00022 | $0.01136 |
| Sonnet 5.5 | $0.00011 | $0.00568 |
| Haiku 4.5 | $0.00006 | $0.00284 |
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 12d 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
100% identical to swift-concurrency — 2 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 — 210 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. When spawning unstructured tasks, inspect the synchronous prefix (everything before the first
await): start on@MainActoronly when that prefix truly needs main-actor access; otherwise useTask { @concurrent in ... }and hop back withMainActor.runonly after the suspension. A trivial non-main line (for example,print) followed by main-actor work in the same prefix is not a reason to use@concurrent. 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_* |
| Approachable Concurrency | N/A (use individual upcoming features) | SWIFT_APPROACHABLE_CONCURRENCY |
Xcode 26 note: New projects created in Xcode 26 will often start with
SWIFT_DEFAULT_ACTOR_ISOLATION = MainActorandSWIFT_APPROACHABLE_CONCURRENCY = YESenabled by default. Treat these as likely defaults for newly created projects, not as confirmed settings.
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 17 KB
- references/async-algorithms.md 20 KB
- references/async-await-basics.md 7.5 KB
- references/async-sequences.md 17 KB
- references/core-data.md 15 KB
- references/glossary.md 6.9 KB
- references/linting.md 5.2 KB
- references/memory-management.md 12 KB
- references/migration.md 33 KB
- references/performance.md 15 KB
- references/sendable.md 13 KB
- references/tasks.md 17 KB
- references/testing.md 13 KB
- references/threading.md 16 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.
- 12d ago First seen · 210 lines · 56 tokens per session scan A a84a3874320a
swift-concurrency is a skill published in the GitHub repository The-Artificer-of-Ciphers-LLC/skills-from-the-artificer (6 stars, last pushed yesterday), licensed MIT. It adds 56 tokens to every session and 2,839 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to swift-concurrency, differing in 2 lines, and is treated as a copy.
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