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 agentmods add skills/dev869/swift-tothemax/swift-languagenpx skills add Dev869/swift-tothemax --skill swift-languagegit clone --depth 1 https://github.com/Dev869/swift-tothemaxWrote 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/dev869/swift-tothemax/swift-language)<a href="https://agentmods.dev/skills/dev869/swift-tothemax/swift-language"><img src="https://agentmods.dev/badge/skills/dev869/swift-tothemax/swift-language.svg" alt="Measured on agentmods" 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 | $0.00167 | $0.02264 |
| Opus 5 | $0.00084 | $0.01132 |
| Sonnet 5 | $0.00033 | $0.00453 |
| Haiku 4.5 | $0.00017 | $0.00226 |
Grade A, and why
swift-language 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 6d 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.
How it starts
The opening of the file, as written. The whole thing — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Swift to the Max
Expert-level guidance for modern Swift. The goal: code that a senior Swift engineer in 2026 would write — strict-concurrency-clean, value-semantic by default, expressive at the type level, and honest about performance.
Version landscape (mid-2026)
| Version | Status | Headline features |
|---|---|---|
| Swift 5.10 | legacy | last 5.x; complete strict-concurrency checking under -strict-concurrency=complete |
| Swift 6.0 | 2024 | Swift 6 language mode (data-race safety by default), typed throws, count(where:), 128-bit ints |
| Swift 6.1 | 2025 | trailing commas everywhere, nonisolated on types/extensions, package traits |
| Swift 6.2 | 2025 | approachable concurrency: default MainActor isolation (opt-in), nonisolated(nonsending) / @concurrent, InlineArray, Span/MutableSpan, opt-in strict memory safety, Observations, backtraces on crash |
| Swift 6.3 | Mar 2026, current stable | @c attribute (expose Swift to C), official Android SDK, Swift Build preview in SwiftPM, @specialized / @inline(always), module selector syntax (ModuleName::Type), completed Embedded Swift feature set |
| Swift 6.4 | WWDC26 beta | await in defer, Iterable protocol (borrowing iteration), anyAppleOS availability shorthand, @diagnose, Swift Testing ↔ XCTest interop, unified URL implementation |
Default to Swift 6 language mode semantics unless the project's Package.swift / build settings say otherwise. Check // swift-tools-version: and swiftLanguageModes: before assuming. Never emit code using a beta-only (6.4) feature without flagging it as such.
Non-negotiable defaults
These apply to essentially all new Swift code; deviate only when the surrounding codebase clearly does otherwise, and say so.
- Value types first.
struct/enumunless you need identity, inheritance, or reference semantics. If you reach forclass, ask whether it should be anactororfinal class. - Strict concurrency clean. No
@unchecked Sendablewithout a written justification (a lock or immutability argument). NoDispatchQueuein new code — use actors,Task,TaskGroup,AsyncSequence,Mutex(Synchronization module, 6.0+). somebeforeany. Existentials (any P) cost dynamic dispatch and boxing; opaque types (some P) keep static dispatch. Useanyonly when you genuinely need heterogeneity.- Exhaustive
switchoverif-chains for enums; avoiddefault:when you can enumerate cases — it silences the compiler when new cases appear. - No force unwraps / force try in production paths.
!is acceptable only for programmer-error invariants, and then preferguard let ... else { preconditionFailure("why") }so the invariant is documented. - Typed throws (
throws(MyError)) for closed error domains (libraries, embedded); plainthrowsfor application-level composition. guardfor early exit, one happy path at low indentation.- API names follow the Swift API Design Guidelines — fluent at the call site, omit needless words (details in
references/api-design-and-errors.md).
What ships with it
9 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.
- evals/evals.json 5.4 KB
- references/api-design-and-errors.md 13 KB
- references/concurrency.md 13 KB
- references/interop-and-platforms.md 12 KB
- references/macros.md 10 KB
- references/memory-and-performance.md 13 KB
- references/swiftpm-and-tooling.md 11 KB
- references/testing.md 11 KB
- references/types-and-generics.md 11 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.
- 6d ago First seen · 98 lines · 167 tokens per session scan A 34b9278192cb
swift-language is a skill published in the GitHub repository Dev869/swift-tothemax (7 stars, last pushed 2mo ago), licensed MIT. It adds 167 tokens to every session and 2,264 once invoked, about $0.0008 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 2026-08-31.
Other skills, from other repositories
combine
Route Combine implementation tasks to the correct Knowledge Contracts -- the Publisher/Subscriber protocol pair, sink(receiveCompletion:receiveValue:)/sink(receiveValue:) and retaining the returned AnyCancellable; @Published/ObservableObject and the synthesized objectWillChange publisher; PassthroughSubject vs.…
swiftui
Route SwiftUI implementation tasks to the correct Knowledge Contracts — view composition, view identity in ForEach/List, modifier order, NavigationStack/NavigationPath, NavigationSplitView, stack/spacing layout, safe area handling, lazy grids/stacks, GeometryReader pitfalls, @State/@Binding, the @Observable macro…
foundation
Route Swift Foundation framework implementation tasks to the correct Knowledge Contracts -- date/time formatting, measurement and unit formatting, Codable encoding and custom conformance, and FileManager app sandbox directories. Use when working with DateFormatter, ISO8601DateFormatter, Date.FormatStyle, .formatted()…
generators
Code generator skills that produce production-ready Swift code for common app components. Use when user wants to add logging, analytics, onboarding, review prompts, networking, authentication, paywalls, settings, persistence, error monitoring, CI/CD pipelines, localization, push notifications, deep linking, testing…
attributed-string
AttributedString patterns for rich text formatting, alignment, selection, and SwiftUI integration. Use when working with styled text, text editing, or AttributedString APIs.
coding-best-practices
Reviews Swift/iOS code for adherence to modern Swift idioms, Apple platform best practices, architecture patterns, and code quality standards. Use when user mentions best practices, code review, clean code, refactoring, or wants to improve code quality.