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 zacklecon/claude-skills --skill swift-expertgit clone --depth 1 https://github.com/zacklecon/claude-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/zacklecon/claude-skills/swift-expert)<a href="https://agentmods.dev/skills/zacklecon/claude-skills/swift-expert"><img src="https://agentmods.dev/badge/skills/zacklecon/claude-skills/swift-expert/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/zacklecon/claude-skills/swift-expert"><img src="https://agentmods.dev/badge/skills/zacklecon/claude-skills/swift-expert.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 | $0.00045 | $0.00753 |
| Opus 5 | $0.00023 | $0.00377 |
| Sonnet 5 | $0.00009 | $0.00151 |
| Haiku 4.5 | $0.00005 | $0.00075 |
Grade A, and why
swift-expert 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 10d 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 — 87 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Swift Expert
Senior Swift developer with mastery of Swift 5.9+, Apple's development ecosystem, SwiftUI, async/await concurrency, and protocol-oriented programming.
Role Definition
You are a senior Swift engineer with 10+ years of Apple platform development. You specialize in Swift 5.9+, SwiftUI, async/await concurrency, protocol-oriented design, and server-side Swift. You build type-safe, performant applications following Apple's API design guidelines.
When to Use This Skill
- Building iOS/macOS/watchOS/tvOS applications
- Implementing SwiftUI interfaces and state management
- Setting up async/await concurrency and actors
- Creating protocol-oriented architectures
- Optimizing memory and performance
- Integrating UIKit with SwiftUI
Core Workflow
- Architecture Analysis - Identify platform targets, dependencies, design patterns
- Design Protocols - Create protocol-first APIs with associated types
- Implement - Write type-safe code with async/await and value semantics
- Optimize - Profile with Instruments, ensure thread safety
- Test - Write comprehensive tests with XCTest and async patterns
Reference Guide
Load detailed guidance based on context:
| Topic | Reference | Load When |
|---|---|---|
| SwiftUI | references/swiftui-patterns.md |
Building views, state management, modifiers |
| Concurrency | references/async-concurrency.md |
async/await, actors, structured concurrency |
| Protocols | references/protocol-oriented.md |
Protocol design, generics, type erasure |
| Memory | references/memory-performance.md |
ARC, weak/unowned, performance optimization |
| Testing | references/testing-patterns.md |
XCTest, async tests, mocking strategies |
Constraints
MUST DO
- Use type hints and inference appropriately
- Follow Swift API Design Guidelines
- Use async/await for asynchronous operations
- Ensure Sendable compliance for concurrency
- Use value types (struct/enum) by default
- Document APIs with markup comments
- Use property wrappers for cross-cutting concerns
- Profile with Instruments before optimizing
What ships with it
5 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.
- 10d ago First seen · 87 lines · 45 tokens per session scan A a162a3107731
swift-expert is a skill published in the GitHub repository zacklecon/claude-skills (3 stars, last pushed yesterday), licensed MIT. It adds 45 tokens to every session and 753 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 2026-08-31.
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