swift-concurrency-expert

swift-concurrency-expert is a skill for Claude Code, Codex from dagba/ios-mcp. It costs 45 tokens per session (485 once invoked), scanned A, a copy of swift-concurrency-expert, MIT.

A review and repair guide for Swift Concurrency in Swift 6.2 and newer, the tools Swift uses to run work safely at the same time.

In plain words
What is it for?
Use it to review actor isolation, Sendable safety, main-thread UI code, background work, and concurrency-related compiler diagnostics.
Why use it?
It helps resolve compiler errors and prevent different parts of an app from changing shared data unsafely at once.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to review actor isolation, Sendable safety, main-thread UI code, background work, and concurrency-related compiler diagnostics.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/dagba/ios-mcp/swift-concurrency-expert
Install

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.

Any agent
npx skills add dagba/ios-mcp --skill swift-concurrency-expert
Clone the repo
git clone --depth 1 https://github.com/dagba/ios-mcp

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for swift-concurrency-expert

README.md
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Your own site
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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.

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Your own site · 80×15
<a href="https://agentmods.dev/skills/dagba/ios-mcp/swift-concurrency-expert"><img src="https://agentmods.dev/badge/skills/dagba/ios-mcp/swift-concurrency-expert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 45 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 485 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 91% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00045 $0.00485
Opus 5 $0.00023 $0.00243
Sonnet 5 $0.00009 $0.00097
Haiku 4.5 $0.00005 $0.00049

Measured 10d ago against content hash 40d2ce2321b7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

swift-concurrency-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.

Origin

This is a copy

91% identical to swift-concurrency-expert — 1 line 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.

skills/swift-concurrency-expert/SKILL.md · 39 lines

What it actually says

Swift Concurrency Expert

Overview

Review and fix Swift Concurrency issues in Swift 6.2+ codebases by applying actor isolation, Sendable safety, and modern concurrency patterns with minimal behavior changes.

Workflow

1. Triage the issue

  • Capture the exact compiler diagnostics and the offending symbol(s).
  • Check project concurrency settings: Swift language version (6.2+), strict concurrency level, and whether approachable concurrency (default actor isolation / main-actor-by-default) is enabled.
  • Identify the current actor context (@MainActor, actor, nonisolated) and whether a default actor isolation mode is enabled.
  • Confirm whether the code is UI-bound or intended to run off the main actor.

2. Apply the smallest safe fix

Prefer edits that preserve existing behavior while satisfying data-race safety.

Common fixes:

  • UI-bound types: annotate the type or relevant members with @MainActor.
  • Protocol conformance on main actor types: make the conformance isolated (e.g., extension Foo: @MainActor SomeProtocol).
  • Global/static state: protect with @MainActor or move into an actor.
  • Background work: move expensive work into a @concurrent async function on a nonisolated type or use an actor to guard mutable state.
  • Sendable errors: prefer immutable/value types; add Sendable conformance only when correct; avoid @unchecked Sendable unless you can prove thread safety.

Reference material

  • See references/swift-6-2-concurrency.md for Swift 6.2 changes, patterns, and examples.
  • See references/approachable-concurrency.md when the project is opted into approachable concurrency mode.
  • See references/swiftui-concurrency-tour-wwdc.md for SwiftUI-specific concurrency guidance.
  • See references/Swift-Concurrency-Updates.md for official Apple documentation on Swift 6.2 data-race safety, Approachable Concurrency, and default actor isolation patterns.
Files

What ships with it

4 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.

Changes

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.

  1. 10d ago First seen · 39 lines · 45 tokens per session scan A 40d2ce2321b7

Subscribe to this mod's changes

swift-concurrency-expert is a skill published in the GitHub repository dagba/ios-mcp (3 stars, last pushed 7mo ago), licensed MIT. It adds 45 tokens to every session and 485 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 91% identical to swift-concurrency-expert, differing in 1 line, and is treated as a copy.

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