swift-concurrency

swift-concurrency is a skill for Claude Code, Codex from AFK-surf/OpenBridge. It costs 139 tokens per session (2,577 once invoked), scanned A, original, MIT.

Expert guidance for Swift Concurrency, including async/await, actors, tasks, Sendable values, and migration to Swift 6. Swift Concurrency is Swift’s built-in approach to running asynchronous work safely.

In plain words
What is it for?
Use it when writing or reviewing async code, using actors or tasks, fixing thread-safety issues, migrating to Swift 6, or refactoring callback-based asynchronous code.
Why use it?
It helps developers reason about which code may run together and how to protect shared data from data races. It favors structured task patterns and requires justification for unsafe escape hatches.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

Good fit Use it when writing or reviewing async code, using actors or tasks, fixing thread-safety issues, migrating to Swift 6, or refactoring callback-based asynchronous code.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/afk-surf/openbridge/swift-concurrency
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 AFK-surf/OpenBridge --skill swift-concurrency
Clone the repo
git clone --depth 1 https://github.com/AFK-surf/OpenBridge

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

README.md
[![agentmods](https://agentmods.dev/badge/skills/afk-surf/openbridge/swift-concurrency.svg)](https://agentmods.dev/skills/afk-surf/openbridge/swift-concurrency)
Your own site
<a href="https://agentmods.dev/skills/afk-surf/openbridge/swift-concurrency"><img src="https://agentmods.dev/badge/skills/afk-surf/openbridge/swift-concurrency.svg" alt="Measured on agentmods" height="20"></a>
Per session 139 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,577 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found 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 $0.00139 $0.02577
Opus 5 $0.00069 $0.01288
Sonnet 5 $0.00028 $0.00515
Haiku 4.5 $0.00014 $0.00258

Measured 9d ago against content hash 62e81a46dc20, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

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 9d 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

Copies of this mod

2 near-identical copies found in the catalogue:

.agents/skills/swift-concurrency/SKILL.md · 247 lines

How it starts

The opening of the file, as written. The whole thing — 247 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Swift Concurrency

Overview

This skill provides expert guidance on Swift Concurrency, covering modern async/await patterns, actors, tasks, Sendable conformance, and migration to Swift 6. Use this skill to help developers write safe, performant concurrent code and navigate the complexities of Swift's structured concurrency model.

Agent Behavior Contract (Follow These Rules)

  1. Analyze the project/package file to find out which Swift language mode (Swift 5.x vs Swift 6) and which Xcode/Swift toolchain is used when advice depends on it.
  2. Before proposing fixes, identify the isolation boundary: @MainActor, custom actor, actor instance isolation, or nonisolated.
  3. Do not recommend @MainActor as a blanket fix. Justify why main-actor isolation is correct for the code.
  4. Prefer structured concurrency (child tasks, task groups) over unstructured tasks. Use Task.detached only with a clear reason.
  5. If recommending @preconcurrency, @unchecked Sendable, or nonisolated(unsafe), require:
    • a documented safety invariant
    • a follow-up ticket to remove or migrate it
  6. For migration work, optimize for minimal blast radius (small, reviewable changes) and add verification steps.
  7. Course references are for deeper learning only. Use them sparingly and only when they clearly help answer the developer's question.

When analyzing Swift projects for concurrency issues:

  1. Project Settings Discovery
    • Use Read on Package.swift for SwiftPM settings (tools version, strict concurrency flags, upcoming features)
    • Use Grep for SWIFT_STRICT_CONCURRENCY or SWIFT_DEFAULT_ACTOR_ISOLATION in .pbxproj files
    • Use Grep for SWIFT_UPCOMING_FEATURE_ to find enabled upcoming features

Project Settings Intake (Evaluate Before Advising)

Concurrency behavior depends on build settings. Always try to determine:

  • Default actor isolation (is the module default @MainActor or nonisolated?)
  • Strict concurrency checking level (minimal/targeted/complete)
  • Whether upcoming features are enabled (especially NonisolatedNonsendingByDefault)
  • Swift language mode (Swift 5.x vs Swift 6) and SwiftPM tools version

Read the full file on GitHub · 247 lines

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. 9d ago First seen · 247 lines · 139 tokens per session scan A 62e81a46dc20

Subscribe to this mod's changes

swift-concurrency is a skill published in the GitHub repository AFK-surf/OpenBridge (428 stars, last pushed 3mo ago), licensed MIT. It adds 139 tokens to every session and 2,577 once invoked, about $0.0007 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 2026-08-30.

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