# Swift Concurrency

> Swift concurrency: async/await, Actor, Task, Sendable patterns.

- **Type:** Skill
- **Install:** `agentstack add skill-notque-vexjoy-agent-swift-concurrency`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [notque](https://agentstack.voostack.com/s/notque)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [notque](https://github.com/notque)
- **Source:** https://github.com/notque/vexjoy-agent/tree/main/skills/engineering/swift-concurrency
- **Website:** https://vexjoy.com

## Install

```sh
agentstack add skill-notque-vexjoy-agent-swift-concurrency
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Swift Structured Concurrency

Pattern catalog for Swift's structured concurrency model: async/await, Actors, TaskGroups, AsyncSequence, Sendable, and cancellation. Load the reference file matching the developer's question.

## Reference Loading Table

| Signal | Reference File | Content |
|--------|---------------|---------|
| async/await, Task, Sendable | references/fundamentals.md | async/await patterns, Task/Task.detached, Sendable/@Sendable |
| Actor, @MainActor, nonisolated | references/actor-isolation.md | Actor isolation, MainActor UI confinement, nonisolated opt-out |
| TaskGroup, AsyncSequence, AsyncStream, cancellation | references/task-patterns.md | Structured concurrency, rate-limited groups, streams, cancellation |
| Failure modes, common mistakes | references/preferred-patterns.md | Blocking MainActor, task leaking, actor reentrancy hazard |

## Key Conventions

- **Prefer structured concurrency** -- use `TaskGroup` over loose `Task { }` whenever possible; structured tasks propagate cancellation and errors automatically.
- **Mark types Sendable** -- enable strict concurrency checking (`-strict-concurrency=complete`) and resolve all warnings before they become errors in Swift 6.
- **Use actors for shared mutable state** -- avoid manual locks; actors provide compiler-verified safety.
- **Cancel what you create** -- every `Task` stored in a property should have a corresponding cancellation path.
- **Minimize @MainActor surface** -- isolate only the UI layer; keep business logic and networking off the main actor.

## References

- `references/fundamentals.md` -- async/await, Task, Sendable basics
- `references/actor-isolation.md` -- Actor, @MainActor, nonisolated
- `references/task-patterns.md` -- TaskGroup, AsyncSequence, AsyncStream, cancellation
- `references/preferred-patterns.md` -- blocking, leaking, reentrancy mistakes

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [notque](https://github.com/notque)
- **Source:** [notque/vexjoy-agent](https://github.com/notque/vexjoy-agent)
- **License:** MIT
- **Homepage:** https://vexjoy.com

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-notque-vexjoy-agent-swift-concurrency
- Seller: https://agentstack.voostack.com/s/notque
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.