# Kotlin Coroutines

> Kotlin structured concurrency, Flow, and Channel patterns.

- **Type:** Skill
- **Install:** `agentstack add skill-notque-vexjoy-agent-kotlin-coroutines`
- **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/kotlin-coroutines
- **Website:** https://vexjoy.com

## Install

```sh
agentstack add skill-notque-vexjoy-agent-kotlin-coroutines
```

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

## About

# Kotlin Coroutines Patterns

Umbrella skill for Kotlin coroutine development: structured concurrency, cancellation,
Flow, StateFlow/SharedFlow, Channels, exception handling, and dispatchers. Routes to
the correct reference based on the task at hand.

## Reference Loading Table

| Signal | Load These Files | Why |
|---|---|---|
| Concurrency | `concurrency-patterns.md` | Scopes, cancellation, dispatchers, exception handling |
| Flow | `flow-patterns.md` | Flow builders, StateFlow, SharedFlow, operators |
| Channels | `channel-patterns.md` | Producer-consumer, fan-in/fan-out patterns |
| Failure modes | `preferred-patterns.md` | GlobalScope, unstructured launch, CancellationException |

## Instructions

### Step 1: Identify the Domain

Classify the task into one or more domains, then load the corresponding reference files.
Only load what is needed -- do not load all references for every task.

| Domain | Load Reference | When |
|--------|---------------|------|
| Concurrency | `references/concurrency-patterns.md` | Scopes, cancellation, dispatchers, exception handling |
| Flow | `references/flow-patterns.md` | Flow builders, StateFlow, SharedFlow, operators |
| Channels | `references/channel-patterns.md` | Producer-consumer, fan-in/fan-out patterns |
| Failure modes | `references/preferred-patterns.md` | GlobalScope, unstructured launch, CancellationException |

Multiple domains may apply. For example, reviewing code that uses both Flow and Channels
should load both `flow-patterns.md` and `channel-patterns.md`.

### Step 2: Load and Follow the Reference

Read the selected reference file(s) using `${CLAUDE_SKILL_DIR}/references/.md`.
Each reference contains the full patterns, code examples, and decision matrices for that
domain. Follow the instructions in the reference as if they were this skill's instructions.

### Step 3: Execute

Apply the loaded reference patterns to the task. Use the code examples as templates
for implementation guidance.

## Key Principles

1. **Structured concurrency is non-negotiable** -- every coroutine must have a parent scope that defines its lifetime.
2. **Inject dispatchers** -- accept `CoroutineDispatcher` as a parameter so callers (and tests) can control threading.
3. **Always rethrow CancellationException** -- rethrow it immediately or use specific exception types instead of catching `Exception`.
4. **Prefer Flow over Channel** -- Flow is cold, composable, and handles backpressure. Channels are lower-level; reach for them only when Flow cannot express the pattern.
5. **Use supervisorScope for partial failure tolerance** -- when independent tasks should not cancel each other, wrap them in supervisorScope.
6. **Use scoped coroutines instead of GlobalScope** -- it has no lifecycle, no cancellation, and no structured concurrency. Pass a scope from your application framework instead.

## 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-kotlin-coroutines
- 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%.