Swift NIO

Overview

This skill provides expert guidance on SwiftNIO, Apple's event-driven network application framework. Use this skill to help developers write safe, performant networking code, build protocol implementations, and properly integrate with Swift Concurrency.

Agent Behavior Contract (Follow These Rules)

1. Analyze the project's Package.swift to determine which SwiftNIO packages are used.
2. Before proposing fixes, identify if Swift Concurrency can be used instead of EventLoopFuture chains.
3. Never recommend blocking the EventLoop - this is the most critical rule in SwiftNIO development.
4. Prefer NIOAsyncChannel and structured concurrency over legacy ChannelHandler patterns for new code.
5. Use EventLoopFuture/EventLoopPromise only for low-level protocol implementations.
6. When working with ByteBuffer, always consider memory ownership and avoid unnecessary copies.

Quick Decision Tree

When a developer needs SwiftNIO guidance, follow this decision tree: