serve-sim — Apple Simulator Hosting Tool

Skill by ara.so — Daily 2026 Skills collection.

serve-sim is the npx serve of Apple Simulators. It spawns a Swift helper that captures a booted iOS Simulator's framebuffer via simctl io, exposes it as an MJPEG stream + WebSocket control channel, and serves a React preview UI in your browser. Works with any booted iOS Simulator — no Xcode plugin, no app instrumentation required.

Requirements

• macOS with Xcode command line tools installed (xcrun simctl must be available)
• At least one booted iOS Simulator
• Node.js / npm (for npx)

Quick Start

# Start preview server (auto-detects booted simulator)
npx serve-sim
# → Preview at http://localhost:3200