Ios Simulator Browser Skill for Codex
Mirror an iOS Simulator into the Codex in-app browser and render SwiftUI previews from importable Swift packages in that simulator with hot reload. Use when a user wants to watch or interact with an iOS app in the browser, see a SwiftUI preview outside Xcode Canvas, iterate live on a preview, or capture browser-visible simulator proof.
Install
one command, takes just this skill from the repositorynpx skills add https://github.com/openai/plugins --skill ios-simulator-browserWhat comes with it
67 163 bytes besides the instructionThe instruction itself
5 sections, as written by the authoriOS Simulator Browser
Browser Workflow
- Obtain an explicit Simulator UDID from the existing iOS build/run workflow or from
xcrun simctl list devices available. - Start
serve-simin a long-running terminal pinned to that simulator. Clean up any tracked stale helper for this simulator before starting, and install a trap so the helper is cleaned up when this terminal exits:
SIM="<simulator-udid>"
cleanup_serve_sim() {
npx --yes serve-sim@latest --kill "$SIM" >/dev/null 2>&1 || true
}
trap cleanup_serve_sim EXIT INT TERM HUP
cleanup_serve_sim
npx --yes serve-sim@latest "$SIM"
- Open the exact local preview URL printed by
serve-simin the Codex in-app browser. - Verify that a real frame is rendering before reporting success. A loaded page alone is not proof that the simulator stream is healthy.
- Keep the terminal alive while the browser mirror is in use. When finished, stop the terminal and wait for it to exit so the trap runs.
- If the terminal disappeared or did not exit cleanly, run
npx --yes serve-sim@latest --kill "$SIM"before starting another mirror for that simulator. - Never run an unscoped
serve-sim --kill; another thread may own a different simulator mirror.
SwiftUI Preview Workflow
Use the bundled launcher when the requested previews live in an importable Swift package. Point it at the package manifest and select the target whose previews should be displayed. It generates a disposable host project outside the user's source tree, installs and launches that host in Simulator, and watches the package for edits.
node <skill-root>/scripts/swiftui-preview-browser.mjs \
/absolute/path/to/Package.swift \
--package-target "<target>" \
--device "<simulator-udid>"
- Watch mode is enabled by default. On a Swift package source edit, the launcher rebuilds a generated dylib and hot-swaps it into the running host without relaunching the app.
- The generated host shows every preview variant discovered in the selected Swift Package target with in-simulator page controls. To show a subset instead, pass
--preview-filter <regex[, ...]>; it matches display names and code identifiers such asStatusRowView_Previews. - Once the launcher prints the selected Simulator UDID, start
serve-simfor that same UDID and open its printed URL in the in-app browser.
Support Boundary
- Support Swift Package-backed
PreviewProviderand#Previewdeclarations through the generated host. - Do not edit the user's
.xcodeproj,.xcworkspace,Package.swift, schemes, or build settings to force preview support.
Proof
For browser or preview QA, capture a browser screenshot showing the simulator frame. For hot reload QA, also report the launcher's hot reloaded package preview ... in pid ... output and show the changed frame after editing.
Other skills for the same job
different authors, same section of the catalogue
Annotate UI screenshots with documentation callouts in Fellyph's established visual style — uniform-width orange arrows with white halos, double-stroke target outlines, numbered callout cards, dim overlays and a framed canvas. Use this whenever the user asks to annotate a screenshot, add arrows or callouts to a screenshot, create documentation images, highlight UI controls in a capture, or produce docs/tutorial visuals for Playground, Studio or any web UI — even if they just say "add arrows to this" or "make a docs screenshot".
Render pixel-accurate iMessage screenshot mockups (DM or group) from a thread JSON. Supports minimal, with-keyboard, and full iPhone 15 Pro frame variants. Outputs HTML + PNG.
> End-to-end skill that turns a single reference image into a published Gooseworks style — analyzes the image, drafts the slim style spec, renders a hero example plus 2-3 additional formats via Playwright, writes the `gooseworks-style.json` manifest, and publishes via `npx gooseworks styles publish` so other agents can discover it. Mirrors goose-graphics-create-format but for styles.
Resize and validate App Store screenshots with current asc screenshot-size data and macOS sips. Use when preparing or fixing screenshots for App Store Connect submission.
Generates an automated App Store screenshot pipeline with UI tests for screenshot capture, device framing, localized caption overlays, and multi-size batch export. Use when user wants automated screenshots, App Store screenshot generation, or a fastlane snapshot replacement.
Dependency checker and installer for agent-canvas, agent-eyes, and canvas-edit skills. Use BEFORE running any canvas skill for the first time, or when canvas skills fail with import/browser errors. Triggers on "setup agent canvas", "install canvas dependencies", "canvas not working", "playwright not found", or any setup/installation request for canvas skills.
Generate high-density editorial HTML info cards in a modern magazine and Swiss-international style, then capture them as ratio-specific screenshots. Use when the user provides text or core information and wants: (1) a complete responsive HTML info card, (2) the design to follow the stored editorial prompt, (3) output in fixed visual ratios such as 3:4, 4:3, 1:1, 16:9, 9:16, 2.35:1, 3:1, or 5:2, or (4) both HTML and a rendered PNG cover/card from the same content.
Expert blueprint for HTML5/web export on Compatibility (WebGL 2.0): JavaScriptBridge, localStorage wrapper, custom loading shells, COOP/COEP hosts, relative paths, beforeunload, visibility pause, and size optimization. WebGPU is out of scope. Keywords: web, HTML5, WebGL, Compatibility, JavaScriptBridge, localStorage, COOP, COEP, canvas, browser API.
How to use it
Take openai/ios-simulator-browser from the repository into ~/.claude/skills for personal
use, or into .claude/skills inside a project.
The agent identifies a skill by the name field in its header. Two skills with the
same name cannot sit side by side — one of them will be ignored.
The instructions reference npx.
Without those the skill loads but fails at the first command.