# How to Create SwiftUI iOS Development Plugins with the Build‑iOS‑Apps Plugin > Learn to build SwiftUI iOS development plugins using the OpenAI build-ios-apps plugin. Scaffold refactor and debug your apps within a Codex workflow. - Repository: [OpenAI/plugins](https://github.com/openai/plugins) - Tags: how-to-guide - Published: 2026-06-07 --- **The Build‑iOS‑Apps plugin in the `openai/plugins` repository is a modular Codex skill set that lets you scaffold, refactor, and debug SwiftUI iOS apps without leaving a Codex-driven workflow.** If you want to create SwiftUI iOS development plugins with the Build‑iOS‑Apps toolkit, start with the `openai/plugins` repo. It bundles discrete skills for UI patterns, performance audits, and simulator previews into a single plugin architecture that runs inside Codex. ## Plugin Manifest and Registration The top-level configuration lives in [`plugins/build-ios-apps/.codex-plugin/plugin.json`](https://github.com/openai/plugins/blob/main/plugins/build-ios-apps/.codex-plugin/plugin.json). ```json { "name": "build-ios-apps", "version": "0.1.1", "description": "Build iOS apps with workflows for App Intents, SwiftUI UI work, …", "skills": "./skills/", "interface": { "displayName": "Build iOS Apps", "capabilities": ["Interactive","Read","Write"] } } ``` This manifest registers the plugin with Codex, declares **Interactive**, **Read**, and **Write** capabilities, and points to the `skills/` directory. *(source: [[`plugins/build-ios-apps/.codex-plugin/plugin.json`](https://github.com/openai/plugins/blob/main/plugins/build-ios-apps/.codex-plugin/plugin.json)](https://github.com/openai/plugins/blob/main/plugins/build-ios-apps/.codex-plugin/plugin.json))* ## Skill Package Layout Each skill follows a conventional layout under `plugins/build-ios-apps/skills//`: - [`SKILL.md`](https://github.com/openai/plugins/blob/main/SKILL.md) — Human-readable workflow and quick-start. - `agents/` — Surface-specific agents such as [`openai.yaml`](https://github.com/openai/plugins/blob/main/openai.yaml). - `references/` — Markdown docs and Swift snippets. - `scripts/` — Optional helper scripts. - `assets/` — Optional icons and images. *(overview: [[`plugins/build-ios-apps/README.md`](https://github.com/openai/plugins/blob/main/plugins/build-ios-apps/README.md)](https://github.com/openai/plugins/blob/main/plugins/build-ios-apps/README.md))* ## Core SwiftUI Development Skills ### swiftui-ui-patterns The `swiftui-ui-patterns` skill is the central reference for **state ownership**, **navigation**, and **sheet handling**. Its [`SKILL.md`](https://github.com/openai/plugins/blob/main/SKILL.md) enforces rules such as preferring `@State` and `@Binding`, adopting `@Observable` on iOS 17+, and falling back to `ObservableObject` on earlier OSes. All component references are indexed in [[`skills/swiftui-ui-patterns/references/components-index.md`](https://github.com/openai/plugins/blob/main/skills/swiftui-ui-patterns/references/components-index.md)](https://github.com/openai/plugins/blob/main/plugins/build-ios-apps/skills/swiftui-ui-patterns/references/components-index.md), which links to concrete implementation snippets for `NavigationStack`, `TabView`, and sheets. ### swiftui-liquid-glass The `swiftui-liquid-glass` skill provides boilerplate for Apple’s **Liquid Glass APIs** (iOS 26+). It walks through adding the `LiquidGlass` dependency via Swift Package Manager and using the `GlassBackground` wrapper, which internally handles `#available(iOS 26, *)` checks. See [[`skills/swiftui-liquid-glass/SKILL.md`](https://github.com/openai/plugins/blob/main/skills/swiftui-liquid-glass/SKILL.md)](https://github.com/openai/plugins/blob/main/plugins/build-ios-apps/skills/swiftui-liquid-glass/SKILL.md) for the exact [`Package.swift`](https://github.com/openai/plugins/blob/main/Package.swift) snippet and Reference 22 for availability patterns. ### swiftui-performance-audit This skill combines three documents: - [`profiling-intake.md`](https://github.com/openai/plugins/blob/main/profiling-intake.md) — Describes how to attach Instruments and ETTrace. - [`report-template.md`](https://github.com/openai/plugins/blob/main/report-template.md) — Auto-populated after an audit run. - [`code-smells.md`](https://github.com/openai/plugins/blob/main/code-smells.md) — Checklist matched against view code during the audit. Together they generate a flame-graph and hotspot report via the `optimizing-swiftui-performance` helper script. ## Simulator and Debug Tooling ### ios-simulator-browser The `ios-simulator-browser` skill runs a **hot-reload preview server** through a small script called `swiftui-preview-browser.mjs`. It exposes compiled previews over a local web server so you can see live UI updates directly inside the Codex UI. Template entries live in [[`skills/ios-simulator-browser/scripts/templates/PreviewBrowserEntries.swift`](https://github.com/openai/plugins/blob/main/skills/ios-simulator-browser/scripts/templates/PreviewBrowserEntries.swift)](https://github.com/openai/plugins/blob/main/plugins/build-ios-apps/skills/ios-simulator-browser/scripts/templates/PreviewBrowserEntries.swift). ### MCP Wiring and Remote Debugging The plugin ships with a **Multi-Channel Protocol** config in [`.mcp.json`](https://github.com/openai/plugins/blob/main/.mcp.json) that connects the Codex runtime to **XcodeBuildMCP**. This enables **build**, **run**, and **debug** steps on a running simulator without leaving the Codex environment. *(source: [[`plugins/build-ios-apps/.mcp.json`](https://github.com/openai/plugins/blob/main/plugins/build-ios-apps/.mcp.json)](https://github.com/openai/plugins/blob/main/plugins/build-ios-apps/.mcp.json))* ## Practical Code Examples ### Adding a New SwiftUI Screen Using UI Patterns ```swift import SwiftUI // 1️⃣ Define the view-specific state – narrow as possible struct SettingsView: View { @State private var enableNotifications = false // local UI state } // 2️⃣ Use the recommended navigation pattern (NavigationStack) struct ContentView: View { var body: some View { NavigationStack { List { NavigationLink("Settings", destination: SettingsView()) } .navigationTitle("Demo App") } } } ``` This follows Rule 30 in `swiftui-ui-patterns`: isolate UI state with `@State` and adopt `NavigationStack` as documented in [`references/navigationstack.md`](https://github.com/openai/plugins/blob/main/references/navigationstack.md). ### Enabling Liquid Glass in a New View ```swift import SwiftUI import LiquidGlass // added via SwiftPM (see references/liquid-glass.md) struct GlassyProfileView: View { var body: some View { GlassBackground { VStack { Text("Profile") .font(.largeTitle) .foregroundColor(.white) // … other UI … } } // GlassBackground automatically respects iOS 26+ availability } } ``` ### Running a Performance Audit from the Skill ```bash # From the repository root (Codex will invoke the skill) codex run swiftui-performance-audit \ --target MyApp \ --device "iPhone 15 Pro" \ --profile "MainFlow" ``` The skill will: 1. Launch Instruments with an ETTrace template. 2. Capture a flame-graph and feed it to `optimizing-swiftui-performance`. 3. Generate [`report-template.md`](https://github.com/openai/plugins/blob/main/report-template.md) with hotspots and suggested refactors. *(Automation details are in [`skills/swiftui-performance-audit/references/optimizing-swiftui-performance.md`](https://github.com/openai/plugins/blob/main/skills/swiftui-performance-audit/references/optimizing-swiftui-performance.md))* ## How to Use the Plugin in Your Own Codex Extension 1. **Add the plugin as a dependency** — Clone the `openai/plugins` repository and reference the `plugins/build-ios-apps` folder in your `.codex-plugin` manifest. 2. **Invoke a skill** via the Codex API: ```json { "plugin": "build-ios-apps", "skill": "swiftui-ui-patterns", "intent": "Create a new TabView with NavigationStack", "params": { "projectName": "MyDemoApp" } } ``` 3. **Follow the skill’s quick-start** found in its [`SKILL.md`](https://github.com/openai/plugins/blob/main/SKILL.md). The skill will generate scaffolding files, update your Xcode project, and optionally launch the simulator browser for live preview. 4. **Iterate** using the `swiftui-view-refactor` skill to break large views, or the `swiftui-performance-audit` skill to optimize after each iteration. ## Summary - The **Build‑iOS‑Apps** plugin provides a complete SwiftUI development pipeline inside Codex through modular skills. - The manifest at [`.codex-plugin/plugin.json`](https://github.com/openai/plugins/blob/main/.codex-plugin/plugin.json) registers the plugin and points to the `skills/` directory. - **swiftui-ui-patterns** enforces modern state ownership and navigation conventions. - **swiftui-liquid-glass** offers iOS 26+ glassy UI boilerplate with availability guards. - **swiftui-performance-audit** automates profiling with ETTrace and generates a [`report-template.md`](https://github.com/openai/plugins/blob/main/report-template.md). - **ios-simulator-browser** delivers hot-reload previews via `swiftui-preview-browser.mjs`. - **MCP wiring** in [`.mcp.json`](https://github.com/openai/plugins/blob/main/.mcp.json) connects Codex to XcodeBuildMCP for simulator builds and debugging. ## Frequently Asked Questions ### What is the Build‑iOS‑Apps plugin and where is it located? The Build‑iOS‑Apps plugin is a Codex toolkit inside the `openai/plugins` repository. It lives under `plugins/build-ios-apps` and bundles skills for designing, building, and debugging SwiftUI iOS applications. ### How does the swiftui-ui-patterns skill handle state management? According to the source code in [[`skills/swiftui-ui-patterns/SKILL.md`](https://github.com/openai/plugins/blob/main/skills/swiftui-ui-patterns/SKILL.md)](https://github.com/openai/plugins/blob/main/plugins/build-ios-apps/skills/swiftui-ui-patterns/SKILL.md), the skill prefers `@State` and `@Binding` for local UI state, recommends `@Observable` on iOS 17 and later, and falls back to `ObservableObject` for earlier OS versions. ### Can I debug a simulator without leaving the Codex environment? Yes. The plugin ships an [`.mcp.json`](https://github.com/openai/plugins/blob/main/.mcp.json) configuration that wires Codex to XcodeBuildMCP, and the `ios-debugger-agent` skill handles debugging on a running simulator directly from the Codex interface. ### What iOS version is required for the Liquid Glass skill? The `swiftui-liquid-glass` skill targets **iOS 26 and later**. Its `GlassBackground` wrapper includes `#available(iOS 26, *)` checks so you can adopt the API safely while maintaining backward compatibility.