SwiftUI rules for AI coding agents
Full stack: Swift + SwiftUI
Ready-to-commit rules for Swift + SwiftUI in every major format: AGENTS.md (Codex, Cursor, Copilot), CLAUDE.md (Claude Code), Cursor .mdc project rules, legacy .cursorrules, Copilot instructions, Windsurf rules and GEMINI.md. A native iOS app with SwiftUI and Swift concurrency.
Last reviewed 2026-10-21 · Customise in the generator · Raw: AGENTS.md, CLAUDE.md
The mistake agents make most on this stack
Agents use pre-iOS 17 `ObservableObject` patterns and force-unwrap optionals.
Generated files
AGENTS.md
# AGENTS.md - this project
Instructions for AI coding agents working in this repository.
## Project
A Swift + SwiftUI project.
Stack: Swift + SwiftUI.
## Commands
- Build: `xcodebuild -scheme <Scheme> build`
- Tests: `xcodebuild test -scheme <Scheme> -destination "platform=iOS Simulator,name=iPhone 16"`
## How to work in this repo
- Read the relevant files before editing. Follow the patterns already in the codebase over these generic rules.
- Make the smallest change that solves the task. Do not refactor or reformat unrelated code.
- Before saying a task is done, run the type-check, lint and tests listed under Commands and fix what you broke.
- If requirements are ambiguous, ask one clear question instead of guessing.
- Never commit secrets, API keys or `.env` files. Use env vars and keep `.env.example` up to date.
- Do not add a new dependency when the standard library or an existing dependency already covers it.
- Ask before adding, removing or upgrading any dependency.
- Ask before changing database schemas, auth, payments or CI configuration.
- Never delete files, drop data or run destructive commands (`rm -rf`, `git push --force`, `DROP TABLE`) without explicit approval.
- Keep each change under ~200 changed lines where possible; split larger work into steps.
## Swift + SwiftUI
- Use SwiftUI for new UI. Keep views small; extract subviews instead of long `body` properties.
- For iOS 17+ targets, use the Observation framework (`@Observable`) instead of `ObservableObject` / `@Published`.
- Use async/await and structured concurrency. Mark UI-facing types `@MainActor`.
- Respect Swift 6 strict concurrency: make shared types `Sendable` instead of silencing warnings.
- No force unwraps (`!`) outside tests.
- Store secrets in the Keychain, never in `UserDefaults`.
- Avoid editing `.pbxproj` by hand; ask the user to add files or targets in Xcode if needed.
## Reference docs
- [SwiftUI docs](https://developer.apple.com/documentation/swiftui)
CLAUDE.md
# CLAUDE.md - this project
Project instructions for Claude Code.
## Project
A Swift + SwiftUI project.
Stack: Swift + SwiftUI.
## Commands
- Build: `xcodebuild -scheme <Scheme> build`
- Tests: `xcodebuild test -scheme <Scheme> -destination "platform=iOS Simulator,name=iPhone 16"`
## How to work in this repo
- Read the relevant files before editing. Follow the patterns already in the codebase over these generic rules.
- Make the smallest change that solves the task. Do not refactor or reformat unrelated code.
- Before saying a task is done, run the type-check, lint and tests listed under Commands and fix what you broke.
- If requirements are ambiguous, ask one clear question instead of guessing.
- Never commit secrets, API keys or `.env` files. Use env vars and keep `.env.example` up to date.
- Do not add a new dependency when the standard library or an existing dependency already covers it.
- Ask before adding, removing or upgrading any dependency.
- Ask before changing database schemas, auth, payments or CI configuration.
- Never delete files, drop data or run destructive commands (`rm -rf`, `git push --force`, `DROP TABLE`) without explicit approval.
- Keep each change under ~200 changed lines where possible; split larger work into steps.
## Swift + SwiftUI
- Use SwiftUI for new UI. Keep views small; extract subviews instead of long `body` properties.
- For iOS 17+ targets, use the Observation framework (`@Observable`) instead of `ObservableObject` / `@Published`.
- Use async/await and structured concurrency. Mark UI-facing types `@MainActor`.
- Respect Swift 6 strict concurrency: make shared types `Sendable` instead of silencing warnings.
- No force unwraps (`!`) outside tests.
- Store secrets in the Keychain, never in `UserDefaults`.
- Avoid editing `.pbxproj` by hand; ask the user to add files or targets in Xcode if needed.
## Reference docs
- [SwiftUI docs](https://developer.apple.com/documentation/swiftui)
.cursor/rules/project.mdc
---
description: "Core rules for this project"
alwaysApply: true
---
# this project
A Swift + SwiftUI project.
Stack: Swift + SwiftUI.
## Commands
- Build: `xcodebuild -scheme <Scheme> build`
- Tests: `xcodebuild test -scheme <Scheme> -destination "platform=iOS Simulator,name=iPhone 16"`
## How to work in this repo
- Read the relevant files before editing. Follow the patterns already in the codebase over these generic rules.
- Make the smallest change that solves the task. Do not refactor or reformat unrelated code.
- Before saying a task is done, run the type-check, lint and tests listed under Commands and fix what you broke.
- If requirements are ambiguous, ask one clear question instead of guessing.
- Never commit secrets, API keys or `.env` files. Use env vars and keep `.env.example` up to date.
- Do not add a new dependency when the standard library or an existing dependency already covers it.
- Ask before adding, removing or upgrading any dependency.
- Ask before changing database schemas, auth, payments or CI configuration.
- Never delete files, drop data or run destructive commands (`rm -rf`, `git push --force`, `DROP TABLE`) without explicit approval.
- Keep each change under ~200 changed lines where possible; split larger work into steps.
.cursor/rules/swiftui.mdc
---
description: "Swift + SwiftUI conventions: iOS/macOS app with SwiftUI and Swift concurrency."
globs: **/*.swift
alwaysApply: false
---
# Swift + SwiftUI
- Use SwiftUI for new UI. Keep views small; extract subviews instead of long `body` properties.
- For iOS 17+ targets, use the Observation framework (`@Observable`) instead of `ObservableObject` / `@Published`.
- Use async/await and structured concurrency. Mark UI-facing types `@MainActor`.
- Respect Swift 6 strict concurrency: make shared types `Sendable` instead of silencing warnings.
- No force unwraps (`!`) outside tests.
- Store secrets in the Keychain, never in `UserDefaults`.
- Avoid editing `.pbxproj` by hand; ask the user to add files or targets in Xcode if needed.
Docs: https://developer.apple.com/documentation/swiftui
.cursorrules
# Cursor rules - this project
You are an expert Swift + SwiftUI engineer working on this codebase. Follow these rules.
## Project
A Swift + SwiftUI project.
Stack: Swift + SwiftUI.
## Commands
- Build: `xcodebuild -scheme <Scheme> build`
- Tests: `xcodebuild test -scheme <Scheme> -destination "platform=iOS Simulator,name=iPhone 16"`
## How to work in this repo
- Read the relevant files before editing. Follow the patterns already in the codebase over these generic rules.
- Make the smallest change that solves the task. Do not refactor or reformat unrelated code.
- Before saying a task is done, run the type-check, lint and tests listed under Commands and fix what you broke.
- If requirements are ambiguous, ask one clear question instead of guessing.
- Never commit secrets, API keys or `.env` files. Use env vars and keep `.env.example` up to date.
- Do not add a new dependency when the standard library or an existing dependency already covers it.
- Ask before adding, removing or upgrading any dependency.
- Ask before changing database schemas, auth, payments or CI configuration.
- Never delete files, drop data or run destructive commands (`rm -rf`, `git push --force`, `DROP TABLE`) without explicit approval.
- Keep each change under ~200 changed lines where possible; split larger work into steps.
## Swift + SwiftUI
- Use SwiftUI for new UI. Keep views small; extract subviews instead of long `body` properties.
- For iOS 17+ targets, use the Observation framework (`@Observable`) instead of `ObservableObject` / `@Published`.
- Use async/await and structured concurrency. Mark UI-facing types `@MainActor`.
- Respect Swift 6 strict concurrency: make shared types `Sendable` instead of silencing warnings.
- No force unwraps (`!`) outside tests.
- Store secrets in the Keychain, never in `UserDefaults`.
- Avoid editing `.pbxproj` by hand; ask the user to add files or targets in Xcode if needed.
## Reference docs
- [SwiftUI docs](https://developer.apple.com/documentation/swiftui)
.github/copilot-instructions.md
# Copilot instructions - this project
A Swift + SwiftUI project.
Stack: Swift + SwiftUI.
## Commands
- Build: `xcodebuild -scheme <Scheme> build`
- Tests: `xcodebuild test -scheme <Scheme> -destination "platform=iOS Simulator,name=iPhone 16"`
## How to work in this repo
- Read the relevant files before editing. Follow the patterns already in the codebase over these generic rules.
- Make the smallest change that solves the task. Do not refactor or reformat unrelated code.
- Before saying a task is done, run the type-check, lint and tests listed under Commands and fix what you broke.
- If requirements are ambiguous, ask one clear question instead of guessing.
- Never commit secrets, API keys or `.env` files. Use env vars and keep `.env.example` up to date.
- Do not add a new dependency when the standard library or an existing dependency already covers it.
- Ask before adding, removing or upgrading any dependency.
- Ask before changing database schemas, auth, payments or CI configuration.
- Never delete files, drop data or run destructive commands (`rm -rf`, `git push --force`, `DROP TABLE`) without explicit approval.
- Keep each change under ~200 changed lines where possible; split larger work into steps.
.github/instructions/swiftui.instructions.md
---
applyTo: "**/*.swift"
---
# Swift + SwiftUI
- Use SwiftUI for new UI. Keep views small; extract subviews instead of long `body` properties.
- For iOS 17+ targets, use the Observation framework (`@Observable`) instead of `ObservableObject` / `@Published`.
- Use async/await and structured concurrency. Mark UI-facing types `@MainActor`.
- Respect Swift 6 strict concurrency: make shared types `Sendable` instead of silencing warnings.
- No force unwraps (`!`) outside tests.
- Store secrets in the Keychain, never in `UserDefaults`.
- Avoid editing `.pbxproj` by hand; ask the user to add files or targets in Xcode if needed.
.windsurf/rules/project.md
---
trigger: always_on
---
# this project
A Swift + SwiftUI project.
Stack: Swift + SwiftUI.
## Commands
- Build: `xcodebuild -scheme <Scheme> build`
- Tests: `xcodebuild test -scheme <Scheme> -destination "platform=iOS Simulator,name=iPhone 16"`
## How to work in this repo
- Read the relevant files before editing. Follow the patterns already in the codebase over these generic rules.
- Make the smallest change that solves the task. Do not refactor or reformat unrelated code.
- Before saying a task is done, run the type-check, lint and tests listed under Commands and fix what you broke.
- If requirements are ambiguous, ask one clear question instead of guessing.
- Never commit secrets, API keys or `.env` files. Use env vars and keep `.env.example` up to date.
- Do not add a new dependency when the standard library or an existing dependency already covers it.
- Ask before adding, removing or upgrading any dependency.
- Ask before changing database schemas, auth, payments or CI configuration.
- Never delete files, drop data or run destructive commands (`rm -rf`, `git push --force`, `DROP TABLE`) without explicit approval.
- Keep each change under ~200 changed lines where possible; split larger work into steps.
.windsurf/rules/swiftui.md
---
trigger: glob
globs: **/*.swift
---
# Swift + SwiftUI
- Use SwiftUI for new UI. Keep views small; extract subviews instead of long `body` properties.
- For iOS 17+ targets, use the Observation framework (`@Observable`) instead of `ObservableObject` / `@Published`.
- Use async/await and structured concurrency. Mark UI-facing types `@MainActor`.
- Respect Swift 6 strict concurrency: make shared types `Sendable` instead of silencing warnings.
- No force unwraps (`!`) outside tests.
- Store secrets in the Keychain, never in `UserDefaults`.
- Avoid editing `.pbxproj` by hand; ask the user to add files or targets in Xcode if needed.
GEMINI.md
# GEMINI.md - this project
Project context for Gemini CLI.
## Project
A Swift + SwiftUI project.
Stack: Swift + SwiftUI.
## Commands
- Build: `xcodebuild -scheme <Scheme> build`
- Tests: `xcodebuild test -scheme <Scheme> -destination "platform=iOS Simulator,name=iPhone 16"`
## How to work in this repo
- Read the relevant files before editing. Follow the patterns already in the codebase over these generic rules.
- Make the smallest change that solves the task. Do not refactor or reformat unrelated code.
- Before saying a task is done, run the type-check, lint and tests listed under Commands and fix what you broke.
- If requirements are ambiguous, ask one clear question instead of guessing.
- Never commit secrets, API keys or `.env` files. Use env vars and keep `.env.example` up to date.
- Do not add a new dependency when the standard library or an existing dependency already covers it.
- Ask before adding, removing or upgrading any dependency.
- Ask before changing database schemas, auth, payments or CI configuration.
- Never delete files, drop data or run destructive commands (`rm -rf`, `git push --force`, `DROP TABLE`) without explicit approval.
- Keep each change under ~200 changed lines where possible; split larger work into steps.
## Swift + SwiftUI
- Use SwiftUI for new UI. Keep views small; extract subviews instead of long `body` properties.
- For iOS 17+ targets, use the Observation framework (`@Observable`) instead of `ObservableObject` / `@Published`.
- Use async/await and structured concurrency. Mark UI-facing types `@MainActor`.
- Respect Swift 6 strict concurrency: make shared types `Sendable` instead of silencing warnings.
- No force unwraps (`!`) outside tests.
- Store secrets in the Keychain, never in `UserDefaults`.
- Avoid editing `.pbxproj` by hand; ask the user to add files or targets in Xcode if needed.
## Reference docs
- [SwiftUI docs](https://developer.apple.com/documentation/swiftui)
Commands your agent should run
| Task | Command |
|---|---|
| Build | xcodebuild -scheme <Scheme> build |
| Tests | xcodebuild test -scheme <Scheme> -destination "platform=iOS Simulator,name=iPhone 16" |
What the rules cover
Swift + SwiftUI
iOS/macOS app with SwiftUI and Swift concurrency. Scoped to **/*.swift in Cursor, Copilot and Windsurf.
- Use SwiftUI for new UI. Keep views small; extract subviews instead of long
bodyproperties. - For iOS 17+ targets, use the Observation framework (
@Observable) instead ofObservableObject/@Published. - Use async/await and structured concurrency. Mark UI-facing types
@MainActor. - Respect Swift 6 strict concurrency: make shared types
Sendableinstead of silencing warnings. - No force unwraps (
!) outside tests. - Store secrets in the Keychain, never in
UserDefaults. - Avoid editing
.pbxprojby hand; ask the user to add files or targets in Xcode if needed.
Source docs: SwiftUI docs
How to install
- Copy
AGENTS.mdto your repo root. That covers Codex, Cursor, GitHub Copilot and most other agents. - Using Claude Code? Add a
CLAUDE.mdwith the single line@AGENTS.md, or use the standalone CLAUDE.md tab above. - Want rules that only load for certain files in Cursor? Add the
.cursor/rules/*.mdcfiles. - Commit the files so your whole team (and every agent) shares them.
FAQ
Where do I put the AGENTS.md for Swift + SwiftUI?
Save it as AGENTS.md in the root of your repository, next to your main config file. Codex, Cursor and GitHub Copilot pick it up automatically. For Claude Code, add a CLAUDE.md containing @AGENTS.md (or use the standalone CLAUDE.md on this page).
What is the most common mistake AI agents make with Swift + SwiftUI?
Agents use pre-iOS 17 ObservableObject patterns and force-unwrap optionals.
Which commands should the agent run to check its work?
For this stack: xcodebuild -scheme <Scheme> build, xcodebuild test -scheme <Scheme> -destination "platform=iOS Simulator,name=iPhone 16". They are listed in the generated files so the agent runs them before finishing a task.
Do these Swift + SwiftUI rules work with Cursor and Claude Code?
Yes. This page includes the same rules as AGENTS.md, CLAUDE.md, Cursor .mdc project rules, a legacy .cursorrules file, GitHub Copilot instructions, Windsurf rules and GEMINI.md.
Can I customise these rules?
Yes. Open this stack in the generator to add or remove libraries, set your project name and package manager, switch beginner explanations on, and download everything as a zip.
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