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GEMINI.md

GEMINI.md for Swift

GEMINI.md is the project context file the Gemini CLI reads from the repository root. It should say how this codebase is built, tested, and reviewed so Gemini does not guess. This copy is written for a Swift project. This repository is a Swift app for Apple platforms. Match SwiftUI or UIKit, whichever the target already uses. Stay off the main actor only for work that is actually background work.

The example uses a balanced, readable style, pragmatic tests, and comments only where the intent is not obvious. Open the generator to make the agent stricter, switch to test-first, quiet the comments, or pick a different file.

The example assumes a Swift iOS or multiplatform app. It does not assume SwiftData, a particular architecture acronym, or a third-party UI kit. Follow the UI stack already on screen.

Example file

Balanced strictness, readable style, pragmatic tests. Download name: GEMINI.md

# GEMINI.md

Project context for the Gemini CLI in this Swift repository. Read it before editing.
Other agents can follow the same rules, but Gemini loads this filename automatically.

## Stack

This repository is a Swift app for Apple platforms. Match SwiftUI or UIKit, whichever the target already uses. Stay off the main actor only for work that is actually background work.

## Layout

- Features sit in the group or Swift package the project already uses.
- Views do not own networking. A type the project already has loads data.
- Preview providers stay next to the view they preview.

## Commands

- Tests: `xcodebuild test`
- Open: `Open the project in Xcode and build the app target`

Use the script the repo already defines when it differs from the command above.

## Conventions

- Do not force-unwrap input that can be missing. Use `if let` or `guard`.
- UI updates hop to the main actor.
- Prefer async/await over new callback pyramids when the file already uses concurrency.
- Keep `@State` local. Hoist state only when two views need it.
- Match the existing navigation API. Do not mix NavigationView and NavigationStack in new code.
- Name types the way the module already does.

## Testing

Add or update tests when behavior changes.

Add an XCTest for the type that owns the rule. Do not snapshot the whole screen as the only check.

## Style

- Optimize for the next reader over the shortest diff.
- Comment only when the why is non-obvious.
- Name things the way neighboring files already do.
- Do not reformat code you did not change.

## Errors

- Fail at the boundary. Do not swallow errors.
- Model recoverable failure as a thrown error or a Result the view can show. Do not `try!` on user input.

## Scope

- Do the requested task. Do not refactor unrelated code.
- Match the rigor already in the repo. Fix what you touch.
- Ask one clarifying question only when the task cannot be finished without it. Otherwise state the assumption and continue.

## Avoid

- Do not capture `self` strongly in a long-lived task without a reason.
- Do not block the main thread with file or network I/O.
- Do not add a new architecture layer for one screen.
- Do not disable a compiler warning to ship a force cast.

## Done when

- The requested behavior works.
- The app target builds and the XCTest for the type you changed passes.
- The diff stays inside the task.
- You list anything you could not run.

Add it to the project

  1. 01

    Copy a starting file

    Copy the example GEMINI.md on this page, or open the generator if you want different testing, strictness, or comment rules.

  2. 02

    Save it at GEMINI.md

    Save it as `GEMINI.md` at the root of the Swift repo. Start a new Gemini CLI session so it picks up the file.

  3. 03

    Start a fresh agent session

    Rules files are read when a session starts. A chat that is already open may still be using the old instructions.

  4. 04

    Give it one small task

    Ask for one change a Swift agent often gets wrong, such as a view model change that publishes on the main actor and has an XCTest. If it ignores the file, confirm the path and start a new session.

Questions about this file

Where do I put GEMINI.md in a Swift repo?

Save it as `GEMINI.md` at the root of the Swift repo. Start a new Gemini CLI session so it picks up the file.

Which tools read this GEMINI.md?

The Gemini CLI reads GEMINI.md as project context. Claude Code reads CLAUDE.md instead, and most other agents read AGENTS.md.

What does the Swift example assume?

The example assumes a Swift iOS or multiplatform app. It does not assume SwiftData, a particular architecture acronym, or a third-party UI kit. Follow the UI stack already on screen.

Does VibeSpell upload my repository?

No. Recipe pages are static, and the generator builds the file in your browser from the options you pick. Your source code never leaves the machine.

Other files for Swift

GEMINI.md for other stacks