# Ultracite for Amazon Q CLI

Use Ultracite with Amazon Q CLI when you want terminal AI assistance that spans code and cloud-oriented workflows without losing repo discipline. It is especially useful in full-stack repositories where application code sits close to operational tooling.

## Setup details

These values come from the same data Ultracite uses when it creates or updates Amazon Q CLI instructions, so the page matches what actually gets written into the repo.

Run `npx ultracite@latest init --agents amazon-q-cli` and Ultracite will update the configuration file located at `.amazonq/rules/ultracite.md` for the default setup.

### Configuration file

Ultracite writes to this exact file when you initialize or update the agent integration.

### Write mode

Append to existing instructions. Existing instructions stay in place and Ultracite appends its rules where the agent expects them.

### Header handling

Writes rules directly. The generated file starts directly with Ultracite rules and skips an extra heading block.

### Hook support

No separate hook file. Amazon Q CLI does not use a separate hook configuration in Ultracite.

## Files Ultracite writes for Amazon Q CLI

This preview shows the exact default file content Ultracite writes for Amazon Q CLI when you use the standard Biome setup.

```markdown
# Ultracite Code Standards

This project uses **Ultracite**, a zero-config preset that enforces strict code quality standards through automated formatting and linting.

## Quick Reference
- **Format code**: `npx ultracite fix`
- **Check for issues**: `npx ultracite check`
- **Diagnose setup**: `npx ultracite doctor`

Biome (the underlying engine) provides robust linting and formatting. Most issues are automatically fixable.

---

## Core Principles

Write code that is **accessible, performant, type-safe, and maintainable**. Focus on clarity and explicit intent over brevity.

### Type Safety & Explicitness
- Use explicit types for function parameters and return values when they enhance clarity
- Prefer `unknown` over `any` when the type is genuinely unknown
- Use const assertions (`as const`) for immutable values and literal types
- Leverage TypeScript's type narrowing instead of type assertions
- Use meaningful variable names instead of magic numbers - extract constants with descriptive names

### Modern JavaScript/TypeScript
- Use arrow functions for callbacks and short functions
- Prefer `for...of` loops over `.forEach()` and indexed `for` loops
- Use optional chaining (`?.`) and nullish coalescing (`??`) for safer property access
- Prefer template literals over string concatenation
- Use destructuring for object and array assignments
- Use `const` by default, `let` only when reassignment is needed, never `var`

### Async & Promises
- Always `await` promises in async functions - don't forget to use the return value
- Use `async/await` syntax instead of promise chains for better readability
- Handle errors appropriately in async code with try-catch blocks
- Don't use async functions as Promise executors

### React & JSX
- Use function components over class components
- Call hooks at the top level only, never conditionally
- Specify all dependencies in hook dependency arrays correctly
- Use the `key` prop for elements in iterables (prefer unique IDs over array indices)
- Nest children between opening and closing tags instead of passing as props
- Don't define components inside other components
- Use semantic HTML and ARIA attributes for accessibility:
  - Provide meaningful alt text for images
  - Use proper heading hierarchy
  - Add labels for form inputs
  - Include keyboard event handlers alongside mouse events
  - Use semantic elements (`<button>`, `<nav>`, etc.) instead of divs with roles

### Error Handling & Debugging
- Remove `console.log`, `debugger`, and `alert` statements from production code
- Throw `Error` objects with descriptive messages, not strings or other values
- Use `try-catch` blocks meaningfully - don't catch errors just to rethrow them
- Prefer early returns over nested conditionals for error cases

### Code Organization
- Keep functions focused and under reasonable cognitive complexity limits
- Extract complex conditions into well-named boolean variables
- Use early returns to reduce nesting
- Prefer simple conditionals over nested ternary operators
- Group related code together and separate concerns

### Security
- Add `rel="noopener"` when using `target="_blank"` on links
- Avoid `dangerouslySetInnerHTML` unless absolutely necessary
- Don't use `eval()` or assign directly to `document.cookie`
- Validate and sanitize user input

### Performance
- Avoid spread syntax in accumulators within loops
- Use top-level regex literals instead of creating them in loops
- Prefer specific imports over namespace imports
- Avoid barrel files (index files that re-export everything)
- Use proper image components (e.g., Next.js `<Image>`) over `<img>` tags

### Framework-Specific Guidance

**Next.js:**
- Use Next.js `<Image>` component for images
- Use `next/head` or App Router metadata API for head elements
- Use Server Components for async data fetching instead of async Client Components

**React 19+:**
- Use ref as a prop instead of `React.forwardRef`

**Solid/Svelte/Vue/Qwik:**
- Use `class` and `for` attributes (not `className` or `htmlFor`)

---

## Testing

- Write assertions inside `it()` or `test()` blocks
- Avoid done callbacks in async tests - use async/await instead
- Don't use `.only` or `.skip` in committed code
- Keep test suites reasonably flat - avoid excessive `describe` nesting

## When Biome Can't Help

Biome's linter will catch most issues automatically. Focus your attention on:
1. **Business logic correctness** - Biome can't validate your algorithms
2. **Meaningful naming** - Use descriptive names for functions, variables, and types
3. **Architecture decisions** - Component structure, data flow, and API design
4. **Edge cases** - Handle boundary conditions and error states
5. **User experience** - Accessibility, performance, and usability considerations
6. **Documentation** - Add comments for complex logic, but prefer self-documenting code

---

Most formatting and common issues are automatically fixed by Biome. Run `npx ultracite fix` before committing to ensure compliance.
```

## Best for

These are the workflows where Ultracite adds the most leverage to Amazon Q CLI, based on how the agent reads instructions and how teams typically wire it into day-to-day development.

01. **Full-stack application repos** - Keep Amazon Q CLI aligned when it edits frontend, backend, and support scripts in one repository.
02. **Cloud-adjacent code changes** - Use committed repo rules when the same workflow touches infrastructure scripts and application logic.
03. **Terminal-first AWS teams** - Store guidance in Amazon Q's rules directory so every contributor gets the same coding contract.

## Why this setup works for Amazon Q CLI

These differentiators come from the way Amazon Q CLI actually handles repo instructions, file updates, and AI-assisted development work.

### AWS-aware terminal workflow

Amazon Q CLI often sits close to infrastructure and deployment tasks, so repo standards help code changes stay disciplined in a broader operational workflow.

### Dedicated rules location

Ultracite uses Amazon Q's rules directory so project guidance stays clearly scoped to the tool.

### Strong fit for full-stack repos

This setup helps when Amazon Q CLI touches application code, scripts, and cloud-adjacent files in the same repository.

## Install in seconds. Run in milliseconds.

Install Ultracite and start shipping code faster in seconds.
