Use Ultracite with Lovable when you want fast app generation without dropping the quality bar your team expects from maintained code. It is especially helpful when a quick prototype is likely to turn into a shipped product with ongoing review and iteration.
These values come from the same data Ultracite uses when it creates or updates Lovable instructions, so the page matches what actually gets written into the repo.
AGENTS.md
Run npx ultracite@latest init --agents lovable and Ultracite will update this file for the default setup.
Ultracite writes to this exact file when you initialize or update the agent integration.
Existing instructions stay in place and Ultracite appends its rules where the agent expects them.
The generated file starts directly with Ultracite rules and skips an extra heading block.
Lovable does not use a separate hook configuration in Ultracite.
This preview shows the exact default file content Ultracite writes for Lovable when you use the standard Biome setup.
If Lovable supports hooks, the second tab shows the companion hook config that runs after AI-driven edits.
# Ultracite Code StandardsThis 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 PrinciplesWrite 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 HelpBiome's linter will catch most issues automatically. Focus your attention on:1. **Business logic correctness** - Biome can't validate your algorithms2. **Meaningful naming** - Use descriptive names for functions, variables, and types3. **Architecture decisions** - Component structure, data flow, and API design4. **Edge cases** - Handle boundary conditions and error states5. **User experience** - Accessibility, performance, and usability considerations6. **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.These are the workflows where Ultracite adds the most leverage to Lovable, based on how the agent reads instructions and how teams typically wire it into day-to-day development.
Keep Lovable aligned when a generated app moves beyond a demo and into a codebase your team will keep shipping.
Make architecture, typing, and framework conventions explicit before Lovable generates new pages, flows, or backend logic.
Use one committed AGENTS.md file so follow-up sessions and teammates inherit the same coding expectations.
These differentiators come from the way Lovable actually handles repo instructions, file updates, and AI-assisted development work.
Lovable can move from prompt to working app quickly, so explicit repo rules help generated code stay maintainable once the prototype becomes a real product.
Using `AGENTS.md` gives Lovable a committed project contract that can live alongside other agent tools instead of hiding standards in workspace-only settings.
Ultracite helps Lovable output feel closer to team-owned production code, which makes the handoff from idea to review much smoother.
If Codex, Jules, Replit Agent are close to the way you work, these neighboring integrations are worth comparing too.
Add Ultracite to Codex via AGENTS.md so OpenAI's coding agent produces repo-aware code that matches your team's linting and architecture standards.
Configure Jules with Ultracite through AGENTS.md so Google's async coding agent returns code that matches your repo standards and review expectations.
Configure Replit Agent with Ultracite through replit.md so browser-based app generation follows your repo's linting, architecture, and framework standards.
And used by thousands of open source projects.
Here's what some of the most innovative and forward-thinking developers in the React ecosystem have to say about Ultracite.