ultracite

Ultracite

Zero-config linting and formatting for JS/TS projects. Supports three linter backends: Biome (recommended), ESLint + Prettier, and Oxlint + Oxfmt.

Detecting Ultracite

Check if ultracite is in package.json devDependencies. Detect the active linter by looking for:

• biome.jsonc → Biome
• eslint.config.mjs → ESLint
• oxlint.config.ts → Oxlint

CLI Commands

# Check for issues (read-only)
bunx ultracite check

# Auto-fix issues
bunx ultracite fix

# Diagnose setup problems
bunx ultracite doctor

# Initialize in a new project
bunx ultracite init

Replace bunx with npx, pnpx, or yarn dlx depending on the package manager.

check and fix accept optional file paths: bunx ultracite check src/index.ts.

Initialization

bunx ultracite init runs an interactive setup. For non-interactive (CI) use, pass flags:

bunx ultracite init \
  --pm bun \
  --linter biome \
  --editors universal \
  --agents claude copilot \
  --frameworks react next \
  --integrations husky lint-staged \
  --quiet

Flags:

• --pm — npm | yarn | pnpm | bun
• --linter — biome (recommended) | eslint | oxlint
• --editors — universal (writes .vscode/settings.json for every VS Code-based editor) | vscode | zed | cursor | windsurf | antigravity | kiro | trae | void | bob | codebuddy
• --agents — claude | codex | copilot | cline | amp | gemini | cursor-cli + 19 more
• --frameworks — react | next | solid | vue | svelte | qwik | remix | angular | astro | nestjs
• --integrations — husky | lefthook | lint-staged | pre-commit
• --hooks — Enable auto-fix hooks for supported agents/editors
• --type-aware — Enable type-aware linting (oxlint only)
• --skip-install — Skip dependency installation
• --quiet — Suppress prompts (auto-detected when CI=true)

Init creates config that extends Ultracite presets:

// biome.jsonc
{ "extends": ["ultracite/biome/core", "ultracite/biome/react"] }