ultracite

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Translated

Ultracite is a zero-config linting and formatting preset for JavaScript/TypeScript projects. Use when: (1) Setting up or initializing Ultracite in a project (ultracite init), (2) Running linting or formatting commands (check, fix, doctor), (3) Writing or reviewing JS/TS code in a project that uses Ultracite — to follow its code standards, (4) Troubleshooting linting/formatting issues, (5) User mentions 'ultracite', 'lint', 'format', 'code quality', or 'biome/eslint/oxlint' in a project with Ultracite installed.

3installs

Sourcehaydenbleasel/ultracite

Added on2026-02-19

NPX Install

npx skill4agent add haydenbleasel/ultracite ultracite

SKILL.md Content

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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
```
.oxlintrc.json
```
→ Oxlint

CLI Commands

bash

# 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:

bash

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

Flags:

```
--pm
```
—
```
npm
```
|
```
yarn
```
|
```
pnpm
```
|
```
bun
```
```
--linter
```
—
```
biome
```
(recommended) |
```
eslint
```
|
```
oxlint
```

--editors

—

vscode

|

zed

|

cursor

|

windsurf

|

antigravity

|

kiro

|

trae

|

void

--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:

jsonc

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

Framework presets available per linter:

core

,

react

,

next

,

solid

,

vue

,

svelte

,

qwik

,

remix

,

angular

,

astro

,

nestjs

.

Code Standards

When writing code in a project with Ultracite, follow these standards. For the full rules reference, see references/code-standards.md.

Key rules at a glance:

Formatting: 2-space indent, semicolons, double quotes, 80-char width, ES5 trailing commas, LF line endings.

Style: Arrow functions preferred.

const

by default, never

var

.

for...of

over

.forEach()

. Template literals over concatenation. No enums (use objects with

as const

). No nested ternaries. Kebab-case filenames.

Correctness: No unused imports/variables. No

any

(use

unknown

). Always

await

promises in async functions. No

console.log

/

debugger

/

alert

in production.

React: Function components only. Hooks at top level. Exhaustive deps.

key

on iterables (no array index). No nested component definitions. Semantic HTML + ARIA.

Performance: No accumulating spread in loops. No barrel files. No namespace imports. Top-level regex.

Security:

rel="noopener"

on

target="_blank"

. No

dangerouslySetInnerHTML