Development & Testing

Biome All-in-One Linter

Fast, all-in-one linter and formatter for JavaScript and TypeScript written in Rust, replacing ESLint and Prettier.

Claude Code Codex Copilot Cursor Gemini CLI Windsurf

Overview

Biome is a blazing-fast toolchain for JavaScript, TypeScript, JSX, and JSON that combines linting and formatting into a single tool written in Rust. It is designed as a drop-in replacement for ESLint and Prettier, offering 10-100x faster performance while maintaining compatibility with most common rules and formatting conventions.

AI agents can configure Biome with a single biome.json file that handles both linting rules and formatting preferences. This simplicity means fewer configuration files, no plugin compatibility issues, and faster CI runs. Your agent can run biome check to lint and format in one command, or use biome ci for strict CI-mode checking.

Biome supports over 200 lint rules including many from ESLint, typescript-eslint, and eslint-plugin-react. It provides actionable diagnostics with fix suggestions, import sorting, and consistent formatting. For teams tired of managing the ESLint + Prettier + plugin dependency tree, Biome offers a refreshingly simple alternative that AI agents can configure in seconds.

Who Is This For?

Teams replacing ESLint + Prettier with a single, faster tool
CI/CD pipelines that need fast linting without Node.js overhead
New projects starting with a simple, zero-config linting setup
Developers who want import sorting integrated with their linter

Installation

Setup for Claude Code

npm install -D @biomejs/biome
npx biome init
Claude Code runs: npx biome check --write .

Configuration

// biome.json
{
  "formatter": {
    "indentStyle": "space",
    "indentWidth": 2,
    "lineWidth": 100
  },
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true,
      "complexity": { "noForEach": "warn" },
      "suspicious": { "noExplicitAny": "error" }
    }
  },
  "organizeImports": { "enabled": true }
}