Ultracite is a highly opinionated, zero-configuration preset for JavaScript and TypeScript linting and formatting, positioned as "the linter and formatter for agentic development". Running npx ultracite init walks through choosing a toolchain, frameworks, editors and AI agents, then installs and configures everything. It supports three toolchains: Oxlint + Oxfmt (recommended), Biome, and ESLint + Prettier + Stylelint, and also publishes ready-made presets you can extend by hand.
The CLI adds ultracite check, fix, doctor and upgrade. ultracite fix --claude or --codex hands remaining unfixable issues to the Claude Code or Codex CLI, which repairs them file by file and re-lints each fix. Optional extras include type-aware linting and Oxlint JS plugins such as @shadcn/lint and anti-slop, and Ultracite can install git hooks, editor settings, a reusable agent skill and agent hooks.
Version 8 (8.0.0 released on October 11, 2026, 8.0.1 on October 14) makes every agent read Ultracite's rules from a single AGENTS.md, adding only the extra step four agents need: an @AGENTS.md import for Claude Code when a CLAUDE.md exists, a settings entry for Gemini CLI, an .aider.conf.yml that also runs ultracite fix on every file Aider edits, and a replit.md copy for Replit Agent. Ultracite was featured on Product Hunt on October 17, 2026.
Ultracite is free and MIT-licensed. Alongside the docs, the project publishes open research on the lint rules it enables and what coding agents do when one fires.
