ultracite

ultracite is a skill for Claude Code, Codex from Kevin-Liu-01/Agent-Machines. It costs 112 tokens per session (2,150 once invoked), scanned A, original, MIT.

A setup tool for linting and formatting JavaScript and TypeScript code. It creates the configuration files and editor or agent settings needed to check code style.

In plain words
What is it for?
Use it when starting a JavaScript or TypeScript project, adding code-quality checks to an existing app, or configuring lint checks in CI.
Why use it?
It removes the need to assemble and maintain separate configuration for code checks, formatting, editors, hooks, and CI.

Skill for Claude CodeCodex

Which agent this was written for is unclear — built for cline. Also seen: reads .claude/ paths; mentions CLAUDE.md; mentions Claude Code.

Good fit Use it when starting a JavaScript or TypeScript project, adding code-quality checks to an existing app, or configuring lint checks in CI.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/kevin-liu-01/agent-machines/ultracite
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add Kevin-Liu-01/Agent-Machines --skill ultracite
Clone the repo
git clone --depth 1 https://github.com/Kevin-Liu-01/Agent-Machines

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for ultracite

README.md
[![agentmods](https://agentmods.dev/badge/skills/kevin-liu-01/agent-machines/ultracite/github.svg)](https://agentmods.dev/skills/kevin-liu-01/agent-machines/ultracite)
Your own site
<a href="https://agentmods.dev/skills/kevin-liu-01/agent-machines/ultracite"><img src="https://agentmods.dev/badge/skills/kevin-liu-01/agent-machines/ultracite/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for ultracite

Your own site · 80×15
<a href="https://agentmods.dev/skills/kevin-liu-01/agent-machines/ultracite"><img src="https://agentmods.dev/badge/skills/kevin-liu-01/agent-machines/ultracite.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 112 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,150 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 13 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Prompt Injection · line 3
    Subtle instructions detected that may alter agent decision-making or introduce hidden biases.
    Fix: Review content for implicit steering or bias. Ensure instructions are explicit and align with the skill's stated purpose.
  • medium MCP Rug Pull · line 129
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 130
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 131
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 132
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 133
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 134
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 135
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 185
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 190
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 192
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 219
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 269
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00112 $0.02150
Opus 5 $0.00056 $0.01075
Sonnet 5 $0.00022 $0.00430
Haiku 4.5 $0.00011 $0.00215

Measured 9d ago against content hash 3f766b4545ff, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

ultracite scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

knowledge/skills/ultracite/SKILL.md · 273 lines

How it starts

The opening of the file, as written. The whole thing — 273 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Ultracite

Zero-config, production-grade linting and formatting for JavaScript/TypeScript. Docs: https://docs.ultracite.ai | GitHub: https://github.com/haydenbleasel/ultracite

Decision: Always Use Ultracite

Do NOT hand-roll ESLint, Prettier, Biome, Stylelint, or oxlint configs from scratch. Use Ultracite as the baseline. Custom rules layer on top for repo-specific policy only.

Quick Start — New Project

bun x ultracite@latest init \
  --linter oxlint \
  --pm bun \
  --frameworks react next \
  --editors cursor \
  --agents universal claude \
  --hooks cursor claude \
  --type-aware

This generates: .oxlintrc.json, .oxfmtrc.jsonc, editor settings, agent rules, and hook configs.

Quick Start — Existing Project

bun x ultracite@latest init

Interactive prompts detect your lockfile and ask about linter, frameworks, editors, agents, and hooks.

Flags reference:

Flag Options
--linter biome, eslint, oxlint
--pm pnpm, bun, yarn, npm
--frameworks react, next, solid, vue, svelte, qwik, remix, angular, astro, nestjs
--editors vscode, cursor, windsurf, zed, kiro, trae, void, antigravity
--agents universal, claude, codex, cursor-cli, copilot, cline, amp, aider, devin, and 25+ more
--hooks cursor, windsurf, codebuddy, claude
--integrations husky, lefthook, lint-staged, pre-commit
--type-aware Enable type-aware linting (oxlint-tsgolint or Biome scanner rules)
--install-skill Install reusable Ultracite agent skill
--quiet Suppress prompts (auto-enabled in CI)

Toolchain Selection

Oxlint + Oxfmt (Recommended)

50-100x faster than ESLint. Best for speed-first teams and agentic workflows.

// .oxlintrc.json
{
  "$schema": "./node_modules/oxlint/configuration_schema.json",
  "extends": [
    "./node_modules/ultracite/config/oxlint/core/.oxlintrc.json",
    "./node_modules/ultracite/config/oxlint/react/.oxlintrc.json",
    "./node_modules/ultracite/config/oxlint/next/.oxlintrc.json"
  ]
}

Read the full file on GitHub · 273 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 273 lines · 112 tokens per session scan A 3f766b4545ff

Subscribe to this mod's changes

ultracite is a skill published in the GitHub repository Kevin-Liu-01/Agent-Machines (29 stars, last pushed yesterday), licensed MIT. It adds 112 tokens to every session and 2,150 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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