Ultracite

What it does

When your agent uses it

• Initializing Ultracite in a project (ultracite init)
• Running linting
• Formatting commands (check
• Reviewing JS/TS code in a project that uses Ultracite — to follow its code standards

Example prompts

• “ultracite”
• “format”
• “code quality”
• “/ultracite”

Workflow steps

4 steps, taken from the first numbered list in SKILL.md.

1. 1Linter installation (biome/eslint/oxlint binary available)
2. 2Config validity (extends ultracite presets correctly)
3. 3Ultracite in package.json dependencies
4. 4Conflicting tools (old .eslintrc.*, .prettierrc.* files)

What it can do on your machine

Read from SKILL.md and the folder at commit 22ad8f3. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • bunx
  • yarn

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md. Its commands use bunx and yarn, which can reach the network depending on how they are called.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Ultracite loads about 1.2k tokens when it runs, and up to ~2.3k if it reads all its reference files. Until then it costs about 132 tokens; SKILL.md has 433 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~132

When it runs · the whole SKILL.md, loaded when a task matches

~1.2k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~2.3k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from agustinusnathaniel/nextarter-tailwind at commit 22ad8f3, republished under its MIT licence (© agustinusnathaniel). 433 words, ~1,195 tokens.

name

ultracite

description

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.

# 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

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

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

© agustinusnathaniel, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 1 other file (references) in .agents/skills/ultracite of agustinusnathaniel/nextarter-tailwind.

• SKILL.md
• references/code-standards.md

Open the folder on GitHubat commit 22ad8f3

Used in 2 other repositories

We found 2 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 2 other GitHub owners. This page covers the copy in agustinusnathaniel/nextarter-tailwind, which our catalogue first saw on October 7, 2026.

• lirena00/monochromate.agents/skills/ultracite
• c15t/c15t.agents/skills/ultracite