biome

biome is a skill for Claude Code from ai-ecoverse/slicc. It costs 52 tokens per session (589 once invoked), scanned A, original, Apache-2.0.

A guide to using Biome through a shell command for checking, linting, and formatting JavaScript and related source files. Biome is a code-quality tool that can report or apply formatting changes.

In plain words
What is it for?
Use it to lint files, check formatting, format files or standard input, choose a configuration file, and interpret plain-text or JSON reports.
Why use it?
It explains the required packages, available commands, configuration lookup, and options so checks work in the project's virtual environment.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Use it to lint files, check formatting, format files or standard input, choose a configuration file, and interpret plain-text or JSON reports.

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Install with agentmods
npx agentmods add skills/ai-ecoverse/slicc/biome
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 ai-ecoverse/slicc --skill biome
Clone the repo
git clone --depth 1 https://github.com/ai-ecoverse/slicc

Made for: Claude Code.

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 biome

README.md
[![agentmods](https://agentmods.dev/badge/skills/ai-ecoverse/slicc/biome.svg)](https://agentmods.dev/skills/ai-ecoverse/slicc/biome)
Your own site
<a href="https://agentmods.dev/skills/ai-ecoverse/slicc/biome"><img src="https://agentmods.dev/badge/skills/ai-ecoverse/slicc/biome.svg" alt="Measured on agentmods" height="20"></a>
Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 589 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: 1 finding, 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 49
    Large whitespace padding was detected (a block of blank lines or a long run of spaces). This can push injected instructions below or to the right of the visible area so a human reviewer never sees them while the agent still reads them. Manual review of the hidden content is recommended.
    Fix: Remove the large whitespace padding (blank-line blocks or long space runs) and review any content hidden below or to the right of it. Keep skill files compact and reviewable so no instructions can be
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 $0.00052 $0.00589
Opus 5 $0.00026 $0.00295
Sonnet 5 $0.00010 $0.00118
Haiku 4.5 $0.00005 $0.00059

Measured 3d ago against content hash e43427c48665, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

biome 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 3d 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.

packages/vfs-root/workspace/skills/biome/SKILL.md · 56 lines

How it starts

The opening of the file, as written. The whole thing — 56 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Biome

Use the biome shell command for Biome checks inside the VFS. It is a thin wrapper over ipk-installed WASM packages, not a bundled Biome binary.

Install prerequisites

Install all three backing packages before linting or formatting:

ipk add -g @biomejs/wasm-web @biomejs/js-api esbuild-wasm

There is no CDN fallback. If a package is missing, follow the pinned ipk add command printed by biome --help or the error message.

Commands

Command Behavior
biome check <files...> Lint and check formatting. Add --write to apply formatting.
biome lint <files...> Lint only; never writes files.
biome format <file> Print formatted source. Add --write to update files.
biome format --check <files...> Report unformatted files without printing or writing changes.

format --write and format --check are mutually exclusive. For piped input, pass --stdin-file-path <path> so Biome selects the correct parser.

Configuration

Use --config-path <file> to select a config explicitly. Otherwise, discovery starts at the first target file's directory, or the current directory for stdin, and walks toward /. At each directory, biome.json takes precedence over biome.jsonc.

The wrapper accepts comments and trailing commas. It does not resolve extends.

Reporters

The default plain reporter emits diagnostics as plain text without HTML entities, HTML tags, or added ANSI escapes.

Use --reporter json or --json for one JSON document on stdout with summary, diagnostics, and files fields. JSON diagnostic text is not written to stderr, and selecting JSON does not change the exit code.

Exit codes

Code Meaning
0 No findings, and checked files are formatted.
1 Error, fatal, or warning diagnostics; unformatted checked files; missing packages/files; or invalid discovered config.
2 Usage error, including a missing or invalid explicit --config-path.

Read the full file on GitHub · 56 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. 3d ago First seen · 56 lines · 52 tokens per session scan A e43427c48665

Subscribe to this mod's changes

biome is a skill published in the GitHub repository ai-ecoverse/slicc (30 stars, last pushed today), licensed Apache-2.0. It adds 52 tokens to every session and 589 once invoked, about $0.0003 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 2026-09-05.