ruff

A tool for checking and formatting Python code with Ruff, a program that finds common code problems and applies consistent formatting. It runs through uv, a Python project and package manager.

In plain words
What is it for?
Use it to check a Python project, automatically fix supported lint problems, format its files, or verify that formatting is already correct.
Why use it?
It catches style and basic code issues early and keeps files formatted consistently. Automatic fixes can remove some problems without editing each file by hand.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/rootwarp/claude-code-plugins-monorepo/ruff
Any agent
npx skills add rootwarp/claude-code-plugins-monorepo --skill ruff
Clone the repo
git clone --depth 1 https://github.com/rootwarp/claude-code-plugins-monorepo

Made for: Claude Code, Codex.

Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 148 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00000 $0.00148
Opus 5 $0.00000 $0.00074
Sonnet 5 $0.00000 $0.00030
Haiku 4.5 $0.00000 $0.00015

Measured yesterday against content hash e43b6fc57eb0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

ruff 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 yesterday.

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.

plugins/python/skills/ruff/SKILL.md · 44 lines

What it actually says

/ruff

Run Ruff linter and formatter on the Python project using uv.

Instructions

Linting

Check for lint issues:

uv run ruff check .

Auto-fix issues where possible:

uv run ruff check --fix .

Formatting

Format all Python files (79 char line limit per PEP 8):

uv run ruff format .

Check formatting without making changes:

uv run ruff format --check .

Combined

Run both check and format:

uv run ruff check --fix . && uv run ruff format .

Analyze any lint warnings or errors and suggest fixes.

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. yesterday First seen · 44 lines · 0 tokens per session scan A e43b6fc57eb0

Subscribe to this mod's changes

ruff is a skill published in the GitHub repository rootwarp/claude-code-plugins-monorepo (2 stars, last pushed 4mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 148 tokens. 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 2026-08-31.

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