uv-tool-usage

A set of rules for using uv, a Python tool that creates environments, installs packages, runs scripts, and manages project dependencies.

In plain words
What is it for?
Use it to start projects, add or remove dependencies, create lockfiles, install locked dependencies, run commands, build packages, and publish them to PyPI.
Why use it?
It gives Python projects one consistent way to manage packages and environments instead of mixing commands from tools such as pip and Poetry.

Cursor rule for Cursor

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 rules/mitas/cursor-rules/uv-tool-usage
Clone the repo
git clone --depth 1 https://github.com/mitas/cursor-rules

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 1,297 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 $0.01297
Opus 5 $0.00000 $0.00648
Sonnet 5 $0.00000 $0.00259
Haiku 4.5 $0.00000 $0.00130

Measured yesterday against content hash 1dff065243ff, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

uv-tool-usage 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.

.cursor/rules/uv-tool-usage.mdc · 139 lines

How it starts

The opening of the file, as written. The whole thing — 139 lines — stays where its author put it; the contents beside it link to each section on GitHub.

UV Tool Usage

Basic Commands

  • Create virtual environments with: uv venv instead of python -m venv
  • Install packages with: uv pip install package instead of pip install package
  • Run Python scripts with: uv run python script.py instead of python script.py
  • Initialize a new project: uv init myproject
  • Generate lockfile: uv lock
  • Install dependencies from lockfile: uv sync
  • Run commands in project environment: uv run command

Project Management

  • Use uv for all project management: uv init myproject
  • Create standard project structure with:
    • pyproject.toml - Project configuration
    • src/ - Source code directory
    • .venv/ - Virtual environment (created when needed)
    • uv.lock - Lockfile for dependencies
  • Add dependencies with: uv add package
  • Add dev dependencies with: uv add --dev package
  • Remove dependencies with: uv remove package
  • Update dependencies with: uv update
  • Show installed packages with: uv list

Package Management

  • Build packages with: uv build
  • Publish to PyPI with: uv publish
  • Manage dependencies with uv instead of poetry or pip-tools:
    • uv pip compile pyproject.toml -o requirements.txt to generate requirements
    • uv sync to install dependencies from lockfile (preferred method)
    • uv pip sync requirements.txt as alternative for requirements.txt files

Python Version Management

  • Install specific Python versions: uv python install 3.11
  • List installed Python versions: uv python list
  • Pin project to a Python version: uv python pin 3.11
  • Create virtual environment with specific Python: uv venv --python 3.12.0
  • Use specific Python version: uv run --python 3.11 script.py

Tool Management

  • Run tools in ephemeral environments with: uvx tool-name (e.g., uvx pytest)
  • Install tools globally with: uv tool install ruff
  • List installed tools with: uv tool list
  • Uninstall tools with: uv tool uninstall ruff
  • Run Python-based tools without installing: uvx tool-name

Read the full file on GitHub · 139 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. yesterday First seen · 139 lines · 1,297 tokens per session scan A 1dff065243ff

Subscribe to this mod's changes

uv-tool-usage is a cursor rule published in the GitHub repository mitas/cursor-rules (2 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,297 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.