Borrowing it
Nothing to install: this file belongs to saski/arnesto. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/saski/arnesto/main/.agents/skills/using-uv/SKILL.mdgit clone --depth 1 https://github.com/saski/arnestoWrote 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.
[](https://agentmods.dev/skills/saski/arnesto/using-uv)<a href="https://agentmods.dev/skills/saski/arnesto/using-uv"><img src="https://agentmods.dev/badge/skills/saski/arnesto/using-uv.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00025 | $0.00342 |
| Opus 5 | $0.00013 | $0.00171 |
| Sonnet 5 | $0.00005 | $0.00068 |
| Haiku 4.5 | $0.00003 | $0.00034 |
Grade A, and why
using-uv 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.
This is a copy
100% identical to using-uv — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
What it actually says
UV
UV is a fast Python package manager. Two modes:
Scripts vs Projects
Use scripts when:
- Single .py file
- Quick utility, one-off task
- No shared dependencies across files
Use projects when:
- Multiple files, modules, or packages
- Team collaboration
- Need reproducible environments
- Building a library or application
Scripts
Standalone Python files with inline dependencies (PEP 723).
#!/usr/bin/env -S uv run --script
# /// script
# requires-python = ">=3.12"
# dependencies = ["requests", "rich"]
# ///
import requests
from rich import print
Run: uv run script.py
See references/scripts.md for full guide.
Projects
Structured Python with pyproject.toml and lockfile.
uv init myproject
cd myproject
uv add requests
uv run python main.py
Key files:
pyproject.toml- metadata and dependenciesuv.lock- exact versions for reproducibility.python-version- Python version
See references/projects.md for full guide.
Common Patterns
uv run pytest # Run in project env
uv add --dev pytest # Dev dependency
uvx ruff check . # One-off tool execution
uv run --with rich script.py # Script with ad-hoc dep
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 3d ago First seen · 68 lines · 25 tokens per session scan A d70d890eb88d
using-uv is a skill published in the GitHub repository saski/arnesto (5 stars, last pushed today), licensed Unlicense. It adds 25 tokens to every session and 342 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to using-uv, differing in 0 lines, and is treated as a copy.
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