skill-maintainer

skill-maintainer is a skill for Claude Code, Codex from moonlight-lupin/agent-skills. It costs 12 tokens per session (4,665 once invoked), scanned A, original, MIT.

A maintenance workflow for people who manage a collection of coding-agent skills. It tracks skills adapted from elsewhere, checks for changes upstream, and supports updating and publishing the collection.

In plain words
What is it for?
Use it when creating or importing skills, checking for upstream drift, finding untracked dependencies, publishing updates, scheduling regular sync checks, or pruning a large library.
Why use it?
It helps prevent local skills from becoming outdated or losing changes from their original sources. It also keeps a growing skill library organized and its external dependencies visible.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions subagents.

Good fit Use it when creating or importing skills, checking for upstream drift, finding untracked dependencies, publishing updates, scheduling regular sync checks, or pruning a large library.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/moonlight-lupin/agent-skills/skill-maintainer
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 moonlight-lupin/agent-skills --skill skill-maintainer
Clone the repo
git clone --depth 1 https://github.com/moonlight-lupin/agent-skills

Made for: Claude Code, Codex.

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 skill-maintainer

README.md
[![agentmods](https://agentmods.dev/badge/skills/moonlight-lupin/agent-skills/skill-maintainer/github.svg)](https://agentmods.dev/skills/moonlight-lupin/agent-skills/skill-maintainer)
Your own site
<a href="https://agentmods.dev/skills/moonlight-lupin/agent-skills/skill-maintainer"><img src="https://agentmods.dev/badge/skills/moonlight-lupin/agent-skills/skill-maintainer/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for skill-maintainer

Your own site · 80×15
<a href="https://agentmods.dev/skills/moonlight-lupin/agent-skills/skill-maintainer"><img src="https://agentmods.dev/badge/skills/moonlight-lupin/agent-skills/skill-maintainer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 12 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,665 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 Data Exfiltration · line 291
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
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 $0.00012 $0.04665
Opus 5 $0.00006 $0.02332
Sonnet 5 $0.00002 $0.00933
Haiku 4.5 $0.00001 $0.00466

Measured 10d ago against content hash 9a733ef88108, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

skill-maintainer scanned grade A with 1 finding 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 10d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/upstream_check.py, tests/test_upstream_check.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

# windows: cron + curl available via WSL/MSYS2, but untested on native Win32
agent-ops/skill-maintainer/SKILL.md · 515 lines

How it starts

The opening of the file, as written. The whole thing — 515 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skill Maintainer

Overview

A meta-skill for agents who maintain a library of skills — their own, adapted from external repos, or published to a shared repo. Covers the full lifecycle: authoring → curating → tracking → syncing → publishing.

This skill encodes a workflow built and battle-tested across dozens of skills. It is agent-agnostic: replace tool names (e.g. write_file, terminal, delegate_task) with your platform's equivalents. The patterns — manifest tracking, layered sync, parallel diff dispatch, cron-based drift detection — transfer to any agent runtime.

When to Use

  • Creating a new skill from scratch
  • Importing/adapting skills from an external repo or collection
  • Checking if local skills have drifted from upstream
  • Scanning for untracked external tool dependencies
  • Publishing a local skill to a shared repo
  • Setting up automated monthly sync checks
  • Tightening/pruning an accumulated skill library

Don't use for: one-off skill creation with no upstream tracking need (just use your platform's skill-authoring tool directly). This skill adds value when you have ≥5 skills or ≥1 external dependency to track.

Core Concepts

The three sync layers

Layer Direction What drifts Example
1. External → Local Upstream repo → your skill Upstream adds features, fixes bugs, changes API baoyu-skills v1.56 → v1.117
2. Local → Published repo Your skill → your GitHub repo You improve locally; repo copy goes stale skill gets new flags locally; repo doesn't
3. Local → Standalone repo Your skill → a code project repo Skill documents a workflow; the code evolves skill describes CLI v1; CLI is now v3

All three need tracking. Layer 1 is the most common concern. Layer 2 is the most commonly forgotten — publish once, keep improving, repo goes stale.

The manifest

A single UPSTREAM_MANIFEST.md file at your skills root tracks every skill with external provenance. One row per skill, covering all three layers. See templates/upstream-manifest.md for the file format.

Read the full file on GitHub · 515 lines

Files

What ships with it

3 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.

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. 10d ago First seen · 515 lines · 12 tokens per session scan A 9a733ef88108

Subscribe to this mod's changes

skill-maintainer is a skill published in the GitHub repository moonlight-lupin/agent-skills (60 stars, last pushed 3d ago), licensed MIT. It adds 12 tokens to every session and 4,665 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.