check-skills

check-skills is a command for Claude Code from zhiganov/skill-drift. It costs 18 tokens per session (2,481 once invoked), scanned B, original, MIT.

A read-only report command that checks installed skills for stale updates, missing links, or unknown origins.

In plain words
What is it for?
Running a full report, producing JSON, checking without network access, refreshing the cache, or emitting a session-start status banner.
Why use it?
It shows which skills are active, where they came from, and whether their status can be verified without changing them.

Command for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: reads .claude/ paths; mentions subagents; mentions Claude Code.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is node scripts/check-skills.mjs $ARGUMENTS.

Good fit Running a full report, producing JSON, checking without network access, refreshing the cache, or emitting a session-start status banner.

Compare 6 commands from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/zhiganov/skill-drift
agentmods
npx agentmods add commands/zhiganov/skill-drift/check-skills

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 check-skills

README.md
[![agentmods](https://agentmods.dev/badge/commands/zhiganov/skill-drift/check-skills/github.svg)](https://agentmods.dev/commands/zhiganov/skill-drift/check-skills)
Your own site
<a href="https://agentmods.dev/commands/zhiganov/skill-drift/check-skills"><img src="https://agentmods.dev/badge/commands/zhiganov/skill-drift/check-skills/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 check-skills

Your own site · 80×15
<a href="https://agentmods.dev/commands/zhiganov/skill-drift/check-skills"><img src="https://agentmods.dev/badge/commands/zhiganov/skill-drift/check-skills.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 18 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,481 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00018 $0.02481
Opus 5 $0.00009 $0.01241
Sonnet 5 $0.00004 $0.00496
Haiku 4.5 $0.00002 $0.00248

Measured 2d ago against content hash 4ee7ed600b87, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade B, and why

check-skills scanned grade B 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 2d 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.

Reads agent configuration directoriesmediumAgent snooping

.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.

Installing it on a new machine (machine-local — `~/.claude/settings.json` is not synced):
commands/check-skills.md · 160 lines

How it starts

The opening of the file, as written. The whole thing — 160 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Check skills

Skills have no update banner, unlike plugins. This is the substitute: one read-only pass over every install mechanism on this machine, answering what is active, where did it come from, and is any of it behind?

Run it

node scripts/check-skills.mjs $ARGUMENTS
Flag Effect
(none) Full report, refreshes the cache
--json Machine-readable output
--no-network Skip every remote call — everything becomes "undeterminable" rather than falsely reading as current
--banner Session-start hook mode. Cache only, no network. Emits a JSON object or nothing — not for humans.
--refresh Run the check, write the cache, print nothing

Then show the user the report as-is. It is already formatted for a terminal — do not re-summarise it into a table of your own.

The session-start banner

A SessionStart hook runs --banner, which reads only the cache — no network, no git, no npm, ~75ms. If the cache is older than roots.cacheTtlHours (default 24) it spawns a detached refresh whose result appears next session. Session start never waits on ~25 GitHub calls.

It emits one JSON object, or nothing. It fires only on states that are actionable now: something behind upstream, something in the repo not linked on this machine, or the checkout behind origin. Provenance gaps (undeterminable, unattributed) are deliberately excluded — they are real but near-permanent, and a banner that fires on a healthy machine every session is one you learn to scroll past.

It must be JSON, not plain text. A SessionStart hook's plain stdout is added to Claude's context, not shown to the user — that is documented behaviour for SessionStart, UserPromptSubmit and UserPromptExpansion, and it is the opposite of what a banner needs. The only field that surfaces text to the person at the keyboard is systemMessage. The first version of this shipped as plain text and was therefore invisible to its entire audience.

Read the full file on GitHub · 160 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. 2d ago Changed · +15 lines 4ee7ed600b87
  2. 9d ago First seen · 145 lines · 18 tokens per session scan B 3c71fac5402f

Subscribe to this mod's changes

check-skills is a command published in the GitHub repository zhiganov/skill-drift (2 stars, last pushed 4d ago), licensed MIT. It adds 18 tokens to every session and 2,481 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it B with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.