health-check

health-check is a skill for Claude Code, Codex from jasonkneen/lazar. It costs 107 tokens per session (2,935 once invoked), scanned C, original, MIT.

A verification procedure for checking whether Lazar is installed correctly and whether its important behaviors work from start to finish.

In plain words
What is it for?
Use it after installation, setup changes, resets, kernel rebuilds, or whenever Lazar behaves unexpectedly.
Why use it?
It can expose configuration, sandbox, logging, memory, recursion, or build problems before they affect real work.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: positional $N argument.

Good fit Use it after installation, setup changes, resets, kernel rebuilds, or whenever Lazar behaves unexpectedly.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/jasonkneen/lazar/health-check
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 jasonkneen/lazar --skill health-check
Clone the repo
git clone --depth 1 https://github.com/jasonkneen/lazar

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 health-check

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/jasonkneen/lazar/health-check"><img src="https://agentmods.dev/badge/skills/jasonkneen/lazar/health-check.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 107 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,935 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 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 $0.00107 $0.02935
Opus 5 $0.00053 $0.01468
Sonnet 5 $0.00021 $0.00587
Haiku 4.5 $0.00011 $0.00294

Measured 12d ago against content hash 413f63b39acf, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade C, and why

health-check scanned grade C 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 12d 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.

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

rm -rf "$HC"
src/seed-skills/_meta/health-check/SKILL.md · 257 lines

How it starts

The opening of the file, as written. The whole thing — 257 lines — stays where its author put it; the contents beside it link to each section on GitHub.

health-check

Verify lazar is installed correctly and all the load-bearing behaviors work end-to-end. Runs in a temp directory so it doesn't pollute real state.

When to use

  • Right after install or setup.sh, to confirm everything works.
  • After a kernel rebuild, to verify the patch didn't break anything.
  • After --reset-all, to validate fresh state.
  • When something feels off and you want a baseline.
  • Periodically as a smoke test before a long session.

How to use

Run the recipes in order. Each check prints [PASS], [FAIL: <reason>], or [SKIP: <reason>] for things that aren't applicable on this system. Print a summary at the end with the PASS/FAIL count.

If any FAIL appears, the user should investigate before doing real work — most failures point at a misconfiguration that will silently bite later.

Setup

HC="$LAZAR_HOME/workspace/.health-check-$(date +%s)"
mkdir -p "$HC"
echo "[health-check] starting in $HC"
PASS=0; FAIL=0; SKIP=0
pass() { echo "  [PASS] $1"; PASS=$((PASS+1)); }
fail() { echo "  [FAIL] $1"; FAIL=$((FAIL+1)); }
skip() { echo "  [SKIP] $1"; SKIP=$((SKIP+1)); }

1. Static checks (kernel + filesystem)

echo "── 1. static checks ────────────────────────────────"

# kernel binary
[ -f "$LAZAR_HOME/bin/lazar" ] && pass "kernel binary at bin/lazar" || fail "no kernel binary"

# kernel locked (macOS chflags uchg)
ls -lO "$LAZAR_HOME/bin/lazar" 2>/dev/null | rg -q uchg \
    && pass "kernel binary is uchg-locked (immutable)" \
    || fail "kernel binary is NOT immutable — chflags uchg should be set"

# source not user-writable
TESTSRC="$LAZAR_HOME/src/.health-write-probe"
touch "$TESTSRC" 2>/dev/null && { rm -f "$TESTSRC"; fail "src/ is writable — should be chmod a-w"; } \
    || pass "src/ is read-only"

# env vars from kernel
[ -n "$LAZAR_HOME" ]      && pass "LAZAR_HOME=$LAZAR_HOME"           || fail "LAZAR_HOME unset"
[ -n "$LAZAR_SKILLS" ]    && pass "LAZAR_SKILLS=$LAZAR_SKILLS"       || fail "LAZAR_SKILLS unset"
[ -n "$LAZAR_MEMORY" ]    && pass "LAZAR_MEMORY=$LAZAR_MEMORY"       || fail "LAZAR_MEMORY unset"
[ -n "$LAZAR_WORKSPACE" ] && pass "LAZAR_WORKSPACE=$LAZAR_WORKSPACE" || fail "LAZAR_WORKSPACE unset"
[ -n "$LAZAR_LOGS" ]      && pass "LAZAR_LOGS=$LAZAR_LOGS"           || fail "LAZAR_LOGS unset"

# api key
[ -n "$ANTHROPIC_API_KEY" ] && pass "ANTHROPIC_API_KEY is set" || fail "ANTHROPIC_API_KEY not set"

# seed skills present in live skills/
for s in create-skill find-capability shell-handoff load-context log-rotation archive-search distill propose-kernel-patch project-context create-tui health-check; do
    [ -f "$LAZAR_SKILLS/_meta/$s/SKILL.md" ] && pass "skill _meta/$s" || fail "skill _meta/$s missing"
done
[ -f "$LAZAR_SKILLS/memory/SKILL.md" ] && pass "skill memory" || fail "skill memory missing"
[ -f "$LAZAR_SKILLS/INDEX.md" ]        && pass "skills/INDEX.md present" || fail "INDEX.md missing"

Read the full file on GitHub · 257 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. 12d ago First seen · 257 lines · 107 tokens per session scan C 413f63b39acf

Subscribe to this mod's changes

health-check is a skill published in the GitHub repository jasonkneen/lazar (31 stars, last pushed 1mo ago), licensed MIT. It adds 107 tokens to every session and 2,935 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it C with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

reproduce-bug

Reproduce a reported bug in googleapis/mcp-toolbox and decide whether it is real, delivering an evidence-backed verdict: confirmed, already fixed, misconfiguration, client-side, works as intended, not reproducible, or blocked. Use whenever a maintainer asks you to reproduce, verify, confirm, or investigate a bug…

googleapis/mcp-toolbox · 130 tokens

verify-bug

Post-merge UAT verification workflow. Walks JIRA reproduce steps, performs comparative audits (Before/After), attaches evidence to JIRA, and transitions status on PASS.

HoangNguyen0403/agent-skills-standard · 39 tokens

reality-verification

This skill should be used when the user asks to "verify a fix", "reproduce failure", "diagnose issue", "check BEFORE/AFTER state", "VF task", "reality check", "check test quality", "mock-only tests", or needs guidance on verifying fixes by reproducing failures before and after implementation, or detecting mock-heavy…

tzachbon/smart-ralph · 81 tokens

testing-blocks

Use this when you have made AEM Edge Delivery Services code changes to blocks, scripts, or styles and need to validate them before opening a pull request. Covers unit testing for utilities and logic, browser testing with Playwright, linting, and guidance on what to test and how.

adobe/skills · 61 tokens

test-electron-app

Drive the real running PostHog Electron app (live tRPC, workspace-server, real data) over CDP with agent-browser. Connect to the running app on port 9222, test desktop changes against a local Django stack, snapshot the accessibility tree, inspect network requests, and screenshot only when explicitly asked. Use when…

PostHog/posthog · 112 tokens

qa

Read-only automated QA sweep of a deployed stardust site on AEM Edge Delivery Services — validates routing, content fidelity vs the source capture, template conformance, rendered integrity (geometry, JS errors, broken images), visual regression vs baselines, metadata/SEO/JSON-LD, link integrity, accessibility (axe)…

adobe/skills · 138 tokens