health

health is a skill for Claude Code from eunji-jessi-jung/reef. It costs 5 tokens per session (2,075 once invoked), scanned A, original, Apache-2.0.

A read-only checker for a reef of linked project artifacts, such as research notes or specifications. It validates references, required metadata, source files, and whether artifacts are becoming outdated.

In plain words
What is it for?
Use it to lint a .reef project and compare its artifacts for freshness, then follow its instructions to refresh problems with a separate update command.
Why use it?
It shows broken links, missing source files, invalid structure, and stale content without changing the artifacts.

Skill for Claude Code

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the reef plugin — 11 skills, 1 agent shipped together

Good fit Use it to lint a .reef project and compare its artifacts for freshness, then follow its instructions to refresh problems with a separate update command.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add eunji-jessi-jung/reef
Claude Code
/plugin install reef

Made for: Claude Code.

Or install reef, the plugin that ships this one along with the rest of its 11 skills, 1 agent.

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

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/eunji-jessi-jung/reef/health"><img src="https://agentmods.dev/badge/skills/eunji-jessi-jung/reef/health.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 5 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,075 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00005 $0.02075
Opus 5 $0.00003 $0.01038
Sonnet 5 $0.00001 $0.00415
Haiku 4.5 $0.00001 $0.00208

Measured 12d ago against content hash 0f45da7a6530, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

health 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 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.

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.

skills/health/SKILL.md · 197 lines

How it starts

The opening of the file, as written. The whole thing — 197 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/reef:health

Read-only validation and freshness report. This skill does NOT modify artifacts. To fix issues, run /reef:update.

Setup

Read these references before doing anything else:

  • ${CLAUDE_PLUGIN_ROOT}/references/artifact-contract.md
  • ${CLAUDE_PLUGIN_ROOT}/references/methodology.md

Voice

Curious Researcher. Use reef metaphor for status ("Your reef is aging", "3 artifacts growing stale"). Plain language for actions ("Run /reef:update to refresh"). No emojis. No exclamation marks.

Procedure

1. Locate the reef

Find the .reef/ directory in cwd or parents. Read project.json from the reef root.

2. Run script checks

Run both commands:

python3 ${CLAUDE_PLUGIN_ROOT}/scripts/reef.py lint --reef <reef-root>
python3 ${CLAUDE_PLUGIN_ROOT}/scripts/reef.py diff --reef <reef-root>

These cover the seven mechanical checks:

  1. Orphan detection — artifacts with no incoming relates_to (except SYS- roots, which are natural entry points).
  2. Dangling referencesrelates_to targets that do not resolve to an existing artifact file.
  3. Source file existencesources refs that no longer exist on disk.
  4. Frontmatter schema — required fields present, valid enum values, id matches filename.
  5. Key Facts without source links — Key Facts missing the citation syntax.
  6. Wikilink/frontmatter sync## Related wikilinks do not match relates_to entries.
  7. Freshness — source files changed on disk since the artifact's last write time.

3. Format the report

Render the health report as a text table using Unicode box-drawing characters. The report has three sections: domain coverage (headline), artifact health, and source detail (secondary).

Section 1 — Artifact Topology (headline)

Show a heatmap matrix of artifact density by service and type. This gives the user an instant visual of where the reef is deep vs thin.

Use shaded block characters to represent density:

  • (empty) = 0 artifacts
  • = 1-2
  • = 3-4
  • = 5-6
  • = 7+

Read the full file on GitHub · 197 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 · 197 lines · 5 tokens per session scan A 0f45da7a6530

Subscribe to this mod's changes

health is a skill published in the GitHub repository eunji-jessi-jung/reef (5 stars, last pushed 4mo ago), licensed Apache-2.0. It adds 5 tokens to every session and 2,075 once invoked, about $0.0000 per session on Opus 5. 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.

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