truthmark: Skill for Claude Code

.agents/skills/truthmark-check/SKILL.md

truthmark-check is a skill for Claude Code, Codex from merlinhu1/truthmark. It costs 55 tokens per session (248 once invoked), scanned A, original, MIT.

A skill that audits whether a repository’s canonical documentation, ownership, and routing structure accurately reflect the codebase. It reports problems instead of silently rewriting unrelated files.

In plain words
What is it for?
Use it to check documentation health and receive a report of issues and suggested fixes; it is not a normal code linting or testing tool.
Why use it?
It helps find missing, misplaced, outdated, or ambiguously owned documentation before those problems cause confusion.

Skill for Claude CodeCodex

Written for Claude Code and Codex: user-invocable in frontmatter, but also agents/openai.yaml present. Also seen: mentions subagents; installed under .agents/ (shared by several agents).

This is merlinhu1/truthmark's own configuration. It tells Claude Code and Codex how to work on truthmark itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything truthmark configures →

Reuse

Borrowing it

Nothing to install: this file belongs to merlinhu1/truthmark. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/merlinhu1/truthmark/main/.agents/skills/truthmark-check/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/merlinhu1/truthmark

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 truthmark-check

README.md
[![agentmods](https://agentmods.dev/badge/skills/merlinhu1/truthmark/truthmark-check/github.svg)](https://agentmods.dev/skills/merlinhu1/truthmark/truthmark-check)
Your own site
<a href="https://agentmods.dev/skills/merlinhu1/truthmark/truthmark-check"><img src="https://agentmods.dev/badge/skills/merlinhu1/truthmark/truthmark-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 truthmark-check

Your own site · 80×15
<a href="https://agentmods.dev/skills/merlinhu1/truthmark/truthmark-check"><img src="https://agentmods.dev/badge/skills/merlinhu1/truthmark/truthmark-check.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 248 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
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 $0.00055 $0.00248
Opus 5.5 $0.00022 $0.00099
Sonnet 5.5 $0.00011 $0.00050
Haiku 4.5 $0.00006 $0.00025

Measured 1mo ago against content hash 1061faa37c77, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

truthmark-check 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 1mo 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.

.agents/skills/truthmark-check/SKILL.md · 20 lines

What it actually says

Truthmark Check

Use this skill to audit repository truth health.

Quick procedure:

  • Inspect .truthmark/config.yml and configured route files (docs/truthmark/routes/areas.md; docs/truthmark/routes/areas/) only when they exist; then inspect canonical docs and relevant implementation directly.
  • Report issues and suggested fixes; do not silently rewrite unrelated files.

Reference files:

  • Procedure: core review questions; read before edits or detailed auditing. See procedure.md.
  • Report template: read before writing the final report. See report-template.md.
  • Subagents and leases: read only when using subagents, leases, or accepting worker output. See subagents-and-leases.md.
Files

What ships with it

4 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. 1mo ago Changed · -1 lines · +12 tokens per session 1061faa37c77
  2. 2mo ago First seen · 21 lines · 43 tokens per session scan A 5659cbfc6296

Subscribe to this mod's changes

truthmark-check is a skill published in the GitHub repository merlinhu1/truthmark (91 stars, last pushed 1mo ago), licensed MIT. It adds 55 tokens to every session and 248 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-30.

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