Borrowing it
Nothing to install: this file belongs to getskillseal/skillseal. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/getskillseal/skillseal/main/CLAUDE.mdgit clone --depth 1 https://github.com/getskillseal/skillsealWrote 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.
[](https://agentmods.dev/instructions/getskillseal/skillseal/claude-md)<a href="https://agentmods.dev/instructions/getskillseal/skillseal/claude-md"><img src="https://agentmods.dev/badge/instructions/getskillseal/skillseal/claude-md/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.
<a href="https://agentmods.dev/instructions/getskillseal/skillseal/claude-md"><img src="https://agentmods.dev/badge/instructions/getskillseal/skillseal/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00331 | $0.00331 |
| Opus 5.5 | $0.00132 | $0.00132 |
| Sonnet 5.5 | $0.00066 | $0.00066 |
| Haiku 4.5 | $0.00033 | $0.00033 |
Grade A, and why
skillseal CLAUDE.md 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.
What it actually says
CLAUDE.md
Guidance for Claude and other agents working in this repository.
What this is
SkillSeal is a natural evolution of Agent Skills:
the same portable folder with a SKILL.md, plus a seal — one short line that
proves the fingerprint, the publisher key, and the signature before anything is
written. A sealed skill stays a plain Agent Skills folder, so it is backward
compatible by construction.
Layout
skillseal/ the CLI and library (npm: skillseal) — the product
skills-ref/ reference skills, each a folder with a SKILL.md
web/hub/ the Sealed Skills browser (static)
web/site/ the docs site (static)
docs/ design notes and assets
demo/ a runnable security demo, proof in demo/evidence/
Working here
- The install line and the manifest live in
skillseal/. Anything touching them needs a test inskillseal/test/. - A sealed skill must stay a plain Agent Skills folder. Backward compatibility is not negotiable.
- Keep the surface small and the prose plain. A change that adds a folder or a flag should earn it.
- See AGENTS.md for how an agent installs and uses a sealed skill.
Verify your changes
node skillseal/test/v2.test.mjs # the CLI test suite
./demo/demo.sh # the security demo
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.
- 1mo ago First seen · 40 lines · 331 tokens per session scan A fc338b8c83db
skillseal CLAUDE.md is an instructions file published in the GitHub repository getskillseal/skillseal (2 stars, last pushed 2mo ago), licensed MIT. It adds 331 tokens to every session, about $0.0013 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 2026-08-31.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
vscode model-prompts.instructions.md
Model-specific prompt authoring and registry guidelines.