Borrowing it
Nothing to install: this file belongs to AppsVortex/arness. 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/AppsVortex/arness/main/CLAUDE.mdgit clone --depth 1 https://github.com/AppsVortex/arnessWrote 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/appsvortex/arness/claude-md)<a href="https://agentmods.dev/instructions/appsvortex/arness/claude-md"><img src="https://agentmods.dev/badge/instructions/appsvortex/arness/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/appsvortex/arness/claude-md"><img src="https://agentmods.dev/badge/instructions/appsvortex/arness/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 | $0.03527 | $0.03527 |
| Opus 5.5 | $0.01411 | $0.01411 |
| Sonnet 5.5 | $0.00705 | $0.00705 |
| Haiku 4.5 | $0.00353 | $0.00353 |
Grade A, and why
arness 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.
How it starts
The opening of the file, as written. The whole thing — 194 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
Project Purpose
Arness is a plugin marketplace for Claude Code containing three independently installable plugins for development, greenfield exploration, and infrastructure. The repository is itself a valid Claude Code marketplace, so plugins can be tested locally.
Architecture
arness/ # Marketplace repository
├── .claude-plugin/
│ └── marketplace.json # Marketplace catalog (lists all 3 plugins)
├── plugins/
│ ├── arn-code/ # Core development plugin
│ │ ├── .claude-plugin/plugin.json
│ │ ├── skills/ # 25 pipeline skills
│ │ └── agents/ # 14 specialist agents
│ ├── arn-spark/ # Greenfield exploration plugin
│ │ ├── .claude-plugin/plugin.json
│ │ ├── skills/ # 19 exploration skills
│ │ └── agents/ # 13 specialist agents
│ └── arn-infra/ # Infrastructure plugin
│ ├── .claude-plugin/plugin.json
│ ├── skills/ # 23 infrastructure skills
│ └── agents/ # 9 specialist agents
└── assets/ # Shared assets (banner, etc.)
Key rule: All plugin component directories (skills/, agents/) must be at the plugin root, NOT inside .claude-plugin/.
Template Management
When updating default report templates in plugins/arn-code/skills/arn-code-save-plan/report-templates/default/:
- Make changes to the template JSON files
- Bump the plugin's
versionin the corresponding entry of.claude-plugin/marketplace.json(the marketplace entry is the authoritative version source —plugin.jsonintentionally omitsversionper commit d3434de, see the "Versioning" section below) - Test by running
arn-code-initin a test project -- templates will be copied and fresh checksums generated - Projects using the previous version will be prompted to update on next Arness skill invocation (behavior depends on their
Template updatespreference)
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 · 194 lines · 3,527 tokens per session scan A bd1cc9318352
arness CLAUDE.md is an instructions file published in the GitHub repository AppsVortex/arness (33 stars, last pushed 2mo ago), licensed MIT. It adds 3,527 tokens to every session, about $0.0141 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.
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).
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.