Borrowing it
Nothing to install: this file belongs to harnessprotocol/harness-kit. 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/harnessprotocol/harness-kit/main/CLAUDE.mdgit clone --depth 1 https://github.com/harnessprotocol/harness-kitWrote 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/harnessprotocol/harness-kit/claude-md)<a href="https://agentmods.dev/instructions/harnessprotocol/harness-kit/claude-md"><img src="https://agentmods.dev/badge/instructions/harnessprotocol/harness-kit/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/harnessprotocol/harness-kit/claude-md"><img src="https://agentmods.dev/badge/instructions/harnessprotocol/harness-kit/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 | $0.01579 | $0.01579 |
| Opus 5.5 | $0.00632 | $0.00632 |
| Sonnet 5.5 | $0.00316 | $0.00316 |
| Haiku 4.5 | $0.00158 | $0.00158 |
Grade A, and why
harness-kit 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 — 163 lines — stays where its author put it; the contents beside it link to each section on GitHub.
harness-kit
Claude Code configuration — skills, agents, and settings worth sharing, distributed as a plugin marketplace.
Repo structure
harness-kit/
├── .claude-plugin/
│ └── marketplace.json ← marketplace catalog
├── .github/
│ ├── schema/
│ │ └── plugin.schema.json ← Protocol JSON Schema for plugin manifest validation
│ └── workflows/
│ └── validate.yml ← CI: manifest parsing, version alignment, schema validation, builds, tests
├── plugins/ ← 17 plugins; see .claude-plugin/marketplace.json for full list
├── packages/ ← shared libraries
│ ├── core/ ← harness.yaml compile/parse/detect logic
│ ├── shared/ ← shared TypeScript types used across apps
│ ├── design-tokens/ ← single source of truth for the shared color identity; generates CSS vars for app + website
│ └── marketplace-data/ ← build-time generator: git → static marketplace JSON (runs the security scanner)
├── functions/ ← Cloudflare Pages Functions (server-side endpoints, e.g. /feedback proxy)
├── website/ ← documentation site + plugin marketplace (harnesskit.ai)
├── homebrew/ ← Homebrew tap formulae for CLI and desktop app
├── apps/ ← end-user applications
│ ├── desktop/ ← Tauri desktop app (React + Rust)
│ └── cli/ ← harness CLI
├── profiles/ ← pre-configured harness.yaml bundles for different roles
├── evals/ ← automated skill evaluation framework (Python + golden responses)
├── harness.yaml ← dogfooding config (plugins used to develop this repo)
├── install.sh ← script fallback for users without plugin marketplace
├── CLAUDE.md ← this file
└── README.md
Adding a new plugin
1. Create the plugin directory
plugins/<plugin-name>/
├── .claude-plugin/
│ └── plugin.json
├── agents/ ← optional, for specialist subagents
├── scripts/ ← optional, for bundled utilities
└── skills/
└── <skill-name>/
├── SKILL.md
└── README.md
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 · 163 lines · 1,579 tokens per session scan A e12345b5887b
harness-kit CLAUDE.md is an instructions file published in the GitHub repository harnessprotocol/harness-kit (10 stars, last pushed 2d ago), licensed Apache-2.0. It adds 1,579 tokens to every session, about $0.0063 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.
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