Borrowing it
Nothing to install: this file belongs to Chachamaru127/codex-harness. 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/Chachamaru127/codex-harness/main/.codex/skills/principles/SKILL.mdgit clone --depth 1 https://github.com/Chachamaru127/codex-harnessWrote 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/skills/chachamaru127/codex-harness/principles)<a href="https://agentmods.dev/skills/chachamaru127/codex-harness/principles"><img src="https://agentmods.dev/badge/skills/chachamaru127/codex-harness/principles.svg" alt="Measured on agentmods" 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 | $0.00052 | $0.00367 |
| Opus 5 | $0.00026 | $0.00183 |
| Sonnet 5 | $0.00010 | $0.00073 |
| Haiku 4.5 | $0.00005 | $0.00037 |
Grade A, and why
principles 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 6d 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
Principles Skills
開発原則とガイドラインを提供するスキル群です。
機能詳細
| 機能 | 詳細 |
|---|---|
| 基本原則 | See references/general-principles.md |
| 差分編集 | See references/diff-aware-editing.md |
| コンテキスト読み取り | See references/repo-context-reading.md |
| VibeCoder | See references/vibecoder-guide.md |
実行手順
- ユーザーのリクエストを分類
- 上記の「機能詳細」から適切な参照ファイルを読む
- その内容を参照・適用
What ships with it
5 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.
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.
- 6d ago First seen · 28 lines · 52 tokens per session scan A 7e13e96cb271
principles is a skill published in the GitHub repository Chachamaru127/codex-harness (2 stars, last pushed 6mo ago), licensed MIT. It adds 52 tokens to every session and 367 once invoked, about $0.0003 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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