Borrowing it
Nothing to install: this file belongs to jvogan/a-fable-of-codexes. 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/jvogan/a-fable-of-codexes/main/CLAUDE.mdgit clone --depth 1 https://github.com/jvogan/a-fable-of-codexesWrote 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/jvogan/a-fable-of-codexes/claude-md)<a href="https://agentmods.dev/instructions/jvogan/a-fable-of-codexes/claude-md"><img src="https://agentmods.dev/badge/instructions/jvogan/a-fable-of-codexes/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/jvogan/a-fable-of-codexes/claude-md"><img src="https://agentmods.dev/badge/instructions/jvogan/a-fable-of-codexes/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 | $0.00388 | $0.00388 |
| Opus 5 | $0.00194 | $0.00194 |
| Sonnet 5 | $0.00078 | $0.00078 |
| Haiku 4.5 | $0.00039 | $0.00039 |
Grade A, and why
a-fable-of-codexes 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 12d 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
Repository guide
Claude Code skills for multi-agent orchestration. Each skill lives at
skills/<name>/SKILL.md with optional scripts/, references/, and
assets/ directories, per the Agent Skills spec.
Working on this repo
- Run
python3 scripts/validate.pyandnpx --yes skills add . --listafter editing any SKILL.md. CI runs both commands. - Keep each SKILL.md under 500 lines. Add
references/files only when content outgrows the main file. - Improve skills by replacing or tightening existing text. Appending grows load cost for every future invocation.
- Keep content machine-agnostic: no personal paths, account names, emails, or references to private tooling.
- Update
examples/when a skill's file formats change; the examples must match what the skill actually produces. - Before committing a mermaid diagram change, render it
(
npx -y @mermaid-js/mermaid-cli -i d.mmd -o d.png) and look at the output. Prefer top-down layouts and collapse parallel siblings into one ×N node — wide horizontal diagrams shrink to illegibility on GitHub, and converging labeled edges overlap.
Writing style
- Direct statements and imperatives. Every sentence carries information.
- Minimize em dashes, especially in the README; prefer colons, parentheses, commas, or separate sentences.
- No slogans or slogan-like phrasing.
- No rhetorical contrast structures ("it's not X, it's Y" / "X, not Y").
- No snark, sales language, defensive language, or obvious caveats.
- State the reason behind a rule when it's not evident; omit it when it is.
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.
- 12d ago First seen · 34 lines · 388 tokens per session scan A 289a2300796b
a-fable-of-codexes CLAUDE.md is an instructions file published in the GitHub repository jvogan/a-fable-of-codexes (49 stars, last pushed 5d ago), licensed MIT. It adds 388 tokens to every session, about $0.0019 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 2026-08-30.
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