Borrowing it
Nothing to install: this file belongs to jlong/quiddity. 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/jlong/quiddity/main/CLAUDE.mdgit clone --depth 1 https://github.com/jlong/quiddityWrote 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/jlong/quiddity/claude-md)<a href="https://agentmods.dev/instructions/jlong/quiddity/claude-md"><img src="https://agentmods.dev/badge/instructions/jlong/quiddity/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/jlong/quiddity/claude-md"><img src="https://agentmods.dev/badge/instructions/jlong/quiddity/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 | $0.00335 | $0.00335 |
| Opus 5.5 | $0.00134 | $0.00134 |
| Sonnet 5.5 | $0.00067 | $0.00067 |
| Haiku 4.5 | $0.00034 | $0.00034 |
Grade A, and why
quiddity 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 2mo 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
Quiddity
A set of agent skills that generate custom build-loop skills for any project.
Project structure
skills/
q-setup/SKILL.md # Full setup orchestrator
q-scan-project/SKILL.md # Project scan → .quiddity/project.md
q-which-process/SKILL.md # SDLC discovery → .quiddity/process.md
q-which-tools/SKILL.md # Tool discovery → .quiddity/tools.json
q-setup-tools/SKILL.md # CLI/MCP installation guide
q-setup-next-task/SKILL.md # Generates a /next-task skill
q-setup-approve/SKILL.md # Generates an /approve skill
q-setup-new-issue/SKILL.md # Generates a /new-issue skill
Key concepts
- Each skill is a setup wizard — it interviews the user about their systems and generates a custom skill for their project.
- Skills should be conversational. Ask questions, don't assume.
- Generated skills should follow the SKILL.md format (YAML frontmatter + markdown).
- The generated skills should reference the user's actual tools (Linear, GitHub, Jira, etc.) and conventions (branch naming, commit style, PR format).
Writing skills
- Keep SKILL.md files under 500 lines. Move reference material to separate files.
- Use YAML frontmatter for metadata (
name,description,allowed-tools). - Support
$ARGUMENTSfor user input when invoking the generated skills.
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.
- 2mo ago First seen · 33 lines · 335 tokens per session scan A 6fdfa24b2193
quiddity CLAUDE.md is an instructions file published in the GitHub repository jlong/quiddity (5 stars, last pushed 7mo ago), licensed MIT. It adds 335 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.
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