Borrowing it
Nothing to install: this file belongs to donnfelker/donnfelker-plugin-marketplace. 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/donnfelker/donnfelker-plugin-marketplace/main/CLAUDE.mdgit clone --depth 1 https://github.com/donnfelker/donnfelker-plugin-marketplaceWrote 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/donnfelker/donnfelker-plugin-marketplace/claude-md)<a href="https://agentmods.dev/instructions/donnfelker/donnfelker-plugin-marketplace/claude-md"><img src="https://agentmods.dev/badge/instructions/donnfelker/donnfelker-plugin-marketplace/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/donnfelker/donnfelker-plugin-marketplace/claude-md"><img src="https://agentmods.dev/badge/instructions/donnfelker/donnfelker-plugin-marketplace/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 | $0.00528 | $0.00528 |
| Opus 5 | $0.00264 | $0.00264 |
| Sonnet 5 | $0.00106 | $0.00106 |
| Haiku 4.5 | $0.00053 | $0.00053 |
Grade A, and why
donnfelker-plugin-marketplace 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 11d 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
@AGENTS.md
Generalization rule for plugins and skills
When authoring or editing any content under plugins/ — SKILL.md, reference files, command files, agent prompts, hooks, scripts, or assets — never include specifics from the source material that produced the lesson. The repo is published to other operators; their context will not match yours.
Strip or generalize:
- Workspace, team, customer, or company names (e.g., real team short codes, workspace slugs, org names). Use placeholder tokens like
TEAM,ACME,<workspace>,<team>,<TEAM>-<N>instead. - Real project, product, feature, or codename references (e.g., internal project names, product codenames, branded initiatives). Either drop them or replace with a generic phrasing ("a multi-phase plan", "the project").
- Specific issue/ticket/PR identifiers and URLs (e.g.,
TRX-5,LIN-1234,https://linear.app/acme/issue/…). Replace with shape-only examples (<TEAM>-<N>,https://linear.app/<workspace>/issue/<TEAM>-<N>). - UUIDs, API keys, account IDs, session IDs, file paths under a real user home, internal hostnames. Use
<uuid>,/Users/<user>/...,<session>, etc. - Exact counts that only happened once (e.g., "the import created 56 issues across 7 phases"). Generalize to shape ("a typical multi-phase plan produces a project plus a few dozen task sub-issues") unless the exact count itself is the lesson.
- Label names, status names, or workflow values from a specific team that aren't part of the platform's defaults. Either name the platform default or describe the shape ("a label scoped to the import").
Keep:
- Platform-default vocabulary (e.g., Linear's default workflow states
Backlog,Todo,In Progress,In Review,Done,Canceled,Duplicate— these come from Linear, not the source import). - Tool names, parameter names, and exact error strings — these are the platform's, not the operator's.
- Generic example identifiers using placeholder tokens (
TEAM-5,ACME-6).
The test before saving: would a reader at a different company learn the same lesson from this content, or would they have to mentally substitute every example? If the latter, generalize.
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.
- 11d ago First seen · 23 lines · 528 tokens per session scan A 2ef7c1919d15
donnfelker-plugin-marketplace CLAUDE.md is an instructions file published in the GitHub repository donnfelker/donnfelker-plugin-marketplace (4 stars, last pushed 2mo ago), licensed MIT. It adds 528 tokens to every session, about $0.0026 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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