Borrowing it
Nothing to install: this file belongs to wyattjoh/jsr-mcp. 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/wyattjoh/jsr-mcp/main/CLAUDE.mdgit clone --depth 1 https://github.com/wyattjoh/jsr-mcpWrote 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/wyattjoh/jsr-mcp/claude-md)<a href="https://agentmods.dev/instructions/wyattjoh/jsr-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/wyattjoh/jsr-mcp/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/wyattjoh/jsr-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/wyattjoh/jsr-mcp/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 | $0.01113 | $0.01113 |
| Opus 5 | $0.00557 | $0.00557 |
| Sonnet 5 | $0.00223 | $0.00223 |
| Haiku 4.5 | $0.00111 | $0.00111 |
Grade A, and why
jsr-mcp 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 9d 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 — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
Project Overview
This is a Deno workspace containing two packages:
- @wyattjoh/jsr - A TypeScript client library for the JSR (JavaScript Registry) API
- @wyattjoh/jsr-mcp - A Model Context Protocol (MCP) server that exposes JSR functionality to AI assistants
The workspace structure follows Deno best practices with separate packages that can be independently published to JSR.
Workspace Structure
/
├── deno.json # Workspace configuration
├── packages/
│ ├── jsr/ # JSR client library package
│ │ ├── deno.json # Package configuration
│ │ ├── mod.ts # Main exports
│ │ ├── src/
│ │ │ ├── client.ts # JSR API client implementation
│ │ │ └── types.ts # TypeScript types and Zod schemas
│ │ └── tests/
│ │ └── client.test.ts
│ └── jsr-mcp/ # MCP server package
│ ├── deno.json # Package configuration
│ ├── mod.ts # Main entry point
│ ├── src/
│ │ └── index.ts # MCP server implementation with inline tool definitions
│ └── tests/
│ └── server.test.ts
Development Commands
Workspace-level commands (run from root):
- Format all code:
deno fmt - Lint all code:
deno lint - Type check all code:
deno check packages/jsr/mod.ts packages/jsr-mcp/mod.ts - Run all tests:
deno test --allow-net packages/ - Run a single test file:
deno test --allow-net packages/jsr/tests/client.test.ts - Run development server:
deno run --allow-read --allow-write --allow-env --allow-run --allow-net --watch packages/jsr-mcp/mod.ts - Run production server:
deno run --allow-read --allow-write --allow-env --allow-run --allow-net packages/jsr-mcp/mod.ts - Build MCP server binary:
cd packages/jsr-mcp && deno compile --allow-read --allow-write --allow-env --allow-run --allow-net --output=jsr-mcp mod.ts
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.
- 9d ago First seen · 98 lines · 1,113 tokens per session scan A ad469a450331
jsr-mcp CLAUDE.md is an instructions file published in the GitHub repository wyattjoh/jsr-mcp (4 stars, last pushed 8mo ago), licensed MIT. It adds 1,113 tokens to every session, about $0.0056 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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