Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add instructions/badchars/mcp-security-scanner/claude-mdgit clone --depth 1 https://github.com/badchars/mcp-security-scannerWrote 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/badchars/mcp-security-scanner/claude-md)<a href="https://agentmods.dev/instructions/badchars/mcp-security-scanner/claude-md"><img src="https://agentmods.dev/badge/instructions/badchars/mcp-security-scanner/claude-md.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 | $0.00442 | $0.00442 |
| Opus 5 | $0.00221 | $0.00221 |
| Sonnet 5 | $0.00088 | $0.00088 |
| Haiku 4.5 | $0.00044 | $0.00044 |
Grade A, and why
mcp-security-scanner 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 5d 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
mcp-security-scanner — MCP Security Scanner
Overview
43-tool MCP server + CLI for scanning MCP servers and their source code for security vulnerabilities. Runtime inspection, AST-based static analysis, config audit, dependency analysis. OWASP MCP Top 10 compliance mapping. 100% local, zero external API calls.
Architecture
- Runtime: Bun 1.3.9+ (dev), Node.js (publish)
- Dependencies: @modelcontextprotocol/sdk, ts-morph, zod (3 runtime deps only)
- Transport: stdio only
- Pattern: Each category in own directory under src/, tools registered in src/protocol/tools.ts
Key Rules
- TypeScript strict mode, English code/comments
- Every tool schema field must have
.describe() - Import paths use
.jsextension (ESM) - Zero external API calls — all analysis runs locally
- Finding IDs follow pattern: CATEGORY-CHECK-NNN (e.g. SAST-CMD-001, RT-POISON-003)
Tool Categories (43 tools)
rt_— Runtime Inspection (11 tools): connect to live MCP servers, inspect capabilitiessast_— Static Analysis (12 tools): AST-based code scanning via ts-morphcfg_— Config Audit (7 tools): parse and audit MCP client configsdep_— Dependency Analysis (7 tools): lockfile parsing, typosquat detectionreport_— Reports (4 tools): markdown, SARIF, JSON, full audit orchestratorscanner_— Meta (2 tools): check listing, OWASP mapping
Commands
bun install # Install deps
bun run dev # Dev mode (watch)
bun run build # Build for npm
bun run src/index.ts --help # CLI help
bun run src/index.ts --list # List all tools
bun run src/index.ts --tool <name> '<json>' # Run single tool
bun run src/index.ts --full-audit ./path # Full security audit
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.
- 5d ago First seen · 39 lines · 442 tokens per session scan A cb2d6552a141
mcp-security-scanner CLAUDE.md is an instructions file published in the GitHub repository badchars/mcp-security-scanner (5 stars, last pushed 3d ago), licensed MIT. It adds 442 tokens to every session, about $0.0022 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.
Other instructions, from other repositories
trustmcp CLAUDE.md
Instructions for v0idw4lker/trustmcp, a project described as: Free, open-source security scanner for MCP servers, static analysis, live dynamic probing, auth posture detection, and SARIF/JSON reporting with A-F scoring mapped to OWASP MCP Top 10.
aigis CLAUDE.md
Claude Code instructions for killertcell428/aigis, covering aigis — project guidelines, zenn記事管理(zenn cli + github連携), ディレクトリ構成, 記事の作成 and プレビュー.
assay CLAUDE.md
Claude Code instructions for Rul1an/assay, covering assay - ai agent context, what is assay?, workspace structure, key commands and cli entry points.
Agent-Security-Regression-Harness AGENTS.md
Instructions for OWASP/Agent-Security-Regression-Harness, covering ai agent guide: owasp agent security regression harness, project overview, architecture, contribution workflow and what needs doing.
calc-mcp CLAUDE.md
Claude Code instructions for coo-quack/calc-mcp, covering project rules, tech stack, commands, project structure and tool architecture.
rosetta CLAUDE.md
Instructions for tikoci/rosetta, covering rosetta, project documentation, where does this go?, instruction routing and fast pointers.