Borrowing it
Nothing to install: this file belongs to aself101/mcp-secure-server. 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/aself101/mcp-secure-server/main/CLAUDE.mdgit clone --depth 1 https://github.com/aself101/mcp-secure-serverWrote 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/aself101/mcp-secure-server/claude-md)<a href="https://agentmods.dev/instructions/aself101/mcp-secure-server/claude-md"><img src="https://agentmods.dev/badge/instructions/aself101/mcp-secure-server/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/aself101/mcp-secure-server/claude-md"><img src="https://agentmods.dev/badge/instructions/aself101/mcp-secure-server/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 | $0.01014 | $0.01014 |
| Opus 5.5 | $0.00406 | $0.00406 |
| Sonnet 5.5 | $0.00203 | $0.00203 |
| Haiku 4.5 | $0.00101 | $0.00101 |
Grade A, and why
mcp-secure-server 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 13d 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 — 115 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
MCP Security Framework - a secure-by-default MCP server built on the official SDK with 5-layer validation. Provides defense-in-depth against traditional attacks and AI-driven threats.
Commands
# Run all tests
npm test
# Run specific test suites
npm run test:unit
npm run test:integration
npm run test:performance
npm run test:coverage
# Watch mode for development
npm run test:watch
# Typecheck + full suite against the newest MCP SDK 1.x, in a scratch copy (no CI here)
npm run test:sdk-latest
# Type-level guards against built declarations (build first)
npm run check:types
# Cookbook examples: one workspace (`cd cookbook && npm install` once); gates releases via prepublishOnly
npm run test:cookbook
COOKBOOK_LIVE=1 npm run test:cookbook # include tests that call live public APIs
# Start test server (for Claude Desktop integration)
npm run minimal-server
Run a single test file:
npx vitest run test/unit/utils/canonical.test.js
Architecture
Security Layer System
The framework uses a 5-layer validation pipeline:
Request → Layer 1 (Structure) → Layer 2 (Content) → Layer 3 (Behavior) → Layer 4 (Semantics) → Layer 5 (Contextual) → MCP Server
- Layer 1 - Structure (
layer1-structure.ts): JSON-RPC format validation, request size limits, encoding validation - Layer 2 - Content (
layer2-content.ts): Pattern detection for path traversal, command injection, SQL injection, XSS, buffer overflow, CRLF injection - Layer 3 - Behavior (
layer3-behavior.ts): Rate limiting, burst detection, request pattern analysis - Layer 4 - Semantics (
layer4-semantics.ts): Tool contract enforcement, resource access policies, quota management - Layer 5 - Contextual (
layer5-contextual.ts): Custom validators, domain restrictions, OAuth validation, response filtering
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.
- 13d ago Changed · +3 lines · +32 tokens per session 4899f93446cc
- 14d ago Changed · +7 lines · +69 tokens per session 853ea77f447b
- 1mo ago Changed · +2 lines · +25 tokens per session b7755b80e664
- 1mo ago First seen · 103 lines · 888 tokens per session scan A 644f24d85fe3
mcp-secure-server CLAUDE.md is an instructions file published in the GitHub repository aself101/mcp-secure-server (2 stars, last pushed 2d ago), licensed MIT. It adds 1,014 tokens to every session, about $0.0041 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.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
vscode model-prompts.instructions.md
Model-specific prompt authoring and registry guidelines.