ScopeBlind protect-mcp

MCP security gateway. Wraps any MCP server with per-tool policies, Ed25519-signed decision receipts, and human approval gates. Shadow mode logs everything without blocking. Enforce mode applies policy.

protect-mcp — MCP Security Gateway

What This Skill Does

Wraps any MCP server as a transparent stdio proxy with per-tool security policies and cryptographic audit trail. Every tool call decision is logged and optionally Ed25519-signed.

Quick Start

bash

# Shadow mode — log everything, block nothing
npx protect-mcp -- node your-server.js

# Enforce mode — apply per-tool policies
npx protect-mcp --policy policy.json --enforce -- node your-server.js

# Initialize signing (generates Ed25519 keypair)
npx protect-mcp init

Policy Example

json

{
  "tools": {
    "db_write": { "decision": "deny" },
    "file_read": { "decision": "allow", "rateLimit": { "maxCalls": 30, "windowSecs": 60 } },
    "deploy": { "decision": "require_approval" }
  }
}

Pre-built Policy Packs

protect-mcp ships CVE-anchored policy packs:

bash

# List available policies
npx protect-mcp policies

# Apply the Clinejection prevention policy
npx protect-mcp --policy clinejection --enforce -- node your-server.js

Verify Receipts

Receipts are independently verifiable offline — no ScopeBlind dependency:

bash

npx @veritasacta/verify receipt.json
npx @veritasacta/verify --self-test

OWASP MCP Top 10 Coverage

Risk	Control
MCP-01 Rug Pulls	Signed tool manifests; policy pins allowed tools
MCP-03 Tool Poisoning	Per-tool allow/deny/rate-limit policies
MCP-04 Tool Arg Injection	Argument inspection + approval gates
MCP-07 Auth/AuthZ	Trust-tier gating
MCP-08 Logging & Audit	Ed25519-signed receipts — verifiable offline
MCP-09 Excessive Agency	Shadow mode reveals actual tool usage

Links

• npm: https://npmjs.com/package/protect-mcp
• IETF Draft: https://datatracker.ietf.org/doc/draft-farley-acta-signed-receipts/
• Docs: https://scopeblind.com/docs/protect-mcp
• OWASP Mapping: https://scopeblind.com/docs/owasp