Cordon for MCP server

Cordon for MCP

The Security Gateway for MCP Tool Calls

Website • Writeup

Quickstart • Why Cordon • How It Works • Configuration • Roadmap • Contributing

Every company wants to deploy AI agents. No company is willing to give an agent the keys to their database.

Cordon closes the trust gap.

From the maintainer of Agent Toolbelt — 25+ MCP tools, ~1,600 weekly npm downloads.

Demo

https://github.com/user-attachments/assets/153d978f-6303-443a-b49b-b4ec7ebf0452

The Problem

The Model Context Protocol (MCP) has made it trivially easy to give AI agents access to powerful tools — databases, file systems, APIs, cloud infrastructure.

But MCP has no built-in security model. No audit logs. No approval workflows. No rate limits. Today, an AI agent is either off or full admin. There is nothing in between.

This is the single biggest blocker preventing AI agents from reaching production.

The Solution

Cordon is the security gateway that sits between the LLM and your MCP servers.

It acts as a firewall, an auditor, and a remote control — giving you complete visibility and authority over what your AI agents can and cannot do.

┌─────────┐      ┌──────────┐      ┌──────────────┐
│  LLM /  │ ──▶  │  Cordon  │ ──▶  │  MCP Server  │
│  Agent  │ ◀──  │ Gateway  │ ◀──  │  (database,  │
└─────────┘      └──────────┘      │   fs, APIs)  │
                   │               └──────────────┘
                   ├── Policy Engine
                   ├── Audit Logger
                   └── Approval Workflows

No infrastructure changes. No rewrites. One config file.

Quickstart

Step 1 — Initialize

Run this inside your project (where your claudedesktopconfig.json exists):

npx @getcordon/cli init

This reads your existing Claude Desktop MCP config, generates cordon.config.ts, and patches Claude Desktop to route all tool calls through Cordon.

Step 2 — Start

npx @getcordon/cli start

Cordon starts, connects to your MCP servers, and begins intercepting tool calls. Restart Claude Desktop and every tool call now flows through the gateway.

Manual setup

If you prefer to configure manually, install globally and create a config:

npm install -g @getcordon/cli
cordon init

cordon init generates a cordon.config.ts:

import { defineConfig } from '@getcordon/policy';

export default defineConfig({
  servers: [
    {
      name: 'database',
      transport: 'stdio',
      command: 'npx',
      args: ['-y', '@my-org/db-mcp-server'],
      policy: 'read-only',        // Block all write operations
    },
    {
      name: 'github',
      transport: 'stdio',
      command: 'npx',
      args: ['-y', '@modelcontextprotocol/server-github'],
      policy: 'approve-writes',   // Reads pass; writes require approval
      tools: {
        delete_branch: 'block',   // Never, regardless of approval
      },
    },
  ],

  audit: {
    enabled: true,
    output: 'stdout',             // or 'file'
  },

Shortened. The full README is on GitHub.