cordon

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

npx cordon-cli init

npx cordon-cli start

npm install -g cordon-cli
cordon init

import { defineConfig } from 'cordon-sdk';

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'
  },

  approvals: {
    channel: 'terminal',
    timeoutMs: 60_000,            // auto-deny after 60s if no response
  },
});

// Server-level default
policy: 'approve-writes',

// Per-tool overrides
tools: {
  query:        'allow',    // reads: pass through
  execute:      'approve',  // writes: pause for human approval
  drop_table:   'block',    // catastrophic: always reject
  list_tables:  'log-only', // audit but don't interrupt
},

╔══════════════════════════════════════╗
║  ⚠  APPROVAL REQUIRED               ║
╚══════════════════════════════════════╝
  Server : database
  Tool   : execute_sql
  Args   :
  {
    "query": "DELETE FROM sessions WHERE expires_at < NOW()"
  }

  [A]pprove  [D]eny
  >

{"event":"tool_call_received","callId":"...","serverName":"database","toolName":"execute_sql","timestamp":1773434469641}
{"event":"approval_requested","callId":"...","serverName":"database","toolName":"execute_sql","timestamp":1773434469641}
{"event":"tool_call_approved","callId":"...","serverName":"database","toolName":"execute_sql","timestamp":1773434471203}
{"event":"tool_call_completed","callId":"...","durationMs":34,"isError":false,"timestamp":1773434471237}

policy: 'read-only'  // any tool starting with write/create/update/delete/drop/execute/... is blocked

{
  name: 'database',
  policy: 'approve-writes',
  tools: {
    drop_table:      'block',   // call attempts are rejected
    internal_admin:  'hidden',  // not advertised to the client at all
  },
}

{
  name: 'postgres',
  command: 'npx',
  args: ['-y', '@modelcontextprotocol/server-postgres', process.env.POSTGRES_URL!],
  policy: 'read-only',
  knownTools: ['query', 'list_tables', 'describe_table'],  // your approved surface
  onUnknownTool: 'block',                                  // default when knownTools is set
}

Before:  Claude ──▶ MCP Server A (full access)
         Claude ──▶ MCP Server B (full access)

After:   Claude ──▶ Cordon ──▶ MCP Server A (governed)
                          ──▶ MCP Server B (governed)

{
  name: 'my-server',
  policy: 'approve-writes',   // server default
  tools: {
    safe_read:   'allow',     // override: always allow
    nuke_db:     'block',     // override: always block
  },
}

cd examples/security-showcase
npm install
npm run demo

git clone https://github.com/marras0914/cordon.git
cd cordon
npm install
npm run build
npm run dev