@getcordon/cli

@getcordon/cli

The command-line interface for Cordon for MCP, the security gateway for MCP tool calls.

Install

npm install -g @getcordon/cli

Quickstart

cordon init      # reads your Claude Desktop config, generates cordon.config.ts,
                 # patches Claude Desktop to route tool calls through Cordon
cordon start     # launches the gateway

Restart Claude Desktop after cordon init. Every MCP tool call now flows through Cordon.

Commands

Command	What it does
cordon init	Reads your Claude Desktop config, generates cordon.config.ts, patches the client to route through Cordon (backs up the original). Offers to sign you in inline.
cordon start	Launches the gateway. --port <n> serves HTTP/Streamable HTTP instead of stdio (default port 7777, path /mcp).
cordon login	Browser-based GitHub OAuth. Creates an API key and writes ~/.cordon/auth.json, which enables the hosted dashboard, Slack approvals, and replay.
cordon logout	Removes the stored credentials.
cordon replay <callId>	Re-runs a tool call that was approved after it timed out. See below.

cordon replay

An approval that nobody answers in time is denied, and the agent moves on — but the decision itself isn't lost. If someone approves the card late, the call becomes replayable:

cordon replay 7f3c1a2e-...        # prompts for confirmation
cordon replay 7f3c1a2e-... --yes  # skip the prompt

It fetches the approval record, calls the tool on the upstream server, logs the outcome to your audit stream with reason replay of late-approved call, and clears the entry from the recoverable list. The dashboard shows the exact command for any recoverable call under What changed → Timed-out approvals.

Two things worth knowing before you rely on it:

• It replays the tool call, not the agent's session. The agent that made the original request is long gone. You get the side effect the call would have had, not a resumed conversation.
• Only a call approved after timing out can be replayed. Anything else — pending, denied, or normally approved — is refused, because replaying a call that already ran would double-execute it and replaying a denied one would run something nobody authorized. Non-idempotent tools still have real side effects on replay, which is why it confirms first.

Requires cordon login, and the upstream server must still be present in your cordon.config.ts.

What it does

• Scans claude_desktop_config.json and generates a starter cordon.config.ts
• Patches your MCP client config to route through Cordon (opt-in, backed up)
• Runs the gateway as an MCP server that aggregates your existing upstream servers
• Enforces per-tool policies (allow, block, approve, read-only, log-only, hidden, sql-read-only, sql-approve-writes)
• Supports closed-world tool catalogs via knownTools so new upstream tools don't silently become callable
• SQL-aware policies parse the statement in tool-call args and decide based on type (SELECT vs DML vs DDL)
• Surfaces approval prompts in the terminal, or Slack via the hosted dashboard
• Retains approvals that timed out, so a late decision can still be acted on (cordon replay)

Config example

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

export default defineConfig({
  servers: [
    {
      name: 'database',
      transport: 'stdio',
      command: 'npx',
      args: ['-y', '@modelcontextprotocol/server-postgres', process.env.POSTGRES_URL!],
      policy: 'read-only',
      // Optional: declare the exact tool surface you expect. New tools in
      // future upstream releases get blocked until you add them here.
      knownTools: ['query', 'list_tables', 'describe_table'],
    },
  ],
  audit: { enabled: true, output: 'file' },
  approvals: { channel: 'terminal', timeoutMs: 60_000 },
});

Full documentation

Complete policy reference, approval channels, audit outputs, and architecture overview: https://github.com/marras0914/cordon

Writeup with real-world examples: https://dev.to/marras0914/mcp-has-no-security-model-heres-how-to-fix-it-in-2-minutes-5f7o

License

MIT