oob-probe

The oob-probe MCP server exposes TCP and HTTP tooling to assist with testing and research tasks. It provides TCP tools for establishing listener connections, reading logs, and sending data to active connections, as well as HTTP tools to receive requests and inspect full request logs. Ngrok is integrated to expose local listeners publicly, which is useful for testing from external networks or demonstrating SSRF/Reverse-Connection scenarios. Desktop notifications can be enabled to alert you when new connections or requests arrive. To operate, ensure the server binary oob-probe-mcp-server is installed and accessible, then configure ngrok with an authentication token so the public endpoints can be generated.

Available tools:

• TCP: listen_tcp, read_tcp, send_tcp, close_tcp
• HTTP: listen_http, read_http, close_http
• Other: status (to view current server state)

To use the TCP and HTTP listeners, start the MCP server via your MCP host/controller, then invoke listen_tcp or listen_http to begin listening. ngrok tunnels will be created automatically (provided NGROK_AUTHTOKEN is configured or a valid ngrok config file exists). You can read connection logs, inspect HTTP requests in real time, and send data back through active TCP connections as needed for testing. If desktop notifications are enabled, you’ll receive alerts on new connections or requests.

Prerequisites:

• Go installed (to build/install the MCP server): https://golang.org/doc/install
• ngrok installed and configured with an authtoken (or a valid ngrok config file at ~/.config/ngrok/ngrok.yml)

Install the MCP server binary:

# Install the oob-probe MCP server (requires Go environment)
go install github.com/lambdasawa/oob-probe-mcp-server@latest

Configure ngrok authentication (only if you haven't set it up yet):

# Add ngrok authtoken to your config
ngrok config add-authtoken <YOUR_TOKEN>

Optionally, set environment variables for behavior (as needed by MCP config):

# Example: disable desktop notifications by default
export OOB_PROBE_ENABLE_DESKTOP_NOTIFICATION=false

Run the MCP server via your MCP orchestration (as defined in your environment). The MCP config entry should reference the oob-probe-mcp-server binary:

{
  "mcpServers": {
    "oob-probe": {
      "command": "oob-probe-mcp-server",
      "env": {
        "OOB_PROBE_ENABLE_DESKTOP_NOTIFICATION": "false"
      }
    }
  }
}

Verify the server starts and that the ngrok tunnels are created for both TCP and HTTP listeners as configured.

Tips and notes:

• Ensure NGROK_AUTHTOKEN is available or that ngrok.config is properly set up so public endpoints can be created for TCP/HTTP listeners.
• The OOB_PROBE_ENABLE_DESKTOP_NOTIFICATION flag controls desktop alerts; set to true to enable, false to disable.
• The OOB_PROBE_TCP_ADDRESS can be configured to guide the ngrok TCP tunnel address if needed, otherwise it will be determined dynamically.
• This MCP server is intended for research in controlled environments (CTFs, labs); do not expose to untrusted targets.
• If you encounter issues with ngrok tunnels not appearing, check your ngrok config file location and permissions, and verify that the authtoken is valid.