bash-relayd

A minimal TCP server that executes one bash -c "<command>" per client connection.

Usage

Run directly with npx without the install confirmation prompt:

npx --yes bash-relayd

Run on a custom port and host:

npx --yes bash-relayd 5555 127.0.0.1

Run with environment variables:

PORT=5555 HOST=127.0.0.1 npx --yes bash-relayd

Show help:

npx --yes bash-relayd --help

When the server starts, it prints ready-to-run nc commands for each detected local IPv4 address. A typical startup output looks like this:

Listening on 0.0.0.0:4444 - WARNING: unauthenticated shell
Connect using netcat:
  nc 127.0.0.1 4444
  nc 192.168.1.23 4444
  nc 10.0.0.8 4444

After connecting, send a single command followed by a newline:

printf 'uname -a\n' | nc 127.0.0.1 4444

Local Development

npm install
npm run start

Warning

This server is intentionally unauthenticated and allows remote command execution. Do not expose it to untrusted networks.