telnetz

Telnet-like command line client for TCP and TLS sockets.

cargo install --path .
telnetz example.com 443 --tls

At a terminal it reads lines interactively (/quit exits). With piped stdin or -c it sends the input and prints the reply until the server closes, -w expires or --expect matches, so it can be used from scripts and AI agents.

telnetz -q --expect 220 -w 5 mail.example.com 25            # exit 0 if banner seen, 3 if not
telnetz -q -w 1 -c PING localhost 6379
printf 'GET / HTTP/1.0\r\n\r\n' | telnetz -q --raw -w 5 example.com 80

Exit codes: 0 ok, 1 connection/IO error, 2 usage error, 3 --expect not seen. See telnetz --help.

Agent skill

skills/telnetz/SKILL.md teaches coding agents to use telnetz. For Claude Code:

cp -r skills/telnetz ~/.claude/skills/