TOTP (like in Google Authenticator android app) using https://github.com/pyauth/pyotp, and (optional) gpg to secure the secret

totpauth.sh

#!/bin/bash

# How to use
# 1. Clone https://github.com/pyauth/pyotp.git
# 2. Put this file in the repo root dir
# 3. GPG-encrypt your TOTP key/seed (without newline), place it in secret.asc in the repo root dir
# 4. Run this file

cd `dirname $0`/src
watch gpg -dq ../secret.asc \| python3 -c \''import pyotp;print(pyotp.TOTP(input()).now(),end="")'\'

x-totpauth-insecure-version.sh

#!/bin/bash

# How to use
# 1. Clone https://github.com/pyauth/pyotp.git
# 2. Put this file in the repo root dir
# 3. Replace __YOUR_KEY_HERE__ below with your TOTP key/seed
# 4. Run this file

cd `dirname $0`/src
watch python3 -c \''import pyotp;print(pyotp.TOTP("__YOUR_KEY_HERE__").now(),end="")'\'