[savoyard]

For command-line use, there is oathtool, which is part of the OATH Toolkit by Simon Josefsson.

https://oath-toolkit.nongnu.org

[tadfisher]

Yes, this is what pass-otp uses under the hood.

[pabs3]

Hi tadfisher! I sent you an email about pass-otp last month, wondering whether you got it or not.