Can I add issues to github from the command line?

With Github's new official CLI (command line interface):

gh issue create --title "How to create an issue?" --body "I need a github CLI"

See additional details and options and installation instructions.

There's a ghi gem that you can use to manage issues.

The most commonly used ghi commands are:
   list        List your issues (or a repository's)
   show        Show an issue's details
   open        Open (or reopen) an issue
   close       Close an issue
   edit        Modify an existing issue
   comment     Leave a comment on an issue
   label       Create, list, modify, or delete labels
   assign      Assign an issue to yourself (or someone else)
   milestone   Manage project milestones

You could check out this cli for the Github issues API. Note this is specific to Github Issues only.

Hope this helps.

[edit] The original answer mentioned this application which doesn't function anymore and recommends ghi.