This is a super basic pomodoro CLI. It sends desktop notification using notify-send, and it has fairly simply integration with i3blocks (using pomo_state.py).
Just run ./pomo_runner.py (or python3 pomo_runner.py).
There's an install script that creates symlinks for the start_pomo and cancel_pomo executables, in /usr/bin. Simply run chmod +x install.sh && ./install.sh, and you should be good to go.
Add the following to your .i3blocks.conf:
[pomo]
command=/path/to/pomodoro/pomo_state.py
interval=1
Remember to make pomo_state.py executable with chmod +x pomo_state.py.
Once you've added it to i3blocks, just run pomo_runner.py for the CLI, and the current time remaining will be shown in your progress bar.