Interact with the debugger with a custom client #1841

I came across this debugger recently, but I am not able to understand how I could attach a custom client to the debugger.

I have a simple Python script a.py that I want to debug:

import debugpy

debugpy.breakpoint()

a = 1
b = 2
c = a + b
print(c)

At this point, I run the debugger:

python -m debugpy --listen --wait-for-client localhost:5678 a.py

Now, I would like to write a simple client in Python, which connects to the debugger and i) get all the defined variables, ii) continue to the next instruction and iii) repeat until there is code to run.

I couldn't find any documentation on that. Could you please guide me on how I could do this?