F-DROID: how to retrieve only package names (maybe also versions)

Question

I want to get only package names, from FDroid's repo, once in a while.

What I tried:

• Using the API > gets 1 known package at a time
• download the repo (index-v2.json) > it's 60MB, with TMI (languages, etc)
• search API > always retrieves few / some packages. in efficient.

I'd like to either:

1. get a list of package names
2. search directly for a list of packages (e.g.: https://query?search=org.app1,com.bamba,us.k12.daysa)
3. List item