Google Reader RSS API:

Google Reader RSS API:
* Some docs in rST: https://github.com/arowser/google-reader-api
* Docs by Nick Bradbury: https://ranchero.com/downloads/GoogleReaderAPI-2009.pdf
* FreshRSS basic docs, with some tips: https://freshrss.github.io/FreshRSS/en/developers/06_GoogleReader_API.html
* FeedHQ API docs: https://feedhq.readthedocs.io/en/latest/api/index.html
* Inoreader API docs: https://www.inoreader.com/developers/
* BazQux Reader API docs, with tips on syncing: https://github.com/bazqux/bazqux-api#user-content-the-right-way-to-sync
* Other tips on syncing: https://github.com/FreshRSS/FreshRSS/issues/2566#issuecomment-541317776
Actual code:
* FreshRSS implementation (server-side API layer 2): https://github.com/FreshRSS/FreshRSS/blob/edge/p/api/greader.php
* FreshRSS app for android (client) implementation: https://gitlab.com/christophehenry/freshrss-android/-/blob/develop/app/src/main/java/fr/chenry/android/freshrss/store/api/API.kt