[shakna]

That particular part is detailed on the knowledge base [0], so... Yes? For just this bit.

But I don't think the full API is documented. There are some attempts to reverse engineer an API from the WebClient [1], but they tend to be... Brittle.

[0] https://protonmail.com/support/knowledge-base/download-publi...

[1] https://github.com/ProtonMail/WebClient