Twitch Api to Upload and Download Videos

API
2

No

The Upload API was removed never made it to helix (is was kraken v4).
And there has never been a download API for anything

if needed add to uservoice citing your use case.

https://twitch.uservoice.com/forums/310213-developers

There is a open UV around clips

https://twitch.uservoice.com/forums/310213-developers/suggestions/39228784-extend-clips-api-to-provide-the-mp4-url-so-editors

Conceptually that would apply to VODs/other video content