Today I created a Drafts Action to send a list of highlights to Readwise using the API. Was pretty simple and works really nice for my needs! You can check it out here if you’re interested: Send to Readwise | Drafts Directory
Very cool! Took me a minute to figure out the format, but found it in the script as you pointed out in the description. Thanks for sharing 
@evanfuchs Hope it’s helpful!
I forgot to note that right now it only works for books, but could easily be extended to other source types.