DOM manipulation is sorta working on master, in a limited form. You can follow the instructions in the README, and then you can do:

from browser import document
elem = document.query_selector("css query")
elem.set_attr("attr", "value")
elem.get_attr("attr")

It's in it's early stages now, but we're working on fleshing it out more.

@coolreader18 how could we document this features in a nice way? Maybe we can add some examples on the website for this.

#210 looks like related issue