How does luci handle an incoming ajax request?

Question

Normal ajax request in js before luci on the user side

object.ajax("set_param", {
    noOverlay: 1
}, e, {
    success: function (e, t, a) {
        console.log("Success")
    },
    fail: function (e, t, a) {
        console.log("fail")
    }
})

The request is sent to /cgi-bin/luci/;stok=xxxxxxx/admin/set_param, which, as far as I understand, has a standard form.

#!/usr/bin/lua
require "luci.cacheloader"
require "luci.sgi.cgi"
luci.dispatcher.indexcache = "/tmp/luci-indexcache"
luci.sgi.cgi.run()

The question is where does luci forward and how does it process the ajax request?