Hi. I use Firefox Nightly and I enabled a secure proxy over TLS using only the built-in features, no addons. My about:config : network.proxy.type = 2 network.proxy.autoconfigurl = data:text/plain,function FindProxyForURL(u,h){return "HTTPS my-secure-proxy:443";} When I open any site for the first time it asks for the proxy credentials as expected: The proxy moz-proxy://my-secure-proxy:443 is requesting a username and a password. After entering the credentials I confirm to save them and as long as the Firefox app is not stopped it works. However, when the app is restarted it asks for the password again with both fields blank and after entering the same credentials it asks me to update the saved credentials. This only happens on Android. Firefox for Windows with the same proxy settings can autocomplete the moz-proxy:// password. I think it has something to do with the OS keyring unable to store the passwords for unknown URI schemas. Is there some workaround for that? https://bugzilla.mozilla.org/show_bug.cgi?id=378637#c68