As far as I have been able to determine, there is not a way to do authentication for the mitmweb web interface. I found some some reference that this had been done in the past and then removed (in 3.0.3?). Is there a possibility this could come back? One application is for testing in a moderately secure environment that needs to use the web interface on a public-facing internet. The administrators would very much like to secure the web interface, almost to the point of telling us not to use the tool. Thanks for your consideration.