gecko-dev/testing/web-platform/tests/.well-known/idp-proxy/README.md

Identity Provider Proxy

This directory is used for hosting the mock identity provider proxy script for testing the identity provider feature in WebRTC. [ietf-rtcweb-security-arch] [webrtc-pc]

The script for identity provider proxy must be hosted at /.well-known/idp-proxy instead of the usual /webrtc directory as it follows the well-known URI standard that derives the script URI from a given domain name. [RFC5785]