The latest (tip-of-tree) protocol changes frequently and may break at any time. However it captures the full capabilities of the Protocol, whereas the stable release is a subset. There is no backwards compatibility support guaranteed for the capabilities it introduces.
Latest browser_protocol.json version updated:
Date: Wed Oct 18 21:15:50 2017 -0700
Latest js_protocol.json version updated:
Date: Tue Oct 17 02:15:55 2017 -0700