This document is a work in progess draft
FxA Web Extension login flow
Your WebExtension must register as a Firefox Accounts relier with a specific WebExtension redirect URL.
Derived encryption keys
Besides just getting the "Bearer Token" (as seen above), there is a plan to provide a way for reliers to fetch keys derived from user's FxA password. To get a derived key the relier can request a `"keys"` scope in the OAuth request.