#337 added support for context-propagation. To make it more useful, loopback.token should save the access token in the context, so that it can be accessed by other parts of the system. At the moment, the token is stored on the req object only:
See lib/middleware/token.js#54.
Proposed solution:
req.accessToken = token || null;
var ctx = loopback.getCurrentContext();
if (ctx) ctx.accessToken = req.accessToken;