Ruby gem providing opaque-token-based authentication for APIs, built to work alongside Devise so an application can keep view-based admin panels while exposing token-auth APIs. Recommended in Rafał Rothenberger's wroclove.rb 2022 talk: great configurability, secure by default, more popular than competing Rails auth-for-API solutions. A release on 10 September moved it from a custom multi-header scheme to the standard Authorization header.