- fb_graph 1,087 This gem doesn't support FB Graph API v2.0+. Please use fb_graph2 gem instead.
- rack-oauth2 536 OAuth 2.0 Server & Client Library. Both Bearer and MAC token type are supported.
- paypal-express 358 Ruby Gem for PayPal Express Checkout API
- openid_connect 167 OpenID Connect Server & Client Library
- json-jwt 118 JSON Web Token and its family (JSON Web Signature, JSON Web Encryption and JSON Web Key) in Ruby