The Stripe Ruby Library by Stripe is a REST resource. The library API is designed for predictable, resource-oriented URLs and HTTP response codes to indicate API errors. Further, it aims to support the built-in HTTP features, like HTTP authentication and HTTP verbs with off-the-shelf HTTP clients, and the support cross-origin resource sharing to allow interaction with the API from a client-side web application. The returns are in JSON, including errors.
Rebelmail publicly launched its interactive email API. After successful private integrations with ESPs like Mailjet, SendGrid, and others; Rebelmail is ready for third party integrations across the board. Through the API, users can build, send, and track interactive emails directly within an app.
Shoutlet, enterprise social marketing platform, has added a contact form API to its plethora of social media services. The API allows developers to gather contact information (e.g. data from an online sign up form) and automatically update the Shoutlet contact database with the pertinent information.