Heroku announced its pending sunset of the Heroku Platform API (v2). Heroku originally released v3 two years ago, and most users have already migrated to v3. v2 remains an unofficial, non-supported version. Accordingly, v2 is officially deprecated and will sunset on April 15, 2017.
In addition to the upcoming sunset, Heroku will sunset support of auth in query string before April 15th. That change will be recorded alongside all updates in the Changelog. Given the imminent changes, Heroku encourages developers to migrate to v3 as soon as possible and offers technical support to those who need assistance. Simply login to your account for help migrating.
Heroku has focused all its recent attention on v3 development and will continue to do so as v2 sunsets. v3 allows users to automate and instrument Heroku in a manner that streamlines product development. For a complete guide to the benefits and operation of v3, visit the Platform API Reference. The Platform API enables developers to extend and combine Heroku with third party services. For those new to Heroku, check out the Getting Started with the Platform API.