Amazon has announced a new API that is intended to serve as a next-generation Resource in the advancement of everything previously handled by the Amazon Marketplace Web Service (MWS) APITrack this API. The new Amazon Selling Partner API (SP-API) will provide all the legacy functionality offered to developers via MWS in addition to key improvements.
The new SP-API is REST-based and outputs in JSON. Additionally, support for OAuth 2.0 via Login with Amazon is included. Amazon notes that one of the most requested features for the MWS API, an Endpoint for testing, will be included in the SP-API. Going forward developers that already use the MWS API can continue to do so, but Amazon will be only be updating the API for business-critical changes. To access the latest features developers will want to migrate to the SP-API.
Although the new API is not yet generally available, Amazon expects this level of access to be imminent. Make sure to check back as this article will be updated when general availability is announced. For more details, developers can check the documentation for the MWS API.