Metadata Plus gives you enhanced access to all our supported APIs, guarantees service levels and support, and additional features such as snapshots and priority service/rate limits. To use Metadata Plus, an optional paid-for service, you do not need to be a member. In addition to enhanced access to all our supported APIs (OAI-PMH and REST APIs) and metadata in XML and JSON, Metadata Plus provides you with: a service level agreement guaranteeing you extra service and support, giving you a consistent and predictable experience additional features such as snapshots and priority service/rate limits. Metadata Plus users may use either or both of the included API interfaces: