DataCite gathers metadata for each DOI assigned to an object. The metadata is used for a large index of research data that can be queried directly to find data, obtain stats and explore connections. All the metadata is free to access and review.
To showcase and expose the metadata gathered, DataCite provides an integrated search interface, where it is possible to search, filter and extract all the details from a collection of millions of records.
This interface complements the OAI-PMH service, providing an actionable end-point to query DataCite's metadata collection.