OAI-PMH API server extension for B2FIND CKAN developed by EUDAT. This extends CKAN to produce OAI-PMH metadata in DataCite format, allowing other systems to harvest metadata from your CKAN instance. Based on ckanext-oaipmh from Kata-CSC. Supports all standard OAI-PMH verbs: GetRecord (fetch single dataset), Identify (server information), ListIdentifiers (dataset identifiers), ListSets (set identifiers), ListRecords, and ListMetadataFormats. Uses a patched version of pyoai with provenance information support.