OAI-PMH (https://www.openarchives.org/OAI/openarchivesprotocol.html) provides an application-independent interoperability framework based on metadata harvesting.
The LibraryCloud OAI-PMH Data Provider provides access to metadata about pre-defined sets of items in the Harvard Library collections. OAI "sets" are pre-defined and named as "collections" in the LibraryCloud collection database.
Metadata is provided in the MODS schema (with some LibraryCloud extensions) and Dublin Core.
The service's base address is: https://api.lib.harvard.edu/oai
The ListSets verb will return a list of all harvestable OAI sets defined as LibraryCloud collections.
The ListRecords verb will return full metadata records for a given LibraryCloud collection. Results can be returned as MODS or DC.
The ListIdentifiers verb will return the identifiers of records in a given LibraryCloud collection.
The Identify verb will return information about Harvard's LibraryCloud repository.
The GetRecord verb will return an individual metadata record from the LibraryCloud repository. Required arguments specify the identifier of the item to be requested and the format of the metadata that should be included in the record.
The ListMetadataFormats verb will return the metadata formats available from the LibraryCloud repository. An optional argument restricts the request to the formats available for a specific item.
The OAI requests for ListSets, ListRecords, and ListIdentifiers retrieve 10 results at a time, so the repeated use of a resumptionToken in the request URL is needed to retrieve the full amount of data.
For a ListRecords request in the Scarlet collection -- https://api.lib.harvard.edu/oai/?verb=ListRecords&metadataPrefix=mods&set=scarlet -- this is how to use the resumption token to retrieve additional data beyond the first 10 items: