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Protocol for Metadata Harvesting (OAI-PMH)

Introduction

The Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) is a protocol that enables the harvesting of metadata descriptions of records in a repository. The Digital Collections API is an OAI-PMH Data Provider, which means structured metadata is exposed according to the OAI-PMH specification. OAI-PMH is a set of verbs or services that are invoked using the HTTP protocol. The OAI-PMH endpoint is available at https://api.dc.library.northwestern.edu/api/v2/oai.

Please see the OpenAPI specification page for more information about making requests using each OAI-PMH verb, including parameters and examples.

Verbs

All six verbs are supported:

  • GetRecord: Retrieves metadata records from a repository.
  • Identify: Provides information about the repository and its policies.
  • ListIdentifiers: Returns a list of headers for records, without the actual metadata records.
  • ListMetadataFormats: Lists the metadata formats supported by the repository.
  • ListRecords: Returns a list of records, along with metadata records.
  • ListSets: Lists the sets or collections available in the repository.

Metadata Formats

Two metadata formats are supported via the metadataPrefix parameter:

  • oai_dc: Dublin Core, the format required by the OAI-PMH specification.
  • mods: MODS v3.7, which provides richer metadata, including names with authority URIs and roles, typed subjects, rights statement URIs, and links to the item and its thumbnail.

For example: ?verb=GetRecord&identifier=<id>&metadataPrefix=mods