Open Access Status – The open-access status of the publication. This field is filled in automatically when Esploro retrieves information about a publication from Unpaywall by means of the OpenAlex API. This API is invoked when a publication with a DOI is imported into Esploro via Smart Harvesting, Smart Expansion via CSV, or auto-population when the publication is added manually to the database. It may also be invoked for other Smart Expansion and import profiles, as well as SWORD imports, depending on the system settings. By default, this field is blank, indicating that the publication's open-access status was not checked. If a value is selected, it indicates that the status was checked, as follows:

• Green – Articles that are published in toll-access journals, but archived in an open-access archive, or "repository." These repositories may be discipline-specific (like ArXiv) or institutional repositories operated by universities or other institutions. Green articles may be published versions or preprints and can have any license or no license.
• Hybrid – Articles that are free to read because the author or the institution paid for their publication, even though the journal as a whole requires a subscription.
• Gold – Articles that are published in journals that are completely open-access for readers (called "Gold journals" or "OA journals"), but authors or the institution pay for publication.
• Diamond – Articles in fully open-access journals with no article processing charges for either readers or authors.
• Bronze – Articles that are free to read on the publisher's website, without a license that grants any other rights. There may be a delay between publication and availability to read, and articles with this status can be removed unilaterally by the publisher.
• Closed – Articles that are not open access.
• Unknown – This option should be selected by an operator who tried to find the status but did not succeed.

When a status of Diamond, Gold, Hybrid, or Bronze is set for a publication during the import process, a link to the publication, based on its DOI, is included in the metadata of the publication.

When a status of Green is set during the import process, a link may or may not be included in the publication's metadata, depending on the value of the esploro_create_link_for_green_oa parameter. By default, this parameter is set to false, and a link is not created. If the parameter is set to true, a link is created, based on the link provided by OpenAlex. The value of this parameter can be set in the Customer Parameters table (Configuration menu > General > Institution Settings > Institution Settings; see Configuring Institution Settings).