API for structured metadata exchange
The National Library is exposing structured metadata in the collective catalogue of the bibnet.lu library network using the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH).
What is OAI-PMH?
The OAI-PMH protocol is a means of exchanging metadata over the Internet between several institutions. The protocol and its specifications are free to use and available on the Open Archives website.
Learn more about OAI-PMH on the official websiteHow does OAI-PMH work?
The basic operations of the OAI-PMH protocol are based on client-to-server communication. The client sends requests to the server via HTTP and the server responds with a stream of data formatted as XML.
BnL’s server endpoint
The BnL is exposing several sets through its OAI-PMH server, two of them being described in detail below.
The address of the OAI server is:
Set: BNL
The BNL set exposes all the bibliographic records and their associated items belonging to the National Library of Luxembourg, including the media library. The metadata is available in 2 formats: MARC21 and Dublin Core.
To list records of the BNL set in XML MARC21 format, send a GET request to:
Set Name
To query this set of data, add the following query string: set=BNL
Format: MARC21
Used in the Integrated Library System of the bibnet.lu network.
To use this format, set the query parameter: metadataPrefix=marc21
Format: Dublin Core
A small set of vocabulary terms that can be used to describe digital resources, as well as physical resources and objects.
To use this format, set the query parameter: metadataPrefix=oai_dc
Set: RFNUM
The RFNUM set contains short bibliographic information in Dublin Core about Public Domain digitised content made available by the BnL through the Réseau Numérique Francophone. The Réseau Numérique Francophone ensures the presence of the Francophone documentary heritage on the Web. This set covers a small subset of the digitised content made available by the BnL on eluxemburgensia.lu. The metadata is only available in Dublin Core.
To list records of the RFNUM set in Dublin Core format, send a GET request to:
Set Name
To query this set of data, add the following query parameter: set=RFNUM
format: Dublin Core
To use this format, set the query parameter: metadataPrefix=oai_dc

Set: LUX-AUT
This dataset contains validated authority records from the bibnet.lu library network’s shared authority file. These records describe persons, being either an author or subject, having a clear link to Luxembourg.
https://catalog.bibnet.lu/OAI?verb=ListRecords&set=LUX-AUT&metadataPrefix=marc21Set Name
To query this set of data, add the following query parameter: set=LUX-AUT
Format: MARC21
Used in the bibnet.lu library network’s shared authority file.
To use this format, set the query parameter: metadataPrefix=marc21
Set: LUX-BIB
This dataset contains bibliographic records linked to validated authority records.. These bibliographic records describe works of persons, having a clear link to Luxembourg, who are either author or subject of these works.
https://catalog.bibnet.lu/OAI?verb=ListRecords&set=LUX-BIB&metadataPrefix=marc21Set Name
To query this set of data, add the following query parameter: set=LUX-BIB
Format: MARC21
Used in the bibnet.lu library network’s shared authority file.
To use this format, set the query parameter: metadataPrefix=marc21

Pagination
The OAI-PMH server supports pagination through a so-called resumption token that is available at the end of the ListRecords element. With this token, you can query the next page as in the following example:
https://catalog.bibnet.lu/OAI?verb=ListRecords&resumptionToken=[[RESUMPTION TOKEN VALUE]]
Note that you should remove the query parameters “metadataPrefix” and “set”.
Metadata Format
The OAI-PMH server provides most data in MARC21 or Dublin Core format. Below, you can find a few links to the official specifications.
MARC 21
MARC21 is a family of standards that are widely used for the representation and exchange of bibliographic, authority, holdings, classification, and community information data in machine-readable form.
MARC21 SpecificationsDublin Core
Dubline Core is a small set of vocabulary terms that can be used to describe digital resources, as well as physical resources and objects.
Dublin Core Specifications