Developers information: Copac interfaces and database

Copac draws data from multiple sources and interoperates with other services in many ways. Our developers pages give details of how to access Copac through our varied machine-to-machine interfaces, as well as information about our own use of machine-to-machine interfaces to support the service and some of the work that goes into created the consolidated Copac database.

Information about ongoing service developments is provided through the Copac blog.

The Copac team continue to be involved in a range of development activity. You will find details of current development projects on our Innovations page.

Machine-to-machine access to Copac

Although Copac is (mostly) a physical union catalogue, gathering records from multiple sources together in one place, that doesn’t mean it is isolated. We have always emphasised accessibility, in both human and machine terms.

Whilst our Web interface is a popular way of accessing Copac we also have an infrastructure role, offering persistent URLs and a range of machine-to-machine interfaces to support many ways of accessing Copac data through other services. We are aware of Copac use by services through a variety of routes, for example:

  • Libraries accessing Copac through their OpenURL service (eg. University of Durham Library ConneXions);
  • Libraries accessing Copac through their federated search engine (eg. MetaSearch at the University of Gloucestershire) ;
  • Libraries can make Copac accessible as an option through their catalogue, either as a link (eg. MMU Library) or as a search option, to support users who are failing to find materials locally;
  • Other services accessing Copac as a source of location information for materials (eg. History online, Institute of Historical Research);
  • Other services accessing Copac data as a source of additional content, eg: Inform25 are using our Z39.50 interface to bring Copac records into their catalogue as a source of additional record content where appropriate, as well as to access records for materials held by M25 member libraries whose catalogues may not be as readily accessible.
  • Projects sourcing data from Copac to integrate into their developments (eg. musicSpace and MusicNet at Southampton University)

Individuals may also make use of these alternative ways of accessing Copac, for example:

  • Individual users of EndNote and similar reference management software access Copac via Z39.50;
  • Users incorporate Copac plugins into their browser search bar.

If you want more information about any of our machine-to-machine interfaces please get in touch (please state that your enquiry is for the Copac team).

Real-time remote data access through Copac

In addition to the data supplied by our contributors (via sftp) we currently use Z39.50 to draw in content from other services:

  • Cross-searching the English Short Title catalogue at the British Library;
  • Gathering live circulation data, where possible, from contributing libraries;
  • Offering a ‘My Library’ search to let users on non-contributing institutions access their own catalogue alongside Copac.


Given the many, and increasingly varied, data sources used to create Copac the deduplication process is both important and complex.

We deduplicate (almost) all incoming records against those already within the database. The scale of the database means this has to be a completely automated process, so we err on the side of caution – merging records for different documents means one of them is likely to be lost. The result is that duplicates will remain as a result of cataloguing variations and errors. This can be a particular problem with older records where there may be limited content and much greater variation in cataloguing than is the case with more recent records. On the other hand, as we incorporate more data from libraries that are not using the MARC standard then the data may be more varied, introducing further potential for duplicate retention.

The deduplication procedure is not static and as we undertake a major reengineering of the Copac database the whole deduplication process is being redeveloped. There is information about the work happening in this area on our blog: Copac deduplication.