Skip to main content
OCLC Support

Search collection using WMS Z39.50

Leverage the WMS Z39.50 service to allow consortial borrowing or other third-party clients that rely on the legacy Z39.50 protocol to search your holdings and retrieve real-time item availability information for your physical collection.


 Note: WMS will continue to support our modern, standards-based APIs for searching your collection and retrieving real-time availability information. Refer to the OCLC Developer Network or contact OCLC Support for assistance.

WMS's implementation complies with the standard Z39.50 Information Retrieval Protocol (ANSI/NISO Z39.50/ISO 23950). To learn more about Z39.50, refer to the resources provided by the Library of Congress.

No configuration is required to use the WMS Z39.50 Service. However, any service that wishes to connect via Z39.50 will need to request a web service key (WSKey) from OCLC.

WMS Z39.50 will provide access to your library's holdings by searching global bibliographic data in WorldCat.

  • At this time, your library's local bibliographic data and temporary items cannot be searched via Z39.50.
  • You may request up to 100 results per search with up to 20 results per page. Your institution will be limited to ten requests in any five-second period.
  • Results will always be sorted by relevance.

 Caution: The WMS Z39.50 Service supports consortial borrowing, interlibrary loans, acquisition/selection, and some collection assessment workflows. This service is not intended to support cataloging activities, loading or refreshing records stored in a union catalog, or any process that needs to retrieve large record sets.

Request a web service key (WSKey)

Any service that wishes to connect via Z39.50 will need to request a web service key (WSKey) from OCLC and agree to the terms and conditions for using this service. When requesting the WSKey, select the Z39.50 For WMS Libraries checkbox in the Please select at least one Service table.

The key and secret will be used to authorize the client and open a connection to the service.

Each key will provide access to only one WMS institution. If you would like to search holdings for multiple WMS libraries, then a key must be requested and maintained for each WMS institution.

Direct your query to database Z39WMS~ followed by your institution's WorldCat Registry ID. For example, to search the holdings of an institution with WorldCat Registry ID 12345, you should use database Z39WMS~12345. Regardless of your WMS data center, Z39.50 queries should be directed to:

  • Host:
  • Port: 210

Record format options for search results

WMS Z39.50 supports the following options for how records will be formatted in the response provided by WMS:

  • MARC21
  • OPAC

In Z39.50, these formats are options for presenting records to the client.

Regardless of the format specified by the client, WMS will provide the following metadata for each search result:

  • Bibliographic data from the global WorldCat record.
  • Local holdings data from your library's WorldCat local holdings records (LHRs).
  • Real-time availability information from WorldShare Circulation for barcoded materials.

     Note: Item status is provided as it appears in the WMS Availability API. It is not translated per the OPAC Status Grid. For example, if an item is in Available status in WorldShare Circulation, then Z39.50 will always provide availableNow value=1 even if the item's shelving location is treated as unavailable in WorldCat Discovery.

WMS Z39.50 will not provide local bibliographic data or links to electronic resources from the WorldCat knowledge base.

Simple searches

Twelve simple searches are currently supported for the WMS Z39.50 Service. A simple search only requires the client to specify the index (use attribute) and term to be searched. Simple searches are easy for clients to configure and execute. A client may combine multiple simple and/or complex searches to form an expert query.

Click here to see more details about simple searches
Search Type Z39.50 Use Attribute Value
Author 1003
Date of Publication 31
Format / Type of Material 1031
Key Title 33
Keyword 1016
Language of Material 54
OCLC Number 1211
Standard Identifier 1007
Subject 21
Title 4

Complex searches defined by the Bath Profile 2.0

Fourteen complex searches are currently supported for the WMS Z39.50 Service. Complex, precise searches are sometimes needed to help a client find exactly what you need or expect. These complex searches follow the guidelines set by the Bath Profile on how to form and interpret queries using bib-1 attribute types and values. To learn more about bib-1 attributes, refer to the documentation provided by the Library of Congress.

The Bath Profile was developed in the late 1990s to further standardize bibliographic search and retrieval behaviors via Z39.50. 

The following complex searches may be combined to form expert queries as well.

Click here to see more details about complex searches
Search Type Bath Conformance Level & ID from Functional Area A Use Attribute Relation Attribute Position Attribute Structure Attribute Truncation Attribute Completeness Attribute
Author - Keyword Level 0 - 5.A.0.1 1003 3 3 2 100 1
Title - Keyword Level 0 - 5.A.0.1 4 3 3 2 100 1
Subject - Keyword Level 0 - 5.A.0.3 21 3 3 2 100 1
Any Search - Keyword Level 0 - 5.A.0.4 1016 3 3 2 100 1
Author - Exact Match Level 1 - 5.A.1.2 1003 3 1 1 100 3
Title - Exact Match Level 1 - 5.A.1.6 4 3 1 1 100 3
Subject - Exact Match Level 1 - 5.A.1.10 21 3 1 1 100 3
Standard Identifier Level 1 - 5.A.14 107 3 1 1 100 1
Date of Publication Level 1 - 5.A.15 31 1, 2, 3, 4, or 5 1 4 100 1
Key Title - Keyword Level 2 - 5.A.2.1 33 3 1 2 100 1
Key Title - Exact Level 2 - 5.A.2.3 33 3 1 1 100 3
Format / Type of Material Level 2 - 5.A.2.6 & 5.A.2.7 1031 3 3 1 or 2 100 1
Language Search - Keyword Level 2 - 5.A.2.7 54 3 3 2 100 1
Date of Publication Range Level 2 - 5.A.2.8 31 104 3 4 100 1