The Connector Framework, or CF for short, is a system for creating, maintaining and invoking connectors – that is, network gateways which accept search requests in a standard protocol such as ANSI/NISO Z39.50 or the Library of Congress's SRU (Search/Retrieve via URL), and fulfil those requests by querying a back-end service which does not itself support the standard protocol. Standard protocols for searching are widely used by tools such as Index Data's metasearching middleware Pazpar2. The use of connectors extends the range of resources that such tools can access.
CF version 2.3 and later also offers a Web service which allows all tasks to be executed via HTTP. See cf_webservice(8) for more information.