CPQ APIs are based on Salesforce APIs and use the same standards and platforms

Standards

NameReference
Simple Object Access Protocol (SOAP) 1.1http://www.w3.org/TR/2000/NOTE-SOAP-20000508
Web Service Description Language (WSDL) 1.1http://www.w3.org/TR/2001/NOTE-wsdl-20010315
WS-I Basic Profile 1.1http://www.ws-i.org/Profiles/BasicProfile-1.1-2004-08-24.html

Development Platforms

 CPQ SOAP API works with standard SOAP development environments. For a list of compatible development platforms, see Salesforce Developer Force API details.