AG Projects launches OpenXCAP

AG Projects launched OpenXCAP, an open source implementation of an easy extensible, fully featured XCAP server with TLS security and support for multiple realms.

An XCAP server is used in combination with a SIP Presence server that supports PUBLISH/SUBSCRIBE/NOTIFY methods to provide a complete SIP SIMPLE server solution. The XCAP server is used as a policy decision maker to manage subscriptions and notifications of presence information based on end-user preferences.

The XCAP server can also be used to publish to SIP devices information retrieved from external sources and using different APIs acting like a bridge between real-time communications based on SIP protocol and other web technologies like SOAP/XML.

OpenXCAP is an open source, easy extensible, fully featured XCAP server with TLS security and support for multiple realms. The server is written in Python programming language and is based on the following RFC list:

  • The Extensible Markup Language Configuration Access Protocol (RFC 4825)
  • Formats for Representing Resource Lists (RFC 4826)
  • Usage for Manipulating Presence Document Contents (RFC 4827)
  • Presence Authorization Rules draft-ietf-simple-presence-rules-10


Supported XCAP applications:

  • Resource lists. A resource lists application is any application that needs access to a list of resources, identified by a URI, to which operations, such as subscriptions, can be applied.
  • RLS Services. A Resource List Server (RLS) services application is Session Initiation Protocol (SIP) application whereby a server receives SIP SUBSCRIBE requests for resource, and generates subscriptions towards the resource list.
  • PIDF Manipulation. Pidf-manipulation application usage defines how XCAP is used to manipulate the contents of PIDF based presence documents.
  • Presence Rules. A Presence Rules application is an application which uses authorization policies, also known as authorization rules, to specify what presence information can be given to which watchers, and when.

The server supports multiple back-end storage systems and works out of the box with OpenSER Proxy/Registrar/Presence server.


The software is available under a BSD license. You may download the software from

About AG Projects

AG Projects provides since 2002 SIP turnkey scalable solutions for cable companies, Internet service providers and telecom operators.

Having a broad experience in Internet technologies, AG Projects is a skilled vendor able to provide and integrate the key infrastructure elements required for providing real-time communications services like VoIP, IM and Presence.

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