UCWA 1.0 reference
Microsoft Unified Communications Web API 1.0 is a REST API that exposes Lync Server 2013 instant messaging (IM) and presence capabilities.
Last modified: July 23, 2013
Applies to: Lync Server 2013
UCWA 1.0 enables developers to make their enterprise applications and intranets more lively and connected to business contacts.
Key use cases enabled by this API include:
Lighting up Lync presence in business apps and intranets.
Embedding IM experience in enterprise-specific Line of Business apps across platforms/browsers/devices (contextual communications), especially Windows 8, Apple iPad, and others.
Enabling Web Chat - pro-active chat feature for e-commerce site, helpdesk, support, and other scenarios.
UCWA 1.0 is available only to customers who have Lync on-premises.