What is this API?

Microsoft Unified Communications Web API 2.0 is a REST API that exposes Skype for Business Server 2015 instant messaging (IM), presence, and phoneAudio capabilities.

Last modified: April 28, 2015

Applies to: Skype for Business 2015

UCWA 2.0 is a REST API that exposes Skype for Business Server 2015 IM, presence, and phoneAudio (i.e. dialout via PSTN) capabilities. It enables developers to make their enterprise applications and intranets more lively and connected to business contacts.

Key use cases that are enabled by this API include the following.

  • Allow Anonymous Web Chat so that your customers can interact on your website or mobile app with customer service representatives.

  • Light up Skype for Business presence in Line-of-Business Applications and intranets.

  • Embed Cross-Platform communication experiences across browsers and devices.

Although UCWA 2.0 is language-independent, developers can use any programming language from C/C++ to Java, the API is fine-tuned for web developers who are familiar with ordinary web technologies such as HTTP, OAuth, JSON, and JavaScript.

UCWA 2.0 is available only to customers who have Skype for Business on-premises.

Anonymous web chat

An increasing number of online shoppers believe the #1 feature of an e-commerce site is the ability to chat with a rep in real-time. Mobile users also expect support from within apps. The combination of UCWA 2.0 and UCMA 5.0 gives you the tools to delight your website visitors and mobile app users with a seamless customer care experience.

Line-of-Business applications

Want to IM the author of a shared document to ask a question? Or maybe get in touch with the most recent editor of a customer list in your CRM app? UCWA 2.0 enables the seamless embedding of contact card, photos, and more into line-of-business applications, providing a consistent, people-centric experience powered by the same Skype for Business Server already used within the organization.


Need presence on a Surface? Or contact list on Windows Phone? Have a sizable customer base browsing your site with non-Windows machines? As an HTTP-based Web API, UCWA 2.0 can be used from any language and any platform, as long as there is an HTTP stack available. Data is transferred as XML or JSON, both of which are consumable by a wide variety of languages.