This paper discusses the metadata support in software models based on Representational State Transfer (REST) approach. REST is, without a doubt, the most commonly used software architecture model. REST is simpler and often more attractive to developers, comparing with the Service Oriented Architecture. However, this simplification has led to the fact that the REST architecture skips such an element as a classic model of metadata. Consideration of why the metadata may be needed, and which tools can represent them in the REST architecture is the subject of this article. We specify the possible areas for metadata description in REST. The paper discusses the various existing approaches to the provision of metadata in REST, such as Blueprint API, Apiary, Mashery, WADL, HAL and RSDL. The most prospect areas for metadata in REST are Internet of Things and Machine to Machine applications.