A device secures open authorization (OAuth) resources according to systems described herein. In some instances, a resource server is configured for receiving a request for authorization from a client device. The request, for authorization to use a requested resource, may include a token having at least one claim. The resource server may interpret data of the token according to a domain specific language. The interpreting may obtain at least one rule associated with the at least one claim from among a range of resource access control rules. The rule may be compared against a resource request and operation. Based on the comparison, the request may be allowed or rejected. In one example, interpretation of the token may decode resources including quantities and combinations of uniform resource identifiers (URIs) claimed by the token using a domain specific language defined by a context-free grammar.