Systems, computer program products and methods implementing protocol-level mapping are described. An identity mapping system intercepts a request from a client device to a distributed computing system. The identity mapping system determines a first protocol of the request. The identity mapping system determines user credentials associated with the request. The identity mapping system authenticates the request based on the user credentials. The identity mapping system determines a service provided by the distributed computing system that the request accesses. The identity mapping system determines service credentials of that service. The identity mapping system translates the first protocol into a second protocol associated with the distributed computing system, including associating the service credentials with the request. The identity mapping system then submits the request to the distributed computing system.