The present invention is directed at a reflection-based shell that provides reflection-based processing of input parameters for a command. The reflection-based processing includes parsing, data generation, data validation, object encoding, object processing, documentation, and the like. The reflection-based shell provides a mechanism for specifying a grammar for the input parameters using a class. The method includes receiving a parsable stream that includes a command and at least one parameter. Retrieving definitional information that describes an expected parameter for the command. Using the definitional information to create an object for storing the at least one parameter in a format in accordance with the description of the expected parameters. Passing the object to the command. The object not having a method invocable by the command.