The goal of this document is to register in a single source all information required to create configuration files for algorithms executable in CSGrid. From a XML configurator for an algorithm in the repository, the CSGrid client dynamically creates a window for the input of execution parameter to this algorithm. The XML with this configurator is mandatory and must be registered in the algorithms repository according to the different available versions. This document is organized as the following: in section 1, we give a brief introduction to the main concepts of a XML description. In section 2, we present the elements for the definition of algorithms and their input and output parameters. In section 3, we show how to define boolean expressions and some pre-defined functions that can be used on such expressions. In section 4, we present actions that can be applied to the algorithm parameters that change the user interface associated to the algorithm. Finally, in section 5, we present a few examples of algorithm configurations, from a simple algorithm, and showing its construction step by step. Appendix A contains a list of file types that can be used on the XML elements used to define input and output parameters of these types.