1. A method for providing composite web application comprising the steps of: receiving, at a webshell server, a client request from a client server in the form of an API language request, wherein the client request further comprises a plurality of command line interface (CLI) commands for querying Web services; generating, at a webshell server, an Abstract Syntax Tree (AST) from the client request, wherein the AST comprises syntax nodes and command nodes and at least one command node being associated to at least one request to the Web services; executing, at a webshell server, the Abstract Syntax Tree, wherein each command node execution further comprises: sending to a Web service, a web service request in the form of an application program interface (API) language of the corresponding requested Web service; receiving from the corresponding requested Web service the web data sent back; and storing the web data received as the response of the execution step; combining, at a webshell server, the stored web data into a composite data structure; and sending, at a webshell server, the composite data structure in the form of an API language response to a client computer.