Abstract: A method includes client application code which is deployed to a client device having a generic client library. The client application code has code for accessing a web service of a web application via a web application programming interface (API) and running the client application code on the client device to: communicate a web service operation call to the web API and receive a web service operation response from the web API via the interface. The generic client library has code defining a first proxy class within which is defined a generic operation method, configured such that, responsive to receipt of an operation name parameter corresponding to a web service operation performed by the web application from a function caller of the client application code, the operation method returns an operation function object providing the interface between the client application code and the web API.