Receiving and executing at a server a script provided by a client, e.g., in a service request sent by a web services or other service client and/or consumer, is disclosed. In various embodiments, the script is configured to cause the server to do one or more of the following: pre-process at least a portion of the services request; post-process a response data associated with the services request; and replace an operation comprising the service at least in part with a replacement operation defined or identified at least in part in the script.