Various embodiments include at least one of systems, methods, software, and data structures to evaluate function calls within a host, such as a scripting or application programming interface (API) host, prior to execution. Such embodiments may determine if a called function is authorized for execution. When the function is not authorized for execution, the function is not executed. Authorized and unauthorized functions may be set in a representation including one or both of authorized and unauthorized function functions. The representation may be stored external to the host so as to be modifiable.