Wrappers provide a ~factory~ method that is responsible for returning a stream when it the wrapper is invoked using: %fopen()%/%include()% %opendir()% %stat()% (only fully implemented in PHP 5). Wrappers can to store a pointer to their own instance specific data in %stream->wrapperthis%. Make sure that you use the %stream_closer% hook to release any resources allocated by your wrapper when the stream is shutdown. You can also override the %fstat()% call for the stream (useful when the actual implementation !== the actual resource).