Instead of updating the same variable in various locations I parse files and extract the bits I need. One bit I am looking for is the cache name in my service-worker.js file. When I'm developing locally, I can easily retrieve the js file in the directory structure. When I deploy my app to GAE, the service worker JS file needs to be declared static and so GAE stashes it away somewhere. Is there a way to get to this file without making a URL call? This is what I currently use and it's all working fine in DEV: <?php function getCacheId() { $cache_id = ""; $c = file_get_contents ( dirname ( __FILE