I want to parse (and alter) all sessions which are stored on the server, if I can do it without using store.
Is there some place where the req.session aggregate is stored? .session is a serverside variable, so it must store all sessions which are active, and should be browsable-alterable.
connect's MemoryStore is not designed for production environments. Here are some alternatives: What is a good session store for a single-host Node.js production app?
Here are all storage options: https://github.com/senchalabs/connect/wiki#session-stores
You could write a proxy to a service like connect-redis to modify sessions as they're stored or retrieved.