@hackage wai-session0.3.3

    Provides a generic, cookie-based middleware for sessions that is
    parameterised over the session store, the cookie name, and the
    cookie parameters (such as path, expiry, etc).  Passes a pair of
    functions (lookup key, set key) for the current session through the
    'Vault' in the 'Request'.
    .
    Also provides a simple example session store based on threadsafe
    'IORef's and 'Data.Map'.
    .
    See example/Main.hs in git for example usage.