>>> I’m thinking of rather not exposing multisession.el directly,
>>> but instead use it as a backend for store.el.
>> 
>> What is store.el?  Could you show us its interface specs?
>> Is it written, or is it a proposal?
> 
> still a proposal, of a common abstraction over persistent key-value 
> stores, that would have sqlite among backends, but also lisp-implemented 
> stores such as the “one-file-per-value in a directory” persist.el currently 
> use (most efficient on btree fs like btrfs or zfs), and a logging delta 
> store qiantan hong implemented initially on a scratch by reaction to 
> sqlite suggestion.
It is now written BTW. I’ve finished the work of extracting
key value store part from resist!.el. I haven’t start extracting
persistent variable part as I haven’t hear back about persist.el
namespace availability yet.

I’ve already included the above mentioned two backends.
Lars’ sqlite3 implementation could be included as the third
with slight modification.

Code is hosted at https://code.librehq.com/qhong/store.el/
For people that don’t want to follow link, I also attach the
current revision below