You might like to take a look at Irmin [1], which seems like it would make it easier to get what you're after. It's also part of a larger stack that will make distributed programming a lot easier when it lands [2].

[1] http://openmirage.org/blog/introducing-irmin

[2] http://nymote.org/blog/2015/brewing-miso-to-serve-nymote/