How to show the directory structure from git in the browser and conveniently tag files?

Question

git

We need open source solutions DAM (digital asset management), which allows you to show the directory structure with resources from the git (mostly pictures) through the web interface and conveniently tag and / or organize it into virtual containers. You also need an API to get this data in json format.
As an example of the most primitive option: thunderbit.github.io/thunderbit
Please share your ideas, thanks!