Tarantula

Does Tarantula expose an API?
If so is there documentation of what API calls are available?

Client is basically single javascript program accessing server through HTTP get/put/post/delete calls containing json.
So json interface could be used to talk directly to server. Unfortunately this is not documented. If you want to explore this further, you could use e.g. firebug with firefox to see what kind of calls different actions produce. 
On server side you should look first into rails controllers. They define server interface.

reverse-engineered it, and it's not really hard to do it. Tarantula responds with JSON files, which can be easily parsed and read with the 'json' ruby gem.
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