I think you might get more interest if the front page is improved; it’s a bit hard to see what it does.
I see a screenshot of an API request using curl. However, it’s not clear what the response is. There is a hard-to-read comment in grey on black, but I’m not sure what exactly is generated? Is it the description of the adder function?
It would be good to have a page of API examples that you can read without signing up.