Does anyone know of an api for on site SEO?

[LesleyPaone]

I have searched for one, but really cannot find one that fits my needs. I am looking at making an on site grader / service that will check pages and point out SEO problems. One that I have found that I like is seorch.eu but they do not have an api. I do not want to reinvent the wheel if I do not have to. Also, the api does not have to be free, or it does not even have to be an api, it can be a self hosted application too.