The AuthorityLabs API is now known as Traject Data’s SEO API. Traject Data’s SEO API makes it easy to track rankings and discover SERP feature opportunities with the most comprehensive set of daily SERP data points. Our SEO API allows you to pull raw search results from our system to yours; queue up a keyword, search engine and location combination, and we’ll return the ~top 100 results in JSON format. With that data you can parse out rankings and data mine the full SERP list returned
See their SEO API documentation here
AuthorityLabs does still have Rank Tracking tool which allows for automated daily local and mobile rank tracking. They support Google & Bing and any country and languages supported by them with tracking search results down to state, city or postcode level.