Datumbox offers a Machine Learning platform composed of 14 classifiers and Natural Language processing functions. Functions include sentiment analysis, topic classification, readability assessment, language detection, and much more. The Datumbox API provides developer access using REST-like RPC-style operations over HTTP POST requests. The API accesses all of the platform functions. Responses are JSON formatted. Access requires a user account and API Key. Datumbox API is a web service which allow to use tools from the website, software or mobile application. The API gives access to all of the supported functions of Datumbox service. Datumbox Web Service uses "REST-Like" RPC-style operations over HTTP POST requests with parameters URL encoded into the request and its response is encoded in JSON. It is designed to be easy to use and one can implement it in any model computer language that allows to generat web requests. At the moment Datumbox API currently allows to build applications that make use of Text Analysis and Natural Language Processing techniques such as Online Marketing Tools, SEO Tools, Social Media Monitoring services, Anti-Spam filters and other Text Classification apps. The currently supported API functions are: Sentiment Analysis, Twitter Sentiment Analysis, Subjectivity Analysis, Topic Classification, Spam Detection, Adult Content Detection, Readability Assessment, Language Detection, Commercial Detection, Educational Detection, Gender Detection, Keyword Extraction, Text Extraction and Document Similarity.