Status for the API can be found at status.foursquare.com!
Using Foursquare's Places API, you can do just about anything you can do on foursquare.com, while using your programming language of choice. The Foursquare API is a RESTful API based on HTTP requests and JSON responses.
This version of the API, version 2, uses OAuth 2.0. This means that all requests will need to be encrypted and sent via HTTPS. It also means that you need to register your application, even if you aren't allowing users to login.
We highly encourage looking at the endpoints in the Popular Endpoints folder first to evaluate if they suit your needs, before exploring the others.