on the developer MailingLists . GZIP response encoding is supported by the API to speed up transfer of data. For a reference client implementation in Java , see the applet's source code. Authentication HTTP Simple authentication works for the api now. eg http://foo%40example.com:easypass@www.openstreetmap.org/api/0.3/node/1 will work for user 'foo@example.com' with password 'easypass'.