The API is available at https://api.timewax.com.
The API is realized as an http(s) service which by a POST request sends data to the xml Timewax server. Based on this request XML data is returned. Each service has its own URL and request and response definition. All services are authorized based on a token. The token is obtained using the Timewax credentials. This token is valid for 60 minutes and during that period it can be used for various services.
Requests are subject to rate limiting. For the limits and best practices to handle requests, read this support article.