The API base path is
https://dreamninjas.eu/api/There is no API key required.
The API offers various ways to receive your data for easy parsing. The output choice will go AFTER the API url. Currently supported outputs are: Nothing If you do not specify a format, it will be outputted as a basic string.
JSON Your data will be outputted with a JSON format, and it will usually include status codes.
RTVars Will use the same format that Growtopia uses.
Method: Growtopia Version Free
This will get the currently available version to log into Growtopia. You may not be forced to update to this version, but it is what's currently out.