Is there a defined format of the API key? E.g. the length of the key? I'm writing a library that accesses the API and wish to be able to validate the developer provided key is a real one before trying to access the API.
The key is a 16 digits hexadecimal string in lowercase; don't know if a part contains some sort of checksum, neither no method to check for key validity is available, so may be needed to hit a known query and test for wanted response (but consuming an api call).
A simple regular expression could just validate it, like the following