An API key is a string that uniquely identifies a client (like the web client vs the iPhone client) to the server.
Client keys allow us to track which clients are being used for what purpose. For example, if we find that people are using their own bots for a certain type of function, we may decide that just needs to become a game feature. Or if we find that the iPhone client is being used more than the web client, then maybe there's something wrong with the web client, or maybe it's time to build an Android client.
They are only used on methods that create a session, such as login and found in Empire.
You can register for an API key by going to https://servername.lacunaexpanse.com/apikey. That's the API Key Console.
Yes.
Since API keys are specific to a specific server how am I supposed to write a client for multiple servers?
Register a key on each server, and then depending on which server a user selects in your app, use the right key for that server.
No they are not. The API keys are only used to track which client is using which features of the API. They are used solely to help us determine strengths and weaknesses in our own client offerings, and since we're opening this up to you, it can help you in the same way.
It's true that your API key is public. That's why when we generate your public API key, we also generate a private one that you should keep secret and secure. Then you'll be the only one who can see your usage stats.
The public key is used in your application when making calls to the server.
The private key is used when you want to check the stats of your public key on the API Key Console.
We weren't sure how many people would actually want to use this feature so we haven't put a lot of time into it. We're tracking a lot of things, we're just not displaying much. If there's something you want to see, talk about that in the Developers Forum (http://community.lacunaexpanse.com/forums/developers). Don't bother asking for specific user information. That would be a privacy violation, and we're not about to violate our user's privacy.
There is an anonymous public key just for this purpose. Just pass the word anonymous where you would normally put an API key. Be warned though, this is truely anonymous, so if you change your mind later all that trend data will be lost.