If you have your game on the Clay.io platform, the API is optional. We think it's a great set of tools that will enhance your game, but if you disagree, we won't be hurt.
The API is however required if you are going to charge for your game. You'll need to have some way of determining if a player has purchased the game and is able to play it, and that's through the API.
A common question developers ask us is whether the API works only on Clay.io. The answer is your game will work anywhere, whether it's your own site, the Chrome Web Store, etc.
Many tools are provided like leaderboards, achievements, data storage, payment processing (for in-game payments), analytics, social integration, and more. Check the links to the left for further documentation on all these features.
A great tool to use is the sandbox for testing and learning API calls.
We take customer support, and the quality of our developer tools and documentation very seriously. We want to hear how you think we can improve our documentation! Let us know if anything is missing, or unclear on this documentation page, and we'll get that fixed!