How to add license keys to a Minecraft plugin in 10 minutes

Adding license keys to a Minecraft plugin can prevent unauthorized distribution and limit usage to a specific number of servers. This tutorial outlines how to implement licensing in a Paper plugin using BuiltByBit's DRM guidance, all within approximately ten minutes.

To start, create a product and a policy on BuiltByBit's platform. This can be done in just two minutes by signing up for a free account, creating a new product, and setting a maximum of two machines per purchase. Next, generate an API key for your plugin to use in checking licenses. It is crucial to keep this key secure and out of version control systems.

The fastest way to add licensing checks to your plugin is by starting with a free Paper plugin template. This template incorporates BuiltByBit's recommended elements, including the SDK, console messages for license validation results, automatic re-checking every few hours, and an offline license fallback to ensure the plugin continues running when the license server is unreachable.

To set up the API key, add it to your project's gradle.properties file. Then, modify the CoreFeatures.java file to include the license validation logic. This code checks the license validity upon plugin startup and then every six hours. If the license is invalid, the plugin disables itself. If the server can't be reached, the plugin will still run, respecting BuiltByBit's DRM guidance and avoiding being flagged as malicious.

In summary, by following these steps, you can add license keys to your Minecraft plugin in a matter of minutes, offering a unique key to each buyer, limiting the number of servers per key, and ensuring your plugin doesn't disrupt other users if a copy is leaked.