Either with own code (in case of the brand name it could just listen to the plugin message) or by depending on other plugins: - [ClientDetector](https://www.spigotmc.org/resources/clientdetector-client-mod-detection-forge-mod-detection-clientcontrol.90375/) (Open source, has API but no deployed maven artifact) - [ProtocolFirewall](https://www.spigotmc.org/resources/%E2%98%84%EF%B8%8Fprotocolfirewall-%E2%94%82-server-protection-shield-1-8-9-1-18-1.86084/) (Paid, no API?) - Others? Possible that this needs to be implemented in the parent plugin and not here as that could be a lot easier there.