Bukkit

Plan:

• Add mcMastery as a local dependency, and state it inside your plugin.yml.
• On your plugin onEnable, registerAbility(Ability_Here.class).
• Implement Ability interface in said ability class.
• Use @AbilityAttributes on the class and declare stuff.
• Return number from initiate method.
• Add your permissions if you are using into plugin.yml just in case.

Steps

• Add mcMastery as a local dependency.
• Use the Assets class.
• Either use DefaultAssets or PlayerAssets enums from that class.
• Use methods getData() or setData(), player argument may be required depending on variable type.

Check out GitHub for this class. Now you can develop your plugins to edit player data externally for mcMastery, or access its data for your devilish purposes.