Addon Development

Learn how to build your own features and extensions for Kythia.

Addons are the lifeblood of Kythia. Every feature—from simple pings to complex AI interactions—is implemented as an addon. This structure makes Kythia incredibly easy to maintain and extend.

Every addon lives in its own folder within the addons/ directory.

This file tells Kythia's AddonManager how to load your feature.

{
  "name": "MyAwesomeAddon",
  "version": "1.0.0",
  "description": "Adds a cool new feature to your server.",
  "active": true
}

Let's build a simple /echo command that repeats whatever the user says.

// addons/hello-world/commands/echo.js

const { SlashCommandBuilder } = require('discord.js');

module.exports = {
  slashCommand: new SlashCommandBuilder()
    .setName('echo')
    .setDescription('Repeats your message')
    .addStringOption(option => 
      option.setName('message').setDescription('The message to repeat').setRequired(true)
    ),

  async execute(interaction, container) {
    const { logger } = container;
    const message = interaction.options.getString('message');

    logger.info(`User ${interaction.user.tag} used echo: ${message}`);
    await interaction.reply({ content: `You said: ${message}` });
  }
};

Addons can also listen to any Discord event. Create an events/ folder and add a file named after the event you want to hear.

// addons/hello-world/events/MessageCreate.js

module.exports = {
  name: 'messageCreate',
  async execute(message, container) {
    if (message.author.bot) return;

    if (message.content.includes('hello kythia')) {
      await message.reply('Hello! I am here to help. 🌸');
    }
  }
};

Kythia is built for a global audience. Never hardcode strings! Use the lang/ folder.

1. Create addons/hello-world/lang/en.json:

   {
     "hello": {
       "greeting": "Hello {user}! Welcome to the server."
     }
   }
   

2. Use it in your command:

   const { t } = container;
   await interaction.reply(await t(interaction, 'hello.greeting', { user: interaction.user.username }));
   

Once your files are in place:

1. Ensure active: true is set in your addon.json.
2. Add your addon to the addons block in kythia.config.js (optional, but good for control).
3. Restart the bot.
4. Run npx kythia deploy to register your new slash commands with Discord.