Command Interfaces

Introduction

Commands are the core building blocks of nsCore.
This module defines how both slash commands and prefix-based message commands are structured and executed.

By using TypeScript interfaces, nsCore ensures:

• Strong type safety
• Consistent command structure
• Easy onboarding for new contributors

SlashCommand Interface

The SlashCommand interface represents a Discord slash command (/command).

It is used when handling interactionCreate events.

Interface Definition

import { ChatInputCommandInteraction, PermissionResolvable, SlashCommandBuilder } from 'discord.js'
import { ExtendedClient } from './ExtendedClient'

export interface SlashCommand {
  name: string
  description?: string
  data: SlashCommandBuilder
  executeSlash: (interaction: ChatInputCommandInteraction, client: ExtendedClient) => Promise<void>
  userPermissions?: PermissionResolvable[]
  botPermissions?: PermissionResolvable[]
  devOnly?: boolean
}

Required Properties

name

name: string

The internal name of the command.

• Used for command registration
• Must match the slash command name in Discord

data

data: SlashCommandBuilder

Defines the slash command structure:

• Name
• Description
• Options
• Subcommands

This is what Discord uses to register the command.

executeSlash

executeSlash: (interaction: ChatInputCommandInteraction, client: ExtendedClient) => Promise<void>

The function that runs when the command is executed.

• Receives the interaction
• Has full access to the ExtendedClient

Optional Properties

userPermissions

userPermissions?: PermissionResolvable[]

Permissions required by the user to run the command.

Example:

userPermissions: ['ManageGuild']

botPermissions

botPermissions?: PermissionResolvable[]

Permissions required by the bot itself.

Example:

botPermissions: ['SendMessages']

devOnly

devOnly?: boolean

Marks the command as developer-only.

MessageCommand Interface

The MessageCommand interface represents prefix-based commands, such as:

ns.help
ns.weather

These commands are triggered via the messageCreate event.

Interface Definition

import { Message, PermissionResolvable } from 'discord.js'
import { ExtendedClient } from './ExtendedClient'

export interface MessageCommand {
  name: string
  description?: string
  executeMessage: (message: Message, args: string[], client: ExtendedClient) => Promise<void>
  userPermissions?: PermissionResolvable[]
  botPermissions?: PermissionResolvable[]
  devOnly?: boolean
}

Required Properties

name

name: string

The command name without prefix.

Example:

ns.help → name: "help"

executeMessage

executeMessage: (message: Message, args: string[], client: ExtendedClient) => Promise<void>

Runs when the command is triggered.

• args contains arguments split from the message
• client gives access to commands, events, and bot state

Optional Properties

The following behave exactly the same as in SlashCommand:

• userPermissions
• botPermissions
• devOnly

This keeps both command systems consistent.

Command Union (IMPORTANT)

The Command type is a union of both command types.

Definition

export type Command = SlashCommand | MessageCommand

Why This Matters

The union allows:

• Unified command loaders
• Shared validation logic
• Cleaner architecture

Example use case:

function registerCommand(command: Command) {
  if ('data' in command) {
    // SlashCommand
  } else {
    // MessageCommand
  }
}

Design Philosophy

nsCore separates commands by how they are triggered, not by logic.

• Slash commands → Interactions
• Message commands → Messages
• Shared permission + dev logic

This keeps the system:

• Clean
• Predictable
• Easy to extend

Summary

• SlashCommand → Modern Discord interactions
• MessageCommand → Traditional prefix commands
• Command → Unified abstraction

Together, these interfaces form the command foundation of nsCore.

Next, you’ll learn how these commands are loaded, registered, and executed using the ExtendedClient.