Slash commands

Register an application command with Bot:slash_command. Commands are synchronized automatically after the gateway ready event unless auto_sync_commands is disabled.

local OPTION = discord.enums.OPTION_TYPE

bot:slash_command("echo", {
    description = "Repeat text",
    options = {
        {
            name = "text",
            description = "Text to repeat",
            type = OPTION.STRING,
            required = true,
        },
    },
    callback = function(ctx)
        ctx:respond(ctx:require_arg("text"))
    end,
})

Each option needs a string name and numeric type. description, required, choices, and autocomplete are passed through when serializing the command. Use ctx:get_arg(name, default) for optional values and ctx:require_arg(name) for required values.

Guild-scoped commands

Use guild_ids to synchronize a command into specific guilds instead of globally:

bot:slash_command("debug", {
    description = "Development command",
    guild_ids = { "123456789012345678" },
    callback = function(ctx)
        ctx:respond("OK")
    end,
})

Autocomplete

Bot:slash_command returns an ApplicationCommand. Attach an autocomplete callback to an option name:

local command = bot:slash_command("search", {
    description = "Search an item",
    options = {
        { name = "query", description = "Search term", type = OPTION.STRING, required = true },
    },
    callback = function(ctx)
        ctx:respond("Submitted")
    end,
})

command:set_autocomplete("query", function(ctx)
    return {
        { name = "first", value = "first" },
        { name = "second", value = "second" },
    }
end)

The callback receives an AutocompleteContext. Its exact focused-option data is derived from the incoming interaction; keep returned choices within Discord's application-command constraints.

Responses

The initial ctx:respond or ctx:reply call must acknowledge the interaction within Discord's three-second window. Use ctx:defer() followed by ctx:edit(...) for slower work, then use follow-up methods as needed. Details are in Interactions and responses.