Event-driven workflows

Commands are not the only entry point. You can attach logic to Discord events such as:

Event family	Typical use
messageCreate	Auto-moderation, keyword triggers
guildMemberAdd	Welcome messages, auto-roles
interactionCreate	Buttons, select menus, modals, slash commands
voiceStateUpdate	Voice channel logging

Each event workflow runs with the variables of its own event (for example the interaction events set interaction.kind and interaction.customId).

Placeholders ((...))

Placeholders insert runtime values into response messages, embeds, components and workflow inputs of Blocks and visual responses. They are resolved when the bot executes — not at design time.

Welcome ((user.username))! You joined ((guild.name)).

BDScript text is not resolved. The ((...)) resolver is not applied to the text of a native BDFD script (probe: Hi ((date)) is returned unchanged). In a BDFD script use the $functions, for example $username and $serverName.

Core placeholder families

Prefix	Examples
((user.*))	((user.id)), ((user.username)), ((user.avatar))
((member.*))	((member.nick)), ((member.joinedAt)), ((member.roles))
((guild.*))	((guild.name)), ((guild.memberCount))
((channel.*))	((channel.id)), ((channel.name))
((message.*))	((message.content)), ((message.id))
((interaction.*))	((interaction.customId)), ((interaction.kind))
((opts.*))	((opts.reason)), ((opts.target.id)) (slash command options: for user, channel, role and mentionable options the ID is opts.<name>.id; modal inputs are also stored as opts.<key>)

Interaction placeholders

When a user clicks a button or submits a modal, interaction placeholders are populated automatically.

BDScript (BDFD) reads the custom ID with $customID (valid in a component or modal interaction):

$ephemeral
Clicked: $customID

Blocks:

{
  "type": "respondWithMessage",
  "payload": {
    "content": "Clicked: ((interaction.customId))",
    "ephemeral": true
  }
}

See Interactions overview for component-specific patterns.

Full reference

Resource	Scope
Template system	Complete ((...)) syntax, fallbacks, JSONPath, inline functions
Exhaustive event variables guide	Every variable per event type
JavaScript placeholders	BDJS usage of ((...)) patterns

BDScript vs JavaScript

• BDScript: use $functions; ((...)) text inside a BDFD script is left as typed.
• JavaScript: see variables and placeholders.

Next steps

1. Persistent variables ($getUserVar, $setUserVar) — see the Database variables guide.
2. Build your first event workflow with Create Your First Command.