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Param Decorators

Param decorators let you extract specific values from the execution context directly in the execute() method, keeping handlers clean and free of boilerplate.

@Ctx()​

Injects the raw ExecutionContext, which wraps the underlying interaction and exposes its name and type.

execute(@Ctx() ctx: ExecutionContext) {
  console.log(ctx.name); // 'ping'
}

@Guild()​

Injects the Guild object from the interaction. Returns null if the command was used in a DM.

execute(@Guild() guild: Guild | null) {
  return guild ? guild.name : 'DM';
}

@Author()​

Injects the User who triggered the interaction.

execute(@Author() user: User) {
  return `Hello, ${user.username}!`;
}

Combining decorators​

You can use multiple param decorators in a single execute() method:

execute(@Author() user: User, @Guild() guild: Guild | null): string {
  return `${user.username} in ${guild?.name ?? 'DMs'}`;
}

How they work​

Param decorators are resolved by the CommandExecutor via a registry of paramResolvers. Each resolver receives the ExecutionContext and returns the value to inject at that parameter position. The discord.js adapter registers resolvers for CONTEXT, GUILD, and AUTHOR on initialization.

TODO: custom param decorators​

In the future, we will expose a way for users to create their own custom param decorators and register them in the executor...