Answers

Discord waits 3 seconds for the first answer to an interaction. A handler returns one of these answers:

Answer	What Discord shows
`c.reply(text, options)`	A new message.
`c.defer(work, { ephemeral })`	“Thinking…”, then the result of `work`. Use it for work that takes over 3 seconds.
`c.update(text, options)`	Buttons and menus only: the message of the button or menu, edited.
`c.deferUpdate(work)`	Buttons and menus only: the same message, then edited with the result of `work`.
`c.modal(form, value)`	A form in a popup. See Modals.

Message options

reply, update, send and the result of defer take the same options:

c.reply('Report ready', {
  embeds: [{ title: 'Uptime', description: '99.9%', color: 0xff6a4d }],
  buttons: [{ id: 'refresh', label: 'Refresh' }],
  files: [{ name: 'report.csv', data: 'name,count\napple,3\n' }],
  ephemeral: true,
});

Option	What it does
`embeds`	Embeds, with the fields that Discord accepts.
`buttons`	Buttons. See Buttons and menus.
`selects`	Select menus. See Buttons and menus.
`files`	Files to attach. Each has a `name`, `data` and an optional `description`.
`allowedMentions`	Who the message can ping. See below.
`ephemeral`	`reply` and `defer` only. Shows the message to the user who ran the command only.

data in a file can be a string, an ArrayBuffer, a Uint8Array or a Blob.

Slow work

command({ name: 'report', description: 'Build a report' }, (c) =>
  c.defer(async () => {
    const rows = await buildReport();

    return { content: `${rows.length} rows`, files: [{ name: 'report.csv', data: toCsv(rows) }] };
  }),
);

work returns the text, or an object with content and the message options. If work throws, the answer changes to “Something went wrong.” and onError gets the error.

Mentions

Messages ping nobody by default, even when the text has @everyone or <@id>. To ping, pass allowedMentions:

import { mention, time } from 'botflare';

c.reply(`${mention.user(user)}, your turn ${time(Date.now(), 'relative')}`, {
  allowedMentions: { users: [user.id] },
});

mention has user, role, channel and command. time writes a timestamp that Discord shows in the time zone of each reader. Its styles are short, long, short-date, long-date, short-time, long-time and relative.

Follow-ups

To send more after the first answer, call c.after(work) before you return the answer. work runs after Discord has the answer:

command({ name: 'poll', description: 'Start a poll' }, (c) => {
  c.after(async () => {
    await c.followUp('Vote with the buttons below', { ephemeral: true });
    await c.editReply('Poll is open');
  });

  return c.reply('Opening the poll…');
});

Call	What it does
`c.followUp(text, options)`	Sends a new message.
`c.editReply(text, options)`	Edits the first answer.
`c.deleteReply()`	Deletes the first answer.

Each returns an Error if Discord refuses, or null. The work of defer and deferUpdate can call them too.