Botkit reply to Slack with attachments (from https://github.com/howdyai/botkit#botreply)

botkit_slack_attachments.js

var reply_with_attachments = {
  'username': 'My bot' ,
  'text': 'This is a pre-text',
  'attachments': [
    {
      'fallback': 'To be useful, I need you to invite me in a channel.',
      'title': 'How can I help you?',
      'text': 'To be useful, I need you to invite me in a channel ',
      'color': '#7CD197'
    }
  ],
  'icon_url': 'http://lorempixel.com/48/48'
}

bot.reply(message, reply_with_attachments);