Quick demo of responding to bot mentions using Wonder Llama: https://github.com/raws/wonder-llama

wonder-llama-demo.rb

require 'bundler/inline'

gemfile do
  gem 'wonder-llama', github: 'raws/wonder-llama', branch: 'master', require: 'wonder_llama'
end

def bot_mentioned?(message)
  message.content.include?('@**Ralph**')
end

client = WonderLlama::Client.new(host: ENV['ZULIP_HOST'], email: ENV['ZULIP_EMAIL'],
  api_key: ENV['ZULIP_API_KEY'])

client.stream_events do |event|
  if event.is_a?(WonderLlama::MessageEvent) && (event.message.private? || bot_mentioned?(event.message))
    sender = event.message.params[:sender_full_name]
    event.message.reply("Hi there, @**#{sender}**! :wave:")
  end
end