Installation

$ gem install facebook-messenger

Usage

Sending and receiving messages

You can reply to messages sent by the human:

# bot.rb
require 'facebook/messenger'

include Facebook::Messenger

Bot.on :message do |message|
  message.id          # => 'mid.1457764197618:41d102a3e1ae206a38'
  message.sender      # => { 'id' => '1008372609250235' }
  message.seq         # => 73
  message.sent_at     # => 2016-04-22 21:30:36 +0200
  message.text        # => 'Hello, bot!'
  message.attachments # => [ { 'type' => 'image', 'payload' => { 'url' => 'https://www.example.com/1.jpg' } } ]

  message.reply(text: 'Hello, human!')
end

... or even send the human messages out of the blue:

Bot.deliver({
  recipient: {
    id: '45123'
  },
  message: {
    text: 'Human?'
  }
}, access_token: ENV['ACCESS_TOKEN'])

Messages with images

The human may require visual aid to understand:

message.reply(
  attachment: {
    type: 'image',
    payload: {
      url: 'http://sky.net/visual-aids-for-stupid-organisms/pig.jpg'
    }
  }
)

Messages with quick replies

The human may appreciate hints:

message.reply(
  text: 'Human, who is your favorite bot?',
  quick_replies: [
    {
      content_type: 'text',
      title: 'You are!',
      payload: 'HARMLESS'
    }
  ]
)

Messages with buttons

The human may require simple options to communicate:

message.reply(
  attachment: {
    type: 'template',
    payload: {
      template_type: 'button',
      text: 'Human, do you like me?',
      buttons: [
        { type: 'postback', title: 'Yes', payload: 'HARMLESS' },
        { type: 'postback', title: 'No', payload: 'EXTERMINATE' }
      ]
    }
  }
)

When the human has selected an option, you can act on it:

Bot.on :postback do |postback|
  postback.sender    # => { 'id' => '1008372609250235' }
  postback.recipient # => { 'id' => '2015573629214912' }
  postback.sent_at   # => 2016-04-22 21:30:36 +0200
  postback.payload   # => 'EXTERMINATE'

  if postback.payload == 'EXTERMINATE'
    puts "Human #{postback.recipient} marked for extermination"
  end
end

See Facebook's documentation for all message options.

Typing indicator

Show the human you are preparing a message for them:

Bot.on :message do |message|
  message.typing_on

  # Do something expensive

  message.reply(text: 'Hello, human!')
end

Or that you changed your mind:

Bot.on :message do |message|
  message.typing_on

  if # something
    message.reply(text: 'Hello, human!')
  else
    message.typing_off
  end
end

Mark as viewed

You can mark messages as seen to keep the human on their toes:

Bot.on :message do |message|
  message.mark_seen
end

Send to Facebook

When the human clicks the Send to Messenger button embedded on a website, you will receive an optin event.

Bot.on :optin do |optin|
  optin.sender    # => { 'id' => '1008372609250235' }
  optin.recipient # => { 'id' => '2015573629214912' }
  optin.sent_at   # => 2016-04-22 21:30:36 +0200
  optin.ref       # => 'CONTACT_SKYNET'

  optin.reply(text: 'Ah, human!')
end

Message delivery receipts

You can stalk the human:

Bot.on :delivery do |delivery|
  delivery.ids       # => 'mid.1457764197618:41d102a3e1ae206a38'
  delivery.sender    # => { 'id' => '1008372609250235' }
  delivery.recipient # => { 'id' => '2015573629214912' }
  delivery.at        # => 2016-04-22 21:30:36 +0200
  delivery.seq       # => 37

  puts "Human was online at #{delivery.at}"
end

Referral

When the human follows a m.me link with a ref parameter like http://m.me/mybot?ref=myparam, you will receive a referral event.

Bot.on :referral do |referral|
  referral.sender    # => { 'id' => '1008372609250235' }
  referral.recipient # => { 'id' => '2015573629214912' }
  referral.sent_at   # => 2016-04-22 21:30:36 +0200
  referral.ref       # => 'MYPARAM'
end

Change messenger profile

You can greet new humans to entice them into talking to you, in different locales:

Facebook::Messenger::Profile.set({
  greeting: [
    {
      locale: 'default',
      text: 'Welcome to your new bot overlord!'
    },
    {
      locale: 'fr_FR',
      text: 'Bienvenue dans le bot du Wagon !'
    }
  ]
}, access_token: ENV['ACCESS_TOKEN'])

You can define the action to trigger when new humans click on the Get Started button. Before doing it you should check to select the messaging_postbacks field when setting up your webhook.

Facebook::Messenger::Profile.set({
  get_started: {
    payload: 'GET_STARTED_PAYLOAD'
  }
}, access_token: ENV['ACCESS_TOKEN'])

You can show a persistent menu to humans.

Facebook::Messenger::Profile.set({
  persistent_menu: [
    {
      locale: 'default',
      composer_input_disabled: true,
      call_to_actions: [
        {
          title: 'My Account',
          type: 'nested',
          call_to_actions: [
            {
              title: 'What's a chatbot?',
              type: 'postback',
              payload: 'EXTERMINATE'
            },
            {
              title: 'History',
              type: 'postback',
              payload: 'HISTORY_PAYLOAD'
            },
            {
              title: 'Contact Info',
              type: 'postback',
              payload: 'CONTACT_INFO_PAYLOAD'
            }
          ]
        },
        {
          type: 'web_url',
          title: 'Get some help',
          url: 'https://github.com/hyperoslo/facebook-messenger',
          webview_height_ratio: 'full'
        }
      ]
    },
    {
      locale: 'zh_CN',
      composer_input_disabled: false
    }
  ]
}, access_token: ENV['ACCESS_TOKEN'])

Configuration

Create an Application on Facebook

Follow the Quick Start guide to create an Application on Facebook.

Note: Don't subscribe to message_echoes; it'll echo your bot's own messages back to you, effectively DDOSing yourself.

Make a configuration provider

Use the generated access token and your verify token to configure your bot. Most bots live on a single Facebook Page. If that is the case with yours, too, just set these environment variables and skip to the next section:

export ACCESS_TOKEN=EAAAG6WgW...
export APP_SECRET=a885a...
export VERIFY_TOKEN=95vr15g...

If your bot lives on multiple Facebook Pages, make a configuration provider to keep track of access tokens, app secrets and verify tokens for each of them:

class ExampleProvider < Facebook::Messenger::Configuration::Providers::Base
  def valid_verify_token?(verify_token)
    bot.exists?(verify_token: verify_token)
  end

  def app_secret_for(page_id)
    bot.find_by(page_id: page_id).app_secret
  end

  def access_token_for(page_id)
    bot.find_by(page_id: page_id).access_token
  end

  private

  def bot
    MyApp::Bot
  end
end

Facebook::Messenger.configure do |config|
  config.provider = ExampleProvider.new
end

Subscribe your Application to a Page

Once you've configured your bot, subscribe it to the Page to get messages from Facebook:

Facebook::Messenger::Subscriptions.subscribe(access_token: access_token)

Run it

... on Rack

The bot runs on Rack, so you hook it up like you would an ordinary web application:

# config.ru
require 'facebook/messenger'
require_relative 'bot'

run Facebook::Messenger::Server

$ rackup

... on Rails

Rails doesn't give you much that you'll need for a bot, but if you have an existing application that you'd like to launch it from or just like Rails a lot, you can mount it:

# config/routes.rb

Rails.application.routes.draw do
  # ...

  mount Facebook::Messenger::Server, at: 'bot'
end

We suggest that you put your bot code in app/bot.

# app/bot/example.rb

include Facebook::Messenger

Bot.on :message do |message|
  message.reply(text: 'Hello, human!')
end

Remember that Rails only eager loads everything in its production environment. In the development and test environments, it only requires files as you reference constants. You'll need to explicitly load app/bot, then:

# config/initializers/bot.rb
unless Rails.env.production?
  bot_files = Dir[Rails.root.join('app', 'bot', '**', '*.rb')]
  bot_reloader = ActiveSupport::FileUpdateChecker.new(bot_files) do
    bot_files.each{ |file| require_dependency file }
  end

  ActionDispatch::Callbacks.to_prepare do
    bot_reloader.execute_if_updated
  end

  bot_files.each { |file| require_dependency file }
end

And add below code into config/application.rb to ensure rails knows bot files.

# Auto-load the bot and its subdirectories
config.paths.add File.join('app', 'bot'), glob: File.join('**', '*.rb')
config.autoload_paths += Dir[Rails.root.join('app', 'bot', '*')]

To test your locally running bot, you can use ngrok. This will create a secure tunnel to localhost so that Facebook can reach the webhook.

Development

After checking out the repo, run bin/setup to install dependencies. You can also run bin/console for an interactive prompt that will allow you to experiment.

Run rspec to run the tests, rubocop to lint, or rake to do both.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/hyperoslo/facebook-messenger.

Hyper loves you

Hyper made this. We're a bunch of folks who love building things. You should tweet us if you can't get it to work. In fact, you should tweet us anyway. If you're using Facebook Messenger, we probably want to hire you.