Messaging apps in general are becoming a second home screen for many people, acting as their entry point to the Internet; where the "youngins" are, the brands will follow. Companies are coming up with messaging apps as bots and apps that offer everything from customer service to online shopping and banking.

Conversations are shaping up to be the next major human-computer interface. Thanks to advances in natural language processing and machine learning, the technology is finally getting faster and accurate enough to be viable. Imagine a platform where language is the new UI layer. When we talk about conversation as a platform, there are three parts:

• There are people talking to people. The Skype translator is an example where people can communicate across languages.
• Then, there is the opportunity to enhance a conversation by the ability to be present and interact remotely.
• Then, there are personal assistants and the bots.

The following screenshot shows the Conversation as a Service:

Think of bots as the new mechanism that you can converse with. Instead of looking through multiple mobile apps or pages of websites, you can call on any application as a bot within the conversational canvas. Bots are the new apps, and digital assistants are the meta-apps. This way, intelligence is infused into all our interactions.

This leads us to the Microsoft Bot Framework, which is a comprehensive offering from Microsoft to build and deploy high quality bots for your users to interact using Conversation as a Platform (CaaP). This is a framework that lets you build and connect intelligent bots. The idea is that they interact naturally wherever your users are talking, such as Skype, Slack, Facebook Messenger, text/SMS, and others. Basically, with any kind of channel that you use today as a human being to talk to other people, you will be able to use them to talk to bots, all using natural language:

The Microsoft Bot Framework is a Microsoft operated CaaP service and an open source SDK. The Microsoft Bot Framework is one of the many tools that Microsoft is offering for building a complete bot. Other tools include Language Understanding Intelligent Service (LUIS), Speech APIs, Microsoft Azure, Cortana Intelligence Suit, and many more.

The Microsoft Bot Builder SDK is one of three main components of the Microsoft Bot Framework. First, you have to build your bot. Your bot lives in the cloud and you host it yourself. You write it just like a web service component using Node.js or C#, like the ASP.NET Web API component. The Microsoft Bot Builder SDK is open source, so it will support more languages and web stacks over time. Your bot will have its own logic, but you also need a conversation logic using dialogs to model a conversation. The Bot Builder SDK gives you facilities for this, and there are many types of dialogs that are included, from simple yes or no questions, to full LUIS, which is one of the APIs provided by Microsoft Cognitive Services. This is what the architecture of bot looks like:

The Bot Connector is hosted and operated by Microsoft. Think of it as a central router between your bots and many channels to communicate with your bots. Apart from routing messages, it manages state within the conversation. The Bot Connector is an easy way to create a single backend and then publish it to a bunch of different platforms called channels.

The following screenshot illustrates the Bot Connector:

The Bot Directory is where the user will be able to find bots. It's like an App Store for mobile apps. The Bot Directory is a public directory of all the reviewed bots registered through the developer portal. Users will be able to discover, try, and add bots to their favorite conversation experiences from the Bot Directory. Anyone can access it and can submit bots to the directory.

As you begin your development with the Microsoft Bot Framework, you might be wondering how best to get started. Bots can be built in C#; however, Microsoft's Bot Framework can also be used to build bots using Node.js. For developing any bots, we need to first set up the development environment and have the right tools installed for successfully developing and deploying a bot. Let's see how we can set up a development environment using Visual Studio.

In this section, we will see how to set up the development environment but, before that, let's check out the prerequisites needed for setting it up.

To use the Microsoft Bot Framework Connector, you must have the following:

• A Microsoft account (Hotmail, Live, or Outlook) to log into the Bot Framework developer portal, which you will use to register your bot.
• An Azure subscription (free trial at https://azure.microsoft.com/en-us/). This Azure subscription is essential for having an Azure-accessible REST endpoint exposing a callback for the Connector service.
• Developer accounts on one or more communication service (such as Skype, Slack, or Facebook) where your bot will communicate.

In addition, you may wish to have an Azure Application Insights account so that you can capture telemetry from your bot. There are additionally different ways to go about building a bot: from scratch, coded directly to the Bot Connector REST API, the Bot Builder SDK's for Node.js and .NET, and the Bot Connector .NET template, which is what this quick start guide demonstrates.

This is a step-by-step guide to setting up the development environment to develop a bot in C# using the Bot Framework Connector SDK .NET template:

1. Install the prerequisite software:
   1. You can download the community version of Visual Studio 2015 (latest update) for free at www.visualstudio.com.
   2. Update all VS extensions to their latest versions by navigating to Tools | Extensions and Updates | Updates.
2. Download and install the Bot Application template:
   1. Download the file from the direct download link, http://aka.ms/bf-bc-vstemplate.
   2. Save the ZIP file to your Visual Studio 2015 templates directory, which is traditionally in %USERPROFILE%DocumentsVisual Studio 2015TemplatesProjectTemplatesVisual C#.
3. Open Visual Studio.

4. Create a new C# project using the new Bot Application template:

5. The template is a fully functional Echo Bot that takes the user's text utterance as input and returns it as output. In order to run, however, the following has to take place:
   1. The bot has to be registered with the Bot Connector.
   2. The AppId and AppPassword from the Bot Framework registration page have to be recorded in the project's web.config.
   3. The project needs to be published to the web.
   4. Use the Bot Framework emulator to test your bot application.

The Bot Framework provides a channel emulator that lets you test calls to your bot as if they were being called by the Bot Framework cloud service. To install the Bot Framework emulator, download it from https://emulator.botframework.com/.

Once installed, you're ready to test, by starting your bot in Visual Studio using a browser as the application host:

Your bot can send rich text, emoticons, pictures, and cards to a user or group. Users can send rich text and pictures to your bot. You can specify the type of content your bot can handle in the Skype settings page for your bot:

Content	From user to bot	From bot to user	Description
Rich text			Including emoticons :)
Pictures			PNG, JPEG, or GIF up to 20 Mb
Video	Coming soon		MP4, AAC+h264 up to 15 Mb (approx. 1 minute), plus JPEG thumbnail
Cards

Each Skype user is assigned a unique ID for your bot, which is sent along with the display name with every message:

{ 
  "text": "Hello (wave)", 
  "id": "1466182688092", 
  "type": "message/text", 
  "timestamp": "2016-06-17T16:58:08.74Z", 
  "channelId": "skype", 
  "serviceUrl": "https://apis.skype.com", 
  "from": { 
    "id": "29:2hJJkjmGn4ljB2X7YYEju-sgFwgvnISvE6G3abGde8ts", 
    "name": "Display Name" 
  }, 
  "conversation": { 
    "id": "29:2hJJkjmGn4ljB2X7YYEju-sgFwgvnISvE6G3abGde8ts" 
  }, 
  "recipient": { 
    "id": "28:29415286-5a43-4a00-9dc5-bcbc2ce1f59e", 
    "name": "Trivia Master" 
  } 
} 

The from field contains the unique user ID (prefixed by 29) and user Display Name. The recipient field contains the app ID (prefixed by 28, which indicates a bot in Skype) and the bot's display name. In Skype, your bot is addressed using the Bot Framework App ID (a GUID).

Users can communicate with the bot using rich text format as well. Users can make the chat text as bold if needed or a bot can communicate with the user and make certain words as bold. Most of the channels support all the text properties supported by the Microsoft Bot Framework.

Skype emoticons can be sent by using the emoticon keyword in parentheses:

{
  "text": "(heart)"
}

The output of the preceding code is as follows:

To send a welcome message to a user, listen for the contactRelationUpdate activity. To send a welcome message to a group, listen for the conversationUpdate activity.

Let's check out, how pictures and videos are sent:

• Pictures and videos are sent by adding attachments to a message
• Pictures can be PNG, JPEG, or GIF up to 20 Mb
• Videos can be MP4 or AAC+h264 up to 15 Mb (approx. 1 minute), plus JPEG thumbnails

Skype supports the following cards, which may have several properties and attachments. You can find information on how to use cards in the .NET SDK and Node.js SDK docs:

• Hero card
• Thumbnail card
• Carousel card (with hero or thumbnail images)
• Sign in card
• Receipt card

Images sent to Skype cards need to be stored on an HTTPS endpoint. Skype cards do not currently support postBack actions.

The hero card renders a title, subtitle, text, large image, and buttons:

The hero card provides a very flexible layout; for example, it might contain the following:

• Image, title, subtitle, text, and three buttons
• Title, subtitle, text, and five buttons
• Title and six buttons
• Image and six buttons

The following table illustrates the flexible layout of hero card:

The thumbnail card renders a title, subtitle, text, small thumbnail image, and buttons:

The following table explains the properties of a thumbnail card:

The carousel card can be used to show a carousel of images and text, with associated action buttons:

Properties are the same as for the hero or thumbnail card.

Images are scaled up or down in size while maintaining the aspect ratio to cover the image area, and then cropped from the center to achieve the image aspect ratio for the card.

Images should be stored on an HTTPS endpoint, up to 1024x1024, up to 1 MB in size, and in PNG or JPEG. The properties are explained in the following table:

Buttons are shown at the bottom of the card--in a single row if they fit, or stacked. Button text is always on a single line and will be trimmed if it is too long. If more buttons than can be supported by the card are included, they will not be shown.

The following table consists of properties, types and descriptions for actions:

The sign in card can be used to initiate an authentication flow with predefined images and title:

The following table illustrates the properties, types and descriptions of sign in:

The receipt card can be used to send a receipt. If the height of the card is too large, it is partially folded and a Show all action is shown to expand it:

The following table explains the properties, types and descriptions of receipt card:

A bot can be enabled for groups in the Skype settings for the bot. It can be added to a group chat in the same way as adding a participant to a chat. In a group, the bot will only receive messages directly addressed to it--for example, @YourBot This is the message. It will not receive other messages sent by group participants or notifications of users joining or leaving the group:

To enable a bot to be added to a group chat, you need to add this capability in Settings. Go to your bot Dashboard and edit the Skype channel:

You can build Skype bots that can receive and handle voice calls using the .NET SDK, Node.js SDK, or the Skype API.

Each time a Skype user places a call to your bot, the Skype bot platform will notify the bot using the calling WebHook you specify in Settings. In response, the bot can provide a set of basic actions called a workflow.

These are the supported actions:

• Answer
• Play prompt
• Record audio
• Speech to text
• DTMF tones
• Hang up

The Skype bot platform will execute the actions on the bot's behalf according to the workflow.

If the workflow is successful, Skype will post a result of the last action to your calling WebHook. For example, if the last action was to record an audio message, the result will be audio content.

During a voice call, your bot can decide, after each result, how to continue interaction with the Skype user.

In this chapter, we introduced the Microsoft Bot Framework and explained how it helps in the development of bots. Also, we have seen how to set up the development environment, emulator, and the tools needed for programming. This chapter is based on the thought that programming knowledge and experience grow best when they grow together. In the next chapter, we will introduce bot programming by building and locally deploying a simple Hello World bot application. You will get to know Visual Studio, C# .NET, the Bot Framework, and the related technologies along with all the steps for creating projects.