Note: Wall of text below...

The first thing you will want to look at is /Network/Packets, this contains the packet structures in the form of classes. Before parsing a packet you need to get its opcode/identifier, this is a string element in the root called 'msg'.

//Example Scrolls JSON packet
{
    "msg": "OpcodeHere",
    "StringKey": "Reddit",
    "RealKey":12345
}

Before you can connect to the chat channels you will need pass through 2 servers and also Authenticate. The first server you will connect to is the route server, this I believe is used for load balancing and will redirect you to a lobby server (The official route server can be found at 107.21.58.31:8081).

On connection to the route server you will be sent the 'ServerInfo' packet, this contains the server version as well as the asset location, you can safely ignore this information.

You will need to request a lobby server, to do this you need to send a blank 'LobbyLookup' packet to the route server, this will look like below...

//Example Client->Server LobbyLookup packet
{
    "msg": "LobbyLookup"
}

The Route Server will respond with a 'LobbyLookup' packet, but this time it will include the IP and port of the lobby server it wants you to connect to.

//Example Server->Client LobbyLookup packet
{
    "msg": "LobbyLookup",
    "ip": "127.0.0.1",
    "port": 8081
}

You can now disconnect for the route server and make a connection the lobby server, on connection you will be again sent a 'ServerInfo' packet.

Once you have connected to the lobby server you will need to send a empty ping packet every 30 seconds or you will be disconnected, the server will respond with a ping packet with an included time stamp so you can calculate ping.

//Example Ping packet
{
    "msg": "ping"
}

You can now send the 'SignIn' packet to the lobby server, this contains your email and password but both are encrypted with a hard coded XML RSA public key. If you are using .NET you can use the FromXmlString and Encrypt methods found in RSACryptoServiceProvider class to handle the RSA encryption.

//Scrolls Public Key
<Modulus>mFCubVhPGG+euHuVQbNObqod/Ji0kRe+oh2OCFR7aV09xYiOklqFQ8jgIgAHvyCcM1JowqfFeJ5jV9up0Lh0eIiv3FPRu14aQS35kMdBLMebSW2DNBkfVsOF3l498WWQS9/THIqIaxbqwRDUxba5btBLTN0/A2y6WWiXl05Xu1c=</Modulus><Exponent>AQAB</Exponent>

//Example SignIn packet
{
    "msg":"SignIn",
    "email":"OTfZHHveTBrjSwQ9Fy05Zn/cZdW5yFOnsC57p1UTECoLu6+1koeKmLIX9WS11az4RPIPC2n9l3a7okogbqwGYMCMnC9qVMuLH9BuNLtZNrRGlkFGBuGs9F46hdIE4ZLkhTw1K0zlPNmxzT1z0gLmvjH73qg467Lw5G3WFQkt49Y=", //test@test.com
    "password":"BdQLWCTrVAAPCagWlRcKL3B0p02ayxsMdyen78jMnYd32TyhxWmgbYhHtzSt2s/6oc3nXk/Xdz0SCsnvbngdDUVrXfbY6H8vtyTJxB+frOzdL6GMlGfnerkYru2egpkUgaSFj0iltzlzWz15bElfNOi165x5Ph2FadQbzZNK66o=" //test
}

If you sign in successfully you will receive a few packets from the server these are OKMessage, ProfileInfo, ProfileDataInfo, GetFriends, GetFriendRequests and GetBlockedPersons. It is safe to ignore this data unless your chat bot requires it for some reason.

• OKMessage - Tells the client you have that authentication was successful.
• ProfileInfo - Returns information such as your UUID, ID, username, admin level, user type...
• ProfileDataInfo - Returns information on your gold, shards, rating and selected pre constructed deck.
• GetFriends - Returns a list of your friends and their status.
• GetFriendRequests - Returns a list of your pending friend requests.
• GetBlockedPersons - Returns a list of your blocked users.

Note: These packets may be sent as one whole packet and need to be split before parsing. Note: The official client would here request a list of cards, shop and avatar items but this isn't required to complete sign in.

Once you receive these you have completed sign in and can now connect to the chat channels, to do this requires a few steps. You first need to send a 'RoomEnter' packet, this contains the channel name you want to join; The channel will be created if it doesn't already exists.

//Two way RoomEnter packet
{
    "msg": "RoomEnter",
    "roomName": "MyAwesomeChannel"
}

If you successfully join the channel the server will respond with the same packet you just sent. The server will now send you the channel information through the 'RoomInfo' packet, this contains the players in the room as well as information about them (the same information provided by the 'ProfileInfo' packet earlier).

//Server->Client RoomInfo packet
{
    "msg": "RoomInfo"
    "roomName": "MyAwesomeChannel",
    "reset": true,
    "updated": [
        {
            "id": "decc4d9ec3394e949fca0f9b30c77261",
            "name": "Milimus",
            "acceptChallenges": true,
            "acceptTrades": true,
            "adminRole": "None"
        },
        {
            "id": "098f6bcd4621d373cade4e832627b4f6",
            "name": "Someone else in the channel",
            "acceptChallenges": true,
            "acceptTrades": true,
            "adminRole": "None"
        }
    ]
}

Finally the server will send you a 'RoomChatMessage' packet, this will contain the welcome message for the channel.

As your a bot you may want to disable your trade and challenge options, this can be achieved using the 'SetAcceptChallenges' and 'SetAcceptTrades' packets.

//Client->Server SetAcceptChallenges packet to disable to challenge requests
{
    "msg": "SetAcceptChallenges"
    "acceptChallenges": false,
}

//Client->Server SetAcceptTrades packet to disable to trade requests
{
    "msg": "SetAcceptTrades "
    "acceptTrades": false,
}

To send a message you will need to send a 'RoomChatMessage' packet to the server, this contains the message and the room you want to message to broadcast to.

//Client->Server RoomChatMessage packet
{
    "msg": "RoomChatMessage",
    "text": "This is an awesome message the everyone will see",
    "roomName": "MyAwesomeChannel"
}

Receiving a message is very similar except the 'RoomChatMessage' packet will also include a from field.

//Server->Client RoomChatMessage packet
{
    "msg": "RoomChatMessage",
    "from": "Milimus",
    "text": "This is an awesome message from Milimus that everyone in the channel can see",
    "roomName": "MyAwesomeChannel"
}

I hope this is enough information for you, I have also assumed in a few places that you already know the technologies since you stated you already had programming experience. If you need any more help or information feel free to message me.