Server Query Protocol

Server Query Protocol

This page documents the Sky Co-op server query protocol to get infromation about server.

Query information about server.

Server will respond by same address that used for game.

Default port of Sky Co-op Server is 26950 (if not listed otherwise).

If server don't have listed port, it will respond via default 26950 port, but if server has specified port, this port will be used for query of information aswell.

Examples for easier understanding

Server Address	Game port	Query port
87.254.159.105	26950	26950
87.254.159.105:26950	26950	26950
87.254.159.105:35735	35735	35735

Query format

Send the following UDP query to a Sky Co-op server to get server status information.

Type	Field	Value
Signed Int	Message Type	-2

If everything done right, you will get reply.

Reply format

Type	Data
Signed Int	Header, always 147
Signed Int	Server name length
Unicode String	Unicode server name, use lenght you have read earlier to read this string
Signed Int	Mod version string length
UTF8 string	UTF8 formated string of mod version, use lenght you have read earlier to read this string
Signed Int	Current amout of players on server
Signed Int	Max slots for players
Signed Int	Server config json string length
Unicode String	Unicode formated json string with server config data, use lenght you have read earlier to read this string

Server config json contains experience mode selected on server (difficulty), names of players that currently on server, and status of enabled PVP.

C# Example

        public static void Ping()
        {
            // Request of server status should be done via UDP.
            // Use same port as game server use.
            // Default port of Sky Co-op Server is 26950 (if not listed otherwise).
            // Example: Game server with address 87.254.159.105:26950
            // Will respond with status data by same 26950 port,
            // aswell as servers that listed as 87.254.159.105
            // will respond by port 26950, but I think is obvious.

            // Send to server (signed int) -2 message to request servers status.

            UdpClient Pinger = new UdpClient();
            IPEndPoint endPoint = new IPEndPoint(IPAddress.Parse(ip), port);
            Pinger.Connect(endPoint);
            byte[] Buffer = BitConverter.GetBytes(-2);
            Pinger.Send(Buffer.ToArray(), Buffer.Length);

            byte[] ReturnData = Pinger.Receive(ref endPoint);
            // First 4 bytes is header, always should be 147
            // Next 4 bytes is server name length.
            // Next Unicode formated string of server name.
            // Next 4 bytes is Mod's version string length
            // Next UTF8 formated string of version.
            // Next 4 bytes after version string is current amout of players on server.
            // Next 4 bytes is max players slots on server.
            // Next 4 bytes is server information json string length.
            // Next Unicode formated string of server's information.


            int i = 0;
            int IntHeader = BitConverter.ToInt32(ReturnData, i);
            if (IntHeader == 147)
            {
                Console.WriteLine("Correct header!");
            } else
            {
                Console.WriteLine("Wrong header!");
                return;
            }
            i += 4;
            int ServerNameLength = BitConverter.ToInt32(ReturnData, i);
            i += 4;
            string ServerName = Encoding.Unicode.GetString(ReturnData, i, ServerNameLength);
            i += ServerNameLength;
            int ServerVersionStringLength = BitConverter.ToInt32(ReturnData, i);
            i += 4;
            string ServerVersion = Encoding.UTF8.GetString(ReturnData, i, ServerVersionStringLength);
            i += ServerVersionStringLength;
            int Players = BitConverter.ToInt32(ReturnData, i);
            i += 4;
            int PlayersMax = BitConverter.ToInt32(ReturnData, i);
            i += 4;
            int ServerConfigStringLength = BitConverter.ToInt32(ReturnData, i);
            i += 4;
            string ConfigString = Encoding.Unicode.GetString(ReturnData, i, ServerConfigStringLength);

            Console.WriteLine(ServerName+" version " + ServerVersion +" Players: " + Players + "/" + PlayersMax +" Server json:");
            Console.WriteLine(ConfigString);
            Pinger.Close();
        }