Grab a socket.io library for your language of choice.

Connect to http://scratch.andrewl.in:4321

Emit a `login` message with `userId` of `brain` and a `sessionId`.

Handle `message` events. They have the following format:
```
{
  userId: string;
  sessionId: string;
  payload: {
    type: PayloadType;
    keyCode: string;
    x: number;
    y: number;
    draw: DrawCommand[];
  };
}
```

Payload Types are:
```
  KEYDOWN = 0;
  KEYUP = 1;
  MOUSEDOWN = 2;
  MOUSEMOVE = 3;
  MOUSEUP = 4;
  LOGIN = 100;
  DRAW = 1000;
```

DrawCommand has the following format:
```
{
  type: 'r' | 't' | 'l';  // r is for a rectangle, t for text, l for line
  x: number;
  y: number;
  color: string;
  w: number;              // only used for rectangles
  h: number;              // only used for rectangles
  xEnd: number;           // only used for lines
  yEnd: number;           // only used for lines
  text: string;           // only used for text
}
```