This is a stock-flow consistent model, namely the simplest (SIM) model with government money. I have added imports and exports and an exchange rate which has an influence on consumption demand via real disposable income and real foreign demand.

Godley/Lavoie (2006), chapter 3

(I had to change the equation for consumption demand. The disposable income now enters with a time lag of one period. Otherwise the model would be recursive and would not work in Insight Maker. Thanks to Gene for support.)