# How to define an event?

PREREQUISITE

Define a stream module

Open the respective .kstream file
Define the event using keyword event.

For example to define an event LotteryCreated with lotteryName & amount as the event data, define the following in LotteryStream.kstream file
```
event LotteryCreated(lotteryName:String,amount:Int)
```

Note: Event names are generally in past-tense