# Sample Codes

{% embed url="<https://github.com/Defi-Board-Options-Exchange/java-dboe-labs>" %}

### Java-based smart contract (auto-generated by web3j):&#x20;

{% embed url="<https://github.com/Defi-Board-Options-Exchange/java-dboe-labs/tree/master/dboe-web3j-common/src/main/java/com/ngontro86/dboe/web3j>" %}

### POC Market making Program:&#x20;

{% embed url="<https://github.com/Defi-Board-Options-Exchange/java-dboe-labs/tree/master/dboe-market-making>" %}

* Pull live prices from external venues.
* Calculate greek risk given a list of holder addresses.
* Hedging out the risk using futures on an external venue (e.g. Binance).
* Submit two sided quotes on DBOE market.