Rules engines on the JVM in 2026
Drools is no longer the only game in town. A look at Easy Rules, RuleBook, and when you should reach for a rules engine at all.
Tagged rules
5 posts about rules.
Using the KIE Workbench API to create a project
The KIE Workbench REST API lets you automate project setup in a fresh container — useful when VirtualBox keeps changing your IP address.
A minimal Spring Boot Drools web service
Just the essentials: a Spring Boot application exposing a Drools rules engine as an HTTP API, nothing more.
A web service powered by Spring and Drools
A reference project wiring Spring and Drools without the heavyweight KIE integration — hand-cranked and straightforward.
A BigDecimal accumulator for Drools
Drools's built-in sum accumulator silently converts BigDecimals to doubles. A custom accumulator to fix that before it corrupts your financial calculations.