This document provides an overview of Abide, a static checker tool for Scala based on type-checked ASTs. It has the goals of unifying existing rule-based approaches, making it easy to write and use rules, and providing reasonable performance and good integrations. Rules are decoupled from the tool and can come from core, extra, or project-specific packages. The document gives examples of core rules and rules for Akka and describes Abide's architecture, use, anatomy including traversers, directives, and how rules are coded. It encourages contributing rules to help the value of the tool.