CodeRabbit Custom Rules: Review Instructions Guide

Every team writes code differently. Your naming conventions, architectural patterns, testing standards, and security requirements are specific to your project - and a code review tool that cannot be taught those conventions is only half useful. CodeRabbit solves this with its .coderabbit.yaml configuration file, which lets you write custom review instructions in plain English and apply them automatically to every pull request. The real power of CodeRabbit custom rules is not just in setting global preferences. It is in the ability to apply different review standards to different parts of your codebase, configure the tone and depth of feedback, control which files get reviewed and which get skipped, and encode your team's hard-won knowledge about what "good code" looks like in your specific project. This guide walks through all of it - from basic configuration to production-ready examples for React frontends, Python APIs, and microservice architectures. Understanding the .coderabbit.yam