CodeRabbit is an AI-powered code review platform that acts as an automated senior reviewer on every pull request, catching bugs, security issues, and design problems that humans often miss. It posts line-by-line inline comments, generates a TL;DR summary of each change with architectural sequence diagrams, and offers a one-click 'Fix with AI' button to apply suggested corrections. Rather than reviewing diffs in isolation, CodeRabbit builds whole-codebase awareness through its Codegraph analysis and pulls in external context from MCP servers, Jira, Linear, and the web. Teams customize it with YAML-based coding guidelines plus path and AST-based rules, and the AI learns from natural-language feedback over time. Beyond reviews, it generates unit tests with coverage analysis, auto-writes docstrings, runs 40+ integrated linters and SAST security scanners, and enforces custom pre-merge quality checks. CodeRabbit works inside pull requests on GitHub, GitLab, Azure DevOps, and Bitbucket, as well as a free IDE extension for VS Code, Cursor, and Windsurf and a CLI. Now the most installed AI app on GitHub, it serves 15,000+ customers across millions of repositories.