The pi-diff-review plugin adds a `/diff-review` command to the pi coding agent that opens a native review window for examining git changes. The window allows users to switch between viewing changes in the working tree (git diff), the last commit, a specific commit, or all files. Users can add inline comments and an overall note, which are then formatted into a prompt and inserted into the pi editor. The plugin consists of a backend written in TypeScript that interacts with git and the pi extension, and a frontend built with HTML, CSS, and Monaco Editor that runs in a Glimpse window. The backend cleanly separates concerns: git data collection (src/git.ts), command handling and messaging (src/index.ts), prompt composition (src/prompt.ts), and HTML generation (src/ui.ts). The frontend provides an interactive diff viewer with commenting capabilities. A notable reusable component is the git data gathering logic in src/git.ts, which isolates the complexity of interacting with git to collect file status across multiple scopes. This module could be extracted for use in other git-based tools with minimal adaptation, primarily by replacing the pi ExtensionAPI-dependent command execution with a generic interface.