What is lgtm?

lgtm is a fast, native code review app written in Rust, built with a UI toolkit called gpui. It is designed to make reviewing pull requests feel quick and responsive rather than waiting on a web page to load. The author is upfront that the whole project was written through AI assisted vibe coding and that they personally have not read the underlying code. To review pull requests on GitHub directly, you need the GitHub CLI installed and signed in first. Without that, the app still works, but only for reviewing code changes on your own local machine rather than pulling requests from GitHub. The easiest way to install it is to download a prebuilt disk image for Apple Silicon Macs from the latest release, then drag the app into the Applications folder. Since the app is not signed, macOS will show a warning the first time it opens, which can be cleared by right clicking the app and choosing Open, or by removing the quarantine flag from the terminal. Building it from source is also possible with Cargo, though this requires Xcode installed, since the build depends on Apple's Metal shader compiler. The app supports both unified and side by side diff views, syntax highlighting for eighteen languages through tree-sitter, word level highlighting inside changed lines, a sidebar with a file tree for browsing multiple files at once, a command palette for quickly jumping to a pull request or folder, and a minimap for navigating long files. It can read and post inline comments directly on GitHub, and lets you submit a full review as an approval, a request for changes, or a plain comment. A full set of keyboard shortcuts covers switching views, moving between files and diff hunks, toggling the sidebar or minimap, and even opening a chat with Claude Code from inside the app. The README lists LSP support and AI generated inline review notes as features still to come.