Diffsmith Brings Inline AI-Agent Code Review to macOS

Summary

Diffsmith is a native macOS application for reviewing local Git changes and commits produced by an existing AI coding agent. It can compare working-tree changes, staged changes, commits, commit ranges, or branches, and presents modified, added, deleted, renamed, and untracked files with syntax-highlighted inline or side-by-side diffs. Reviewers can attach comments to exact lines, manage them in a persistent sidebar, and keep comments whose code changed in a separate Past Comments view. A one-click action converts comments and code context into an AI-ready prompt, with customizable templates and support for copying feedback from one or several repositories. An optional loopback-only MCP server lets a coding agent read and reply to comments inside the app; it is disabled by default. Recent versions add Walkthroughs, allowing an agent to create a numbered tour of code changes, plus image-diff comparison modes and broader commit review. Diffsmith is sold as a one-time purchase for $5.99, requires macOS 15 or later, and is listed as 4.8 MB. The developer says the app is sandboxed, collects no data, makes no outbound network calls, and keeps repositories and comments on the Mac except for the optional local agent connection.