DiffGuardian

DiffGuardian is a desktop app running on macOS, Windows and Linux. It helps people understand code changes, including those written by AI agents. Users can ask about a pull request or the whole repository and hear a spoken answer while the relevant code is highlighted. A separate view maps which files and modules a change reaches, drawn from the diff alone.

Main features

• Spoken walkthrough: hold a key to ask about a pull request and hear it explained feature by feature, with the code scrolling into view.
• Written walkthrough: the same explanation as text, read at the reader's own pace.
• Codebase questions: ask a question about the whole repository and see the answer as a live graph of the flow.
• Change map: a graph of the files and modules that a change touches, built from the diff.
• Model choice: runs on the user's own keys for several AI providers, or on local models. The maker says code never passes through its servers.

Customers and markets

Built for engineers, product managers and anyone building software, including teams that buy plans for several people.

Key facts

• Platforms: macOS, Windows and Linux
• Presented: 8 October 2026, on Hacker News by the maker
• Voice: the system voice, or an external voice service the user connects with a key
• Enterprise sign-in: single sign-on is marked as coming soon