DiffGuardian

Engineers, product managers and anyone else who has to know what a fleet of coding agents is shipping are the users DiffGuardian is made for. It is a desktop application for macOS, Windows and Linux that explains code changes aloud or in writing.

Talking to a pull request

A user holds the space bar and asks what a pull request does. DiffGuardian walks through the features it ships, what each one changes and what it touches, while the code being explained scrolls into view and is highlighted. Follow-up questions can be asked at any point, and typing is available for those who prefer it.

Talking to the whole codebase

The app indexes a repository into a code knowledge graph. Asked how authentication works or where a webhook is verified, it answers aloud while a live visual of the flow builds on screen from the call graph. It can also produce a graph of the files and modules a change touches from the diff alone.

Reading at your own pace

For people who prefer reading, a feature called Trace It turns even a very large pull request into a guided tour, one feature at a time, explained in plain English.

Keys, models and privacy

Users can bring their own keys from Anthropic, OpenAI, Gemini or OpenRouter, or point it at local models. Voice runs on OpenAI, ElevenLabs or the system voice. The maker says code does not pass through its servers, and notes that model usage is paid separately to the chosen provider.

Plans

The free plan allows one connected public repository and five AI reviews each month, using local models only. Pro and Team plans are listed, with Team requiring a minimum of 3 seats, and an Enterprise tier with single sign-on is listed as not yet available. The operating company and its location are not stated, and the maker showed the app to Hacker News readers on 8 October 2026.