How do I see what a PR actually affects?

DiffGuardian draws a dependency graph for every pull request, built straight from the diff. It is a heuristic, not an AI feature: no model call decides what is connected to what; the edges come from the diff's changed files and their imports, plus callers and implicit links found in a local checkout when you give it one.

#What the graph shows from the diff alone

Without a local checkout, the graph is built entirely from the diff: the changed files, and the modules those files import. Nothing beyond the diff itself is used to draw it, and no AI is involved in deciding the edges.

#What a local checkout adds

Point DiffGuardian at a local checkout of the repository and the graph adds three more kinds of edge: upstream callers appear as extra nodes flowing into the edited file; implicit API edges and channel edges are drawn dashed.

• Upstream callers — code that calls into an edited file, added as extra nodes flowing in from elsewhere in the repository.
• Implicit API edges — an endpoint connected to its callers, even where nothing in the diff links them directly. Drawn dashed.
• Channel edges — an emitter connected to its listener. Drawn dashed.

#Reading the graph

Click a node to pin its flow through the graph and open the per-hunk overviews for the changed files inside it.

DiffGuardian is a desktop app for macOS, Windows and Linux, and works with pull requests on GitHub, GitLab and Bitbucket.

#Limits

• The graph is a heuristic built from the diff and, optionally, a local checkout — it is not an AI-generated summary of impact.
• Upstream callers, implicit API edges and channel edges only appear with a local checkout. Without one, the graph shows diff-derived edges only.