Sources

Prchum reviews four kinds of source in the same window.

Patch files

Open a .diff/.patch file (File → Open…, drag onto the app, or the command line). Drafts key on the file's absolute path, so reviewing the same file again resumes the same notes.

Local git comparisons

File → Review Git Repository… picks a checkout and a comparison:

• Working tree vs HEAD — what git diff shows.
• Staged (index) vs HEAD — what git diff --cached shows.
• Against a base ref — base...HEAD, the merge-base comparison.

Each comparison keeps its own draft, so notes on the staged changes never mix with notes against main.

Pull requests

A URL, owner/repo#N, or a bare number (repository inferred from the current directory's origin). Prchum fetches the host's canonical diff, so comment positions always match what the forge shows, plus the existing review threads (◆ markers — ⌘R replies) and the pull request's metadata (⌘I). See Forges for hosts and authentication.

If the head moves between sessions, saved drafts re-anchor by their captured context: an exact match keeps its place, a unique text match follows the code, and anything ambiguous is orphaned — kept, marked, and never submitted. Guessing would put a note on the wrong line.

The review-exchange format

Prchum reads and writes leanreview's *.review.json format (version 1), detected by content, never by filename. An LLM writes its review into a self-contained document; you triage it in Prchum — dismiss, edit, reply — and every change rewrites the file in place, so quitting leaves the conversation current for the model's next round. Unchanged documents round-trip byte-identically, so the two clients interoperate on the same files.