pi-diff

Local, full-screen branch diff browser, built as a Pi extension. Runs inside your existing Pi session — no forge, no network call, no mouse required.

/diff           # compare current branch against auto-detected base (origin/HEAD, else main/master)
/diff develop   # compare against an explicit base branch
/diff local     # compare HEAD with staged, unstaged, and untracked working-tree changes

Branch mode uses git diff <base>...HEAD (the same merge-base semantics as GitHub/GitLab PR/MR views). Local mode compares the final working tree against HEAD, combining staged and unstaged edits and adding non-ignored untracked files as new-file diffs.

What it does

• Two-pane layout: file tree on the left (status, +/-, viewed marker), diff on the right.
• Syntax-highlighted diff content powered by @shikijs/cli — the same Shiki ANSI engine used by pi-claude-style-tools. It selects github-dark/github-light from Pi's active surface, caches highlighted old/new streams so multiline grammar state remains correct, and normalizes low-contrast tokens over tinted diff rows.
• Fast keyboard scrolling: full page, half page, hunk jumps, and top/bottom jumps — no need to walk large diffs one line at a time.
• Viewed tracking that survives restarts. Marking a file viewed is keyed on that file's diff content hash and persisted in the session (branch-aware, like Pi's built-in Todo list). If you amend/rebase and a file's diff actually changes, it's automatically un-marked.
• Draft comments anchored to a specific line. r writes them all out to .pi-diff/<branch>.md — easy to paste into a PR/MR description or hand to a reviewer.

Keybindings

Key	Tree focus	Diff focus
↑/↓ or j/k	move file selection	move line cursor
→ / l / Tab	switch to diff pane	—
← / h / Tab	—	switch to file tree
PageDown / PageUp	move one page	move one page
d / i	move half a page down / up	move half a page down / up
] / [	—	next/previous hunk
g / G	first/last file	first/last changed line
Space	toggle viewed	toggle viewed (current file)
Enter	toggle viewed + advance	draft a comment at cursor
c	—	draft a comment at cursor
n / N	jump to next/previous unviewed file	same
r	write drafted comments to .pi-diff/<branch>.md	same
q / Esc	close panel	same

Known limitations (v0.2)

• /diff local shows the final working-tree state rather than separate staged and unstaged snapshots. Ignored files are intentionally excluded.
• No mouse support — deliberate. Pi's TUI component API doesn't expose a mouse event layer, and the rest of Pi is keyboard-driven; fighting that would cost more than it's worth.
• Comments are local notes, not posted anywhere automatically — there's no forge in the loop.

Local development

npm install            # installs the pinned @shikijs/cli renderer dependency
npm test               # parser + git/local mode + tree + Shiki theme + panel tests
pi -e ./index.ts        # load this extension for a single session, from any git repo

Install

pi install ~/code/pi-diff                              # current local checkout, all sessions
pi install -l ~/code/pi-diff                           # current local checkout, this project only
pi install git:git@github.com:j-joker/pi-diffffff.git # private GitHub repository (SSH access required)

From npm after publication: pi install npm:pi-diffffff.