jjdiff

A fast, minimal desktop app for reviewing and landing changes in Jujutsu colocated repos. Tauri 2 + Rust + Lit. jj-native from day one: no staging axis, change-id identity, stack review.

Why jj-native

• No staging axis. The working copy is a commit. The loop is edit → review @ → describe → new; partial commits are squash and split, not git add -p.
• Change ids are identity. Viewed flags, review comments and walkthroughs key on the change id, so they survive describe, squash and rebases. Structurally impossible in git; trivial in jj.
• Review the stack, not just a diff. A sidebar over trunk()..@, per-change review, "what changed since I last reviewed" interdiffs, and moving files or hunks between changes.

What it does

Review. Live working-copy diff (the filesystem vs @-, never a snapshot) or any revset; split or unified; word-level intra-line spans; whitespace toggle; expand-context; images side by side and rendered markdown. Virtualized and keyboard-first — j/k files, n/p hunks, v viewed, ⌘F to find. Press ? for the full list.

Act. Describe (with generated messages), new, edit, squash and split by file or by hunk, absorb, rebase from a picker or by drag, backout, duplicate, abandon, restore. Bookmarks, fetch, push, ahead/behind. The operation log is a first-class tab and every mutation reports what it did with an Undo that reverts exactly that operation. Conflicts are navigable by region and resolvable in-app.

Walkthroughs. One click turns a change into a guided review: an agent CLI (claude, codex, opencode or pi) writes a reading order over the diff plus an overview document — impacted systems, changed contracts, new state and effects — with steps that filter the diff to their hunks. Agents can also author walkthroughs headlessly via --print-hunks and --walkthrough-file.

Pull requests. jjdiff pr 75 fetches the head and reviews it like any other change: reviewers, merge state and CI checks above the diff, the conversation alongside it, and the inline comments you accumulated submitted back as the review. Driven by gh — jjdiff never handles tokens, and your own branch's PR surfaces itself when its checks change. GitHub only.

And the rest. jj workspaces (create one for a change without leaving the tree you're in), one window per repo, nineteen named themes plus light/dark, a command bar mirrored into the native menu, open-in-editor, and a CLI that is the same binary as the app.

Install

Prebuilt, signed and notarized macOS builds (universal: Apple Silicon and Intel) are on the releases page. Linux builds from source below — CI keeps that compile green. Windows is untested.

From source, with Rust (stable), Node 20+, pnpm and jj ≥ 0.33:

pnpm install
pnpm tauri build

Either way, put jjdiff on PATH with the in-app menu item or jjdiff --install-terminal-helper.

Usage

jjdiff                     # the repo you're in
jjdiff -R /path/to/repo    # another repo
jjdiff 'trunk()..@-'       # open on a revset
jjdiff -w                  # ... and generate a walkthrough
jjdiff pr 75               # review a GitHub pull request
jjdiff --diff @            # headless: the structured diff as JSON
jjdiff --print-hunks       # headless: hunk ids, for agents

Configuration

~/.config/jjdiff/config.toml, same convention as jj itself:

[ui]
diff-style = "split"    # or "unified"
theme = "system"        # "light" / "dark" / any palette in the theme picker

[keymap]
command-bar = "Mod+k"   # Mod is Cmd on macOS, Ctrl elsewhere

[editor]
# Placeholders: {file} (absolute), {line}, {repo}. No shell — split on spaces.
command = "zed {file}:{line}"

Settings (⌘,) writes to this file one key at a time; your comments and key order survive.

Development

pnpm install
pnpm tauri dev                          # app against the cwd repo
pnpm tauri dev -- -- -R /path/to/repo   # against another repo
pnpm dev                                # UI only, in a browser, on mock data

cargo test --workspace
cargo clippy --workspace --all-targets -- -D warnings
pnpm build                              # typecheck + bundle the UI

pnpm build must precede any cargo command in a clean checkout. pnpm release bumps the version, updates the changelog, tags and pushes; the tag triggers the signed release build. See CLAUDE.md for the rules of the codebase and PLAN.md for how it got here.

Layout

• crates/vcs — the only place that shells out to jj (read/mutate discipline, JSONL templates)
• crates/diff — patch parsing and filesystem-vs-tree diffing
• crates/watch — op-head and working-copy watchers (change detection without polling)
• src-tauri — app shell, IPC commands, headless CLI
• ui — Lit frontend (light-DOM code pane)

License

MIT