JayJay

JayJay is a native macOS and Linux GUI for Jujutsu, with reusable Rust libraries for diff and review tooling.

• macOS: native SwiftUI app.
• Linux: GPUI shell in beta. Its macOS build is for development.
• Rust libraries: diffing, review state, repository operations, and app bindings.

Install on macOS · Linux beta · Rust libraries · Discord · Contribute

JayJay macOS App

JayJay is a fast, keyboard-driven GUI for people who use jj every day.

Highlights

• DAG visualization with bookmarks, tags, conflicts, author avatars, relative time, and revset filters.
• Unified and side-by-side diffs with syntax highlighting, word-level changes, context collapsing, rename detection, and image/SVG/Markdown/HTML previews.
• Interdiff for PR-style revision comparison, file annotate, file history, and change evolution (jj evolog).
• Diff edit mode: select files, hunks, or line ranges across a change.
• Persistent file and hunk review marks that preserve matching reviewed hunks across edits and rebases, with line-anchored review notes.
• Conflict resolution with whole-file or per-hunk choices, syntax-aware -/+ gutters, a raw marker editor, and an explicit external jj resolve --tool handoff.
• Common jj operations from the app: new, edit, describe, squash, abandon, split, duplicate, merge, absorb, back out, Git push/fetch, and undo.
• Bookmark Manager, drag-to-move bookmarks and working copy, GitHub/GitLab/Codeberg/Cursor Origin PR actions, stacked PRs/MRs, and command palette.
• AI commit-message fallback chain: Codex CLI, Claude CLI, then Apple Intelligence.
• External editor and terminal integration, multi-window support, recent repos, Dock menu, and CLI launcher.
• jayjay config prints the paste-ready jj diff/edit/merge tool definition, also available from Settings → CLI.

See the full feature guide for screenshots and workflows.

Install

Requirements: macOS 26 or later.

Homebrew:

brew install --cask hewigovens/tap/jayjay

Direct download: grab the latest .zip from GitHub Releases, unzip, and move JayJay to Applications.

JayJay checks for updates automatically through Sparkle. You can also run JayJay -> Check for Updates.

Feedback

Join the JayJay Discord community to ask questions, share workflows, and give feedback.

Choose Help -> Send Feedback in JayJay to email us.

Build the app

Follow Contributing to install prerequisites, then:

just run          # Build and launch the SwiftUI macOS app
just install-cli  # Install the jayjay launcher to ~/.local/bin
jayjay .          # Open the current repo

Rust Libraries

The Rust workspace keeps diff rendering, review state, and shared domain types independent of jj-lib.

Rule of thumb: jj-lib belongs in jayjay-core. Diff rendering, review state, and shared domain types stay below that boundary so they can be reused without embedding jj's repo model.

jj-diff

jj-diff is the most reusable standalone library in the repo. It has zero dependency on jj-lib.

[dependencies]
jj-diff = { git = "https://github.com/hewigovens/jayjay" }

use jj_diff::{collapse_context_with_mapping, compute_file_diff};

let diff = compute_file_diff("main.rs", &old_content, &new_content, false);
let collapsed = collapse_context_with_mapping(&diff);

for line in &collapsed.diff.lines {
    // render line.style and line.spans in your UI
}

Features:

• Histogram line diff via similar.
• Word-level highlighting within changed lines.
• tree-sitter syntax highlighting for common source formats.
• Context collapsing with display-to-full line index mapping.
• Side-by-side row building for two-column renderers.
• Placeholder detection for Git LFS, submodules, and binary content.

See crates/jj-diff/README.md for the full API.

Docs

• User Guide - shipped features and workflows (docs/guide.html).
• Issues - planned work and known gaps.
• Contributing - setup, development checks, testing, and pull request policy.
• Agent instructions - repository constraints and focused engineering guides.
• DeepWiki - indexed codebase reference.
• FAQ - install, licensing, platform support, and common feature questions.
• Blog - notes on Jujutsu, collaboration, and the tools around them.

GPUI Shell (Beta)

There is also a GPUI shell, now in beta, whose current parity target is Linux. Its macOS build is for development; the released macOS product remains the SwiftUI app. Remaining work is tracked in the GPUI Beta checklist.

Linux builds ship with every release: download the AppImage for your architecture from the release page, or on Arch Linux install the attached jayjay-appimage package with pacman -U. Stable releases are also in a signed pacman repo — trust https://pkgs.hewig.dev/arch/jayjay-packages.asc, point a [jayjay] section in /etc/pacman.conf at https://pkgs.hewig.dev/arch/$arch, then sudo pacman -Syu jayjay-appimage; the guide has the full block.

just gpui           # Build and launch the GPUI shell
just gpui-appimage  # Build the Linux AppImage

Keyboard Shortcuts

License

• Rust crates (crates/): Apache-2.0
• App shells and everything else (shell/, docs, packaging): BSL 1.1 - free to use, modify, and redistribute; paid app store distribution requires permission. Converts to Apache-2.0 on 2030-03-23.