Legend Apps

Legend Apps is a collection of focused, local-first apps for working with code, documents, and media. The apps are designed around files you control, native platform behavior, and responsive handling of large libraries and documents.

Apps

Legend Diff

Legend Diff is a native macOS viewer for reviewing changes across repositories, files, patches, GitHub pull requests, and commits. It can:

• compare a Git working tree, branches, tags, commits, or other refs
• compare two files or open existing .diff and .patch files
• load GitHub pull request and commit URLs
• browse changed files, search across a diff, and switch between unified and block-oriented views
• detect merge conflicts, choose ours, theirs, or both for each conflict, and save the resolved file

Files, folders, and URLs can be opened through dialogs, drag and drop, paste, launch arguments, or the optional ldiff command-line helper. Appearance, syntax highlighting, context, and window restoration are configurable. Legend Diff requires macOS 14 or later. Local repository comparisons require Git.

Legend Markdown

Legend Markdown is a local-first block Markdown editor for macOS. It edits the Markdown file directly while presenting inactive blocks as rendered content and turning the active block into an editor.

It supports new and existing Markdown documents, Save and Save As, optional autosave, recent documents, external file changes, undo and redo, keyboard navigation, and native formatting menus and toolbars. Themes, typography, content width, document density, toolbar placement, toolbar contents, and hotkeys are customizable. The current app supports one document window at a time and does not expose a separate raw-source mode.

Legend Music

Legend Music is a local music player built around folders and audio files you own. It scans one or more library folders, reads track metadata and artwork, and lets you browse by library, album, artist, or playlist.

Playback includes a persistent queue, next and previous controls, shuffle, repeat, volume, seeking, media keys, and configurable global hotkeys. Local .m3u playlists can be created, edited, imported, and exported. The macOS app also supports drag and drop, a configurable now-playing overlay, multiple utility windows, themes, and customizable playback controls. iOS and Android development targets exist, but the full experience is currently macOS-first.

Legend Code

Legend Code is a read-only TypeScript and TSX viewer for macOS. It uses native parsing, incremental syntax highlighting, and virtualized rendering to keep large source files responsive.

Files can be opened from Finder, the native Open dialog, launch arguments, or recent documents. The viewer reloads files after external changes and provides font, size, syntax-theme, and highlighting settings. Legend Code intentionally does not modify source files.

Legend Chat History

Legend Chat History is a macOS demo for browsing recent local Codex and Claude transcripts. It discovers sessions on the Mac, groups them by provider, and renders the selected conversation in a virtualized transcript view.

The composer is an interaction and performance demo: it streams a simulated response in memory, sends nothing to a model, and does not persist the generated messages.

Availability

Legend Diff is currently packaged for Apple silicon and Intel Macs through the repository's GitHub Releases. The repository is private, so public downloads are not yet available. Other app statuses are marked above.

For developers and contributors

This repository is a Bun workspace built around React Native and a reusable native host under shell/. Each app supplies its JavaScript entrypoint, identity, supported platforms, native-module graph, and release metadata through apps/<app>/app.manifest.ts.

Developer integration app

• Legend Test Kitchen Sink is the integration harness for shared packages across macOS, iOS, and Android.

Requirements

• Bun for workspace installation, scripts, and tests
• Xcode and CocoaPods for macOS and iOS native builds
• Android Studio and an Android SDK for Android builds

Install workspace dependencies from the repository root:

bun install

Run an app

All app commands use the same shape:

bun run <app> <action> [platform] [options]

The platform defaults to macos. For example, start Music's Metro server and run its macOS app from separate terminals:

bun run music start macos
bun run music run macos

Common actions:

Action	Purpose
start	Start Metro for macOS or the Expo dev server for iOS and Android
run	Prepare native configuration, build, and launch a development app
open	Open an already-built macOS development app
verify	Verify generated configuration, identity, and native package linking
pods	Install CocoaPods for a macOS or iOS app
prebuild	Generate the Expo iOS or Android native project
build	Create a release build
package	Package, sign, notarize, and generate appcasts for a macOS release
githubrelease	Publish an already-packaged macOS build as a GitHub release

Only use actions and platforms supported by the selected app. Running bun run <app> without an action prints the complete command help. Dedicated Metro ports in scripts/lib/apps.ts allow multiple app servers to run without colliding.

When an app manifest or native package link changes, refresh CocoaPods before rebuilding macOS:

bun run <app> pods macos

For iOS or Android, generate the native project before the first run when it is not already present:

bun run music prebuild ios
bun run music run ios

Validate changes

The baseline repository checks are:

bun run typecheck
bun run verify:all
bun run verify:react-compiler

Focused suites cover the main app and package workflows:

bun run test:music --runInBand
bun run test:diff:fast
bun run test:markdown-editing

Runtime E2E scripts are separate because they build or control apps:

bun run test:diff-e2e
bun run test:markdown-e2e

Workspace layout

• apps/ contains app manifests, package metadata, UI, state, and app-specific tests.
• packages/ contains shared TypeScript libraries and React Native native modules.
• shell/ is the reusable Expo and React Native host and owns generated native projects.
• scripts/ contains app selection, configuration generation, verification, build, package, and release tooling.
• patches/ contains Bun patchedDependencies applied during installation.
• themes/ contains shared display, syntax, and document themes.
• updates/ contains architecture-specific Sparkle feeds for macOS releases.

Generated per-app native workspaces and configuration live under shell/.legend/ and are build output rather than app source.

Release builds

Release builds are opt-in and are not part of the normal iteration loop:

bun run diff build macos
bun run diff package macos all
bun run diff githubrelease macos all

macOS packaging supports architecture-specific or combined output and requires the signing, notarization, Sparkle, and GitHub credentials expected by the release scripts. App versions come from apps/<app>/package.json; build and Sparkle metadata come from the app manifest. See RELEASING.md for the complete release workflow.