Whiteboard

Why it's ranked here

Agents now write more code than people can comfortably read, and this project treats review, not authoring, as the job that needs tooling. The repository backs the pitch with real infrastructure: a signed, notarized release pipeline for macOS and Windows, a published event-by-event telemetry contract enforced by an allowlist on the machine, and a structural diff engine built on difftastic's algorithm with a WebAssembly plugin runtime. Everything is MIT licensed. The case against is youth: the diff tool labels itself experimental, its plugin interface is declared unstable, and the app cannot yet edit files.

What's good

Privacy is documented in more detail than most desktop tools manage. Passive telemetry passes a local allowlist, never carries code, paths, repository names or prompts, and honors the standard do-not-track environment variable. The Microsoft telemetry inherited from the editor core is disabled, with a test enforcing it. Sharing uploads the write-up and the commits it is pinned to, not your source: recipients fetch code from GitHub with their own access, and a share can be revoked. The diff engine core needs no git, threads or terminal, which is why the same engine also runs as a client-side web page.

Tradeoffs

It is a viewer, not an editor: the project states files cannot be edited in it, browsing several repositories in one review is not well supported, and a shared review does not update for recipients after it is sent. Telemetry is on by default, and after a crash a local dump that can contain open source text uploads on next launch unless telemetry is off. Only macOS has auto-updating release channels; Windows installs do not update themselves. Building from source needs Node 24, pnpm 11, Python and a C++ toolchain. Hosted trace storage uses server-held encryption keys, so the operator can decrypt stored transcripts.

How to use it well

Built for a developer or lead who reviews large agent-written branches and wants the reasoning laid out before reading lines. Install the app, connect your agent from the welcome screen, and ask it to review your branch against current main; the project recommends a strong frontier model. For small diffs, skip the app and run diffr in the terminal, where it takes the same arguments as git diff, or inside Claude Code as a mod. Switch telemetry off in settings for sensitive code, and treat hosted trace upload as a separate decision, since transcripts can include source and prompts. It does not replace your editor or pull-request host.

Observed

License

MIT; the vendored editor fork keeps Microsoft's MIT license

Languages

TypeScript monorepo (pnpm) plus a Rust diff engine

Interfaces

Desktop app, CLI, MCP and API surfaces, terminal diff viewer, Claude Code mod

Packaging

Homebrew cask for the app; diffr via install script, Homebrew, crates.io or cargo-binstall

Platform support

macOS with auto-updating channels; Windows installers without an update feed; Linux packaging script

Telemetry

Anonymous telemetry on by default, opt-out via settings or DO_NOT_TRACK

Plugin system

WebAssembly component plugins via wasmtime, documented as not yet stable

Editing

Files cannot be edited in the app, per the README's known limitations