Differ

A local-first, AI-native Git and GitHub review desktop app.

Differ is a focused desktop surface for reviewing local changes and GitHub PRs, leaving comments, extracting high-quality context, and handing that context to AI coding agents like Codex, Cursor, or Claude Code.

Stack

• Electron (desktop shell)
• React + Tailwind + Radix primitives (renderer)
• SQLite via better-sqlite3 (local storage)
• Native git CLI through a typed IPC bridge (the renderer never spawns commands directly)
• GitHub REST API via @octokit/rest

Dev

npm install
npm run dev

npm run dev starts the Vite renderer on http://localhost:5173 and an Electron process pointed at it.

Build

npm run build
npm start

npm run build produces dist/electron/*.js (main + preload) and dist/renderer/* (the React app). npm start launches Electron against the built output.

GitHub OAuth (optional, for "Sign in with GitHub")

Differ supports the GitHub OAuth Device Flow so users can sign in with one click and browse / clone their personal, private, and organization repositories.

Because Differ is open source, the client_id for the OAuth App is not hardcoded — each build supplies its own. To enable OAuth sign-in:

1. Visit https://github.com/settings/developers → New OAuth App

2. Fill in any homepage/callback URL (callback isn't used for device flow).

3. After creating the app, open its settings and enable Device Flow.

4. Copy the Client ID.

5. Copy .env.example to .env (gitignored) and paste the Client ID:

   cp .env.example .env
   # then edit .env and set:
   #   DIFFER_GITHUB_OAUTH_CLIENT_ID=Iv1.xxxxxxxxxxxxxxxx
   # optional — override the requested scopes (default: repo read:org read:user)
   #   DIFFER_GITHUB_OAUTH_SCOPES=repo read:org read:user

   The Electron main process loads .env automatically at startup.

The Client ID is public information by design — it's safe to ship in built artifacts. If DIFFER_GITHUB_OAUTH_CLIENT_ID is unset, the "Sign in with GitHub" button is disabled and users can still sign in by pasting a personal access token.