# 11 — Desktop App (Kotlin + Compose Multiplatform)

The desktop app is **the Android app, tweaked for a big screen**. It reuses the
entire `app/shared` module (protocol, network, repositories, state, most UI) and
only adds desktop platform services + a wider default layout.

## 11.1 What's shared vs desktop-specific

| Layer | Shared (commonMain) | Desktop-specific (desktopMain) |
|---|---|---|
| Protocol / WS client | ✅ | — |
| Repositories / state | ✅ | — |
| Most Compose UI | ✅ | layout tweaks, keyboard shortcuts |
| Push | — | **tray icon + OS notifications** (no FCM) |
| Media playback | `MediaPlayer` interface | **desktop player** actual |
| File picker | `MediaPicker` interface | **desktop file dialog** actual |
| Window | — | resizable window, always-on-top, global hotkey |
| Secure store | `SecureStore` interface | keyring / encrypted file actual |

## 11.2 `desktopMain` platform services

- **Push → tray + OS notifications.** Desktop is assumed reachable (persistent
  WS), so no FCM. A **system tray icon** shows connection state + unread count;
  OS notifications (Java Desktop / `SystemTray` + a cross-platform notifier)
  fire for background chats / approvals / cron. Clicking focuses the window and
  deep-links to the chat.
- **Media playback → `MediaPlayer` actual.** ExoPlayer is Android-only. Desktop
  uses a `libmpv`/`mpv`-backed Compose surface for video (and audio), with a
  WebView-based fallback if `mpv` isn't available. Same `MediaPlayer` interface
  the Android `ExoPlayer` actual implements, so UI code is identical.
- **File picker → `MediaPicker` actual.** A native file dialog (Compose
  Desktop `FileChooser` / AWT `JFileChooser`) returning local file paths, then
  the same `media.upload` chunked path.
- **Window.** Resizable, remembers size/position, optional always-on-top, a
  global hotkey to focus/show. Minimize-to-tray option.
- **Secure store → `SecureStore` actual.** OS keychain (macOS Keychain, Linux
  Secret Service / encrypted file, Windows Credential Manager) or an encrypted
  file for the token + pinned cert.

## 11.3 Layout (big-screen tweaks)

- **Two-pane is the default** (persistent left channel rail + chat), since there
  is width. Single-pane still available via the same toggle.
- **Wider chat column** with comfortable max line length; optional **third
  pane** (inspector: session info, model, tokens, tool detail, channel settings).
- **Larger type scale** and spacing for desktop; hover states; mouse + keyboard
  first.
- **Keyboard shortcuts:**
  - `/` focus the composer and open the command menu.
  - `Ctrl/Cmd+K` command palette (all slash commands + actions).
  - `Ctrl/Cmd+N` new channel; `Ctrl/Cmd+T` new thread.
  - `Ctrl/Cmd+F` search (with the all/this-chat scope toggle).
  - `↑/↓` navigate channel list; `Enter` open.
  - `Esc` close sheet/dialog (one cancel gesture does exactly one thing).
- **Multi-window (stretch):** open a channel in a separate window / pop-out.

## 11.4 Distribution

- **Compose Desktop** → native binaries via **jpackage** (or a plain app image):
  Linux (.deb/.AppImage), macOS (.dmg), Windows (.msi/.exe).
- Bundles the JRE. Auto-update is a stretch goal (v1: manual download).
- The desktop app connects to the **same** gateway WS server as the phone (the
  user's home server / Tailscale). It does **not** spawn its own backend (unlike
  hermes's existing Electron desktop, which spawns `hermes serve`) — our
  desktop is a pure client of the messaging gateway, matching the Android app.

## 11.5 Parity checklist (same functionality as Android)

- [ ] Streaming, reasoning block, tool cards (3-level verbosity), commentary.
- [ ] Channels + threads + new channel + cron target.
- [ ] Search (all / this-chat).
- [ ] Media attach + live playback (via desktop player).
- [ ] Slash command menu + autocomplete + interactive pickers.
- [ ] Push (tray + OS notifications) + outbox/sync.
- [ ] Pairing/Connect screen (URL + token, WSS cert pin).