dsh-multiview — split view for DeepSeek Harness

Two to four real conversations side by side in one window. Every pane is the shipped Chat: composer, streaming, tool cards, approval cards, ask_user_question, attachments, slash commands, stop/queue.

The goal is not "a working split view" — it is to read as a feature the app ships with: no title-bar takeover, no layout hijacking, no monkey-patching of private extension points.

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Install

Add the bundle from Plugins → Add in DSH Desktop (or let a maintainer run plugin_manager install_bundle), then quit and reopen DeepSeek Harness so the client bundle loads again.

A "Split" icon appears in the left panel list; click it to turn the central column into the stage, click again to return to the native conversation.

• Requires DSH >=0.2.1-rc.5 <0.2.2-0 || >=0.2.2-rc.1 <0.3.0 (engines.dsh).
• Uninstall: disable/remove on the Plugins page, restart. The only residue is the localStorage['dsh.multiview.v1'] layout key (the stage's "Reset" clears it).

Using it

Action	How
Open / close	The "Split" icon in the sidebar panel list
2 / 3 / 4 panes	The 2 3 4 chips in the stage bar
Resize	Drag the divider between panes
Swap two panes	Drag a pane title onto another pane
Maximize / restore	The ⤢ button in the pane header; the stage bar shows "Restore"
Bind an empty pane	Search and pick a session right inside the pane
Open in the native view	The ↗ button: hands the session back to the real conversation (the right sidebar's file preview and diff review only exist there)
Remove a pane	The ✕ button; a bound pane goes back to the session list (the split keeps its shape), an empty pane is what ✕ actually removes
Views	Bar → Views: a split with 2+ sessions is remembered automatically; click to restore, ✕ to delete
Check for updates	Refresh icon at the right of the bar: checked every 24h, red dot on a new release, confirm to update

Shortcuts (module defaults; rebind in Settings → Shortcuts):

Command	Default (desktop)
Focus previous / next pane	Mod+Alt+[ / Mod+Alt+]
Maximize or restore the focused pane	Mod+Alt+M
Remove the focused pane from the split	Mod+Alt+W

The browser (Web) shell gets no default bindings: DSH's shortcut layer accepts a very narrow set of web/Linux combinations, and forcing one fails at boot with "reserved". Desktop defaults work; bind them manually on Web.

Not supported in v1 (on purpose)

1. File preview / diff inside a pane — whenever any global panel is active, DSH unmounts the right sidebar's session surface (no session surface is mounted; shipped panels behave the same). Use ↗ to work in the native view.
2. Creating a session inside a pane — the hero's workspace picker is application-level navigation. Create sessions natively.
3. Trajectory / plugin view switching per pane — panes are pinned to Chat; no invented tabs.
4. Sidebar click routed into the focused pane — that needs interception of a private navigation path; sidebar clicks keep their native behaviour (they leave the split).
5. Auto-sleep — resources are released when a pane is removed or rebound; there is no pretend "pause rendering of unfocused panes".
6. More than four panes.

Performance

Measured with a CDP rAF sampler on desktop-kfscv8c-1 (1530×851 window):

Scenario	p50	p95	max	long tasks >50ms	JS heap
Native conversation (baseline)	16.7ms	16.7ms	16.8ms	0	43MB
Four panes mounted, idle	16.7ms	16.8ms	16.8ms	0	75MB
Four panes, two streams at once	16.7ms	16.7ms	16.8ms	0	85MB
Four panes, four long streams at once	16.7ms	50ms	150ms	2	53MB

Four long streams is the heaviest case measured: still near 60fps on average, but p95 rises to 50ms with an occasional 150ms frame (four virtualized transcripts re-laying out per chunk). v1 deliberately does not throttle — "every pane stays a real Chat" wins over a frame number.

Transcripts are virtualized per turn by DSH itself, so a pane costs roughly one active turn plus one editor instance. Below 900px wide or 520px tall the stage degrades to a single pane plus a pane switcher; the layout tree is preserved.

Development

No third-party dependencies; Node ≥ 22.18 (this repo uses 24.13).

npm run build     # src/client/*.ts → client.js (single-file bundle); src/host/index.ts → index.js
npm test          # layout algebra unit tests (node --test)
npm run check     # release self-check: manifest / artifacts / copy / size

Isolated verification (writes no profile):

dsh --profile web --patch <repo>\.dev\dev.patch.yml --port 40602 --no-open

The overlay's row name is an absolute file:/// URL to this repo's index.js (the Loader anchors relative row names at the profile root, not beside the patch file).

The client only uses public slot surfaces: a keyed main panel, a private child slot, SessionProvider, the conversation.content factory (variant:'embedded'), sessions.retain, shortcuts and locale. See docs/DESIGN.md.

License

MIT.