dsh-plugin-mobile-shell

Narrow-viewport affordances for the DeepSeek Harness web UI: a drawer sidebar with a hamburger and scrim, swipe gestures, and a deployment-labelled browser tab title.

It replaces a set of hand-applied patches to @deepseek-ai/dsh-client-ui-layout's compiled bundle — the kind that has to be re-applied after every npm i -g and that breaks silently when the upstream build changes a hashed class name.

Install

Not on npm yet. The built lib/ is committed, so it installs straight from GitHub — no download, no build step:

dsh plugin --profile web add github:ghbhiee/dsh-plugin-mobile-shell

Or from a local clone (a link:, so a local rebuild is picked up):

git clone https://github.com/ghbhiee/dsh-plugin-mobile-shell.git
dsh plugin --profile web add ./dsh-plugin-mobile-shell

Sibling plugins install the same way: dsh-plugin-workbench, dsh-plugin-mobile-shell, dsh-plugin-cli-session.

Develop

pnpm install
pnpm run check   # typecheck → vitest → tsdown build

Because lib/ is versioned (it is what a git install serves), rebuild and commit it with every source change.

Configure

- id: mobile-shell
  config:
    narrowMaxWidth: 1440        # frame width at or below which the drawer takes over
    documentTitle: 'WB · {host}' # '' leaves the shell's own session title alone

A client entry never sees its row's config, so the browser half asks for these over a small host route and falls back to the defaults (1023 / DSH · {host}) if it cannot.

What it does

Below the configured frame width (1023px by default — the threshold the shell itself uses to auto-collapse the sidebar):

• Drawer sidebar. The grid collapses to one column and the sidebar floats over the conversation instead of squeezing it, with a hamburger at the top left and a scrim behind it.
• Direction-aware swipe. Swipe right to open, left to close. (The patch this replaces toggled on either direction, so a left swipe on a closed drawer opened it.)
• Tapping a group keeps the drawer open. An expandable row carries aria-expanded; a leaf does not, and picking a leaf closes the drawer as you would expect after navigating.

At any width:

• The tab title reads DSH · <hostname>, so several deployments are distinguishable in a row of tabs. It is pinned with a MutationObserver on <title>, so it survives the shell's own session-title projection.

How it hooks in

Everything is plugin-space:

• The controls are one shell.overlay registration — the frame-wide layer that exists for exactly this.
• Behaviour drives ctx.layout.toggleSidebar(), the cross-plugin panel face.
• The drawer geometry is a global stylesheet keyed on stable DOM contract only: the [data-shell-overlay] layer (used to identify the frame via :has()) and the frame's data-sidebar-collapsed attribute. No compiled CSS-Module hash class is referenced anywhere, and colors come from --dsw-alias-* tokens.

Two things worth knowing if you extend this:

• data-sidebar-collapsed is absent when open, not "false" — React drops a false-valued data-* prop. Match :not([data-sidebar-collapsed='true']).
• One threshold, not two. The drawer's CSS keys on a data-mobile-shell-narrow mark the component sets from its measurement, not on a @media query — a media query would be a second copy of the threshold that silently diverges the moment it is configured.
• Narrow-ness is measured from the frame box with a ResizeObserver, not from matchMedia. That mirrors how the shell decides, and a media-query listener can miss viewport changes that never fire change (devtools emulation, pane resizes), which strands the hamburger on a wide layout.

Tests

pnpm test covers the two contracts that broke during development — the absent-when-open attribute and frame-measured narrowness — plus the drawer controls, leaf-vs-group closing, and swipe direction. Reverting either historical bug turns 7 of the 17 red, so the net demonstrably holds.

Known limitations

• The "reclaim vertical padding" tweak was dropped. The patch it came from targeted compiled CSS-Module class names (.wSkVaW_header), of which the current build has five variants — it would fail silently on the next upstream release. The center column instead gets top padding so the hamburger does not cover content.
• Swipe listens on the whole document, so a horizontal drag inside a scrollable area can still move the drawer.