dsh-restart-button

One-click restart for the DeepSeek Harness desktop app — a small refresh button in the sidebar brand row, next to DeepSeek Harness, plus an HTTP route so an agent (or a script) can restart the app itself.

中文说明

The restart button, immediately right of the wordmark.

⚠️ One profile patch is required before the button appears

The sidebar's brand row is a single slot, and dsh-client-ui-slots throws on a second registration for a single slot — so the shipped @deepseek-ai/dsh-client-ui-brand-official occupant has to step aside first.

Without it the plugin installs and its HTTP routes work, but the button never shows.

Append install/profile-patch.yml to $DSH_HOME/profiles/<profile>/cordis.patch.yml — see Install.

---

The problem

The packaged DeepSeek Harness desktop build has no way to restart itself:

Where you would expect it	Reality
Tray context menu	Only Open and Quit
Application menu	Restart App and Host exists in the code, but it sits behind const development = !app.isPackaged — development builds only
Closing the window	Hides to the tray instead of quitting

So every plugin install or configuration change that needs a fresh process means quit from the tray → find the icon → launch again. This plugin adds the missing button.

Requirements

OS	Windows (the restart worker uses WMI, wscript.exe and Win32 foreground activation)
Host	DeepSeek Harness 0.2.0-rc.2 desktop build
Profile patch	Required — one disabled: true row, see step 1 below. Without it the plugin installs but the button never appears.

Install

1. Add the profile patch (required — do this first)

The sidebar's 7 render targets are almost all single slots, and the slot registry throws on a second registration for a single slot (dsh-client-ui-slots: single slot "<name>" already has a registration). The brand row is owned by the shipped @deepseek-ai/dsh-client-ui-brand-official, so that occupant has to step aside. The sidebar itself documents that as supported — "a deployment can replace the brand mark or name" — and this plugin re-renders the official wordmark, so the title looks unchanged.

Append to $DSH_HOME/profiles/<profile>/cordis.patch.yml:

- id: ui-brand-official
  name: "@deepseek-ai/dsh-client-ui-brand-official"
  disabled: true

The same lines, with the full rationale and the revert instructions, are available as a copy-paste fragment: install/profile-patch.yml.

(ui-brand-official is the row id declared in @deepseek-ai/dsh-web-app/cordis.patch.yml.)

2. Add the bundle

A DSH plugin is an ordinary profile bundle, so either of these works:

# from this repository
dsh plugin --profile desktop add git+https://github.com/FIZMIE/dsh-restart-button.git

# from a local checkout
dsh plugin --profile desktop add C:\path\to\dsh-restart-button

3. Refresh the page

Client changes are picked up by dsh-client-modules without a process restart, so a browser refresh is enough. The button appears immediately right of the DeepSeek Harness wordmark.

What you get

• Brand-row button — a refresh glyph next to the wordmark. Click it, confirm, and the whole application restarts: the window disappears, comes back by itself, is brought to the foreground, and the page reloads.
• Agent / script route — POST /dsh-restart-button/restart, so an agent can restart the app without asking you to click anything.

HTTP API

Everything is mounted on the host web server under /dsh-restart-button:

Method	Path	Purpose
GET	/status	Process identity, resolved executables, whether a restart is possible
GET	/health	bootId + uptime; the browser half polls it to notice the new process
POST	/restart	Schedules a restart and answers 202 before the app goes away

POST /restart is accepted only from a loopback peer, and only when the request carries either the app's own origin or the local token written to $DSH_HOME/.dsh-restart-button/token. That token is the agent-facing path:

$token = (Get-Content "$env:DSH_HOME\.dsh-restart-button\token" -Raw).Trim()
Invoke-RestMethod -Method Post -Uri "http://127.0.0.1:19387/dsh-restart-button/restart" `
  -Headers @{ 'X-DSH-Restart-Token' = $token }

How it works

Restarting this particular application turns out to be surprisingly awkward, and the code carries the reasons inline. The short version:

The process model

The Desktop shell (lib/main.js) is the Electron main process. It spawns the DSH host — and therefore every plugin — as a child process with ELECTRON_RUN_AS_NODE=1 and an IPC channel. A plugin can therefore not call app.relaunch(), and the child→parent IPC protocol only carries a ready event, so there is no "please restart" message to send either. The restart has to be performed by a separate process.

The out-of-tree worker

The first attempts spawned a helper that killed the app and then relaunched it. It worked — right up until the app died: the helper died with it, and restart.log simply stopped after the kill line. The reason is that the helper was still a descendant of the application, and the application's process tree (job object) is torn down with it.

The fix is to not be in that tree at all. The helper's first action is to create a copy of itself through the WMI provider:

Invoke-CimMethod -ClassName Win32_Process -MethodName Create -Arguments @{ CommandLine = '...' }

A process created that way is parented to WmiPrvSE.exe — a service process — and runs in the interactive session (so a GUI application started from it is still visible). That worker then waits for the old app to disappear, relaunches it, and foregrounds its window. A wscript.exe + .vbs launcher starts the worker windowless, and waits for it (Run cmd, 0, True) because — also measured — a non-detached child does not survive a parent that exits immediately.

Four Windows traps worth knowing

Trap	Consequence	What this plugin does
The host child runs with ELECTRON_RUN_AS_NODE=1	Passed to DeepSeek Harness.exe, it boots as a bare Node process: a console window appears, the GUI never does, and the restart looks like it killed the app	Strip the variable for the child environment
windowsHide means STARTF_USESHOWWINDOW + wShowWindow = SW_HIDE	A GUI application's first ShowWindow obeys it, so the window exists but stays hidden until you click its taskbar button	Never pass windowsHide for the application spawn
detached: true and a detached powershell.exe	A detached console program that needs a console never runs at all	The helper (a Node process) may detach; the PowerShell activation step must not
"Is the process there?" is not "is the window up?"	The old helper reported success while the user was still staring at nothing	Confirm against the web port answering again, and log the real elapsed time

It also kills by PID rather than shelling out to taskkill (one fewer console process, and ~1.1 s less on the critical path), caps relaunch attempts at 5, and logs everything to $DSH_HOME/.dsh-restart-button/restart.log.

What a restart actually looks like

One real restart on Windows, copied from $DSH_HOME/.dsh-restart-button/restart.log:

15:00:53.877 [primary] wmi create -> ReturnValue=0 pid=24172
15:00:53.877 [primary] relaunch delegated to out-of-tree worker pid 24172
15:00:53.919 [worker]  helper start pid=22748 port=19387 main=10192 host=20620
15:00:55.079 [primary] kill main(10192)=true host(20620)=true
15:00:55.141 [worker]  port 19387 free after 800ms
15:00:55.159 [worker]  relaunch attempt 1/5: spawned pid=23248
15:00:57.679 [worker]  app is listening on 19387 after 2535ms (attempt 1)
15:00:57.690 [worker]  activation requested for pid 23248
15:00:59.436 [activate] brought the window to the foreground

The whole design is visible in that ordering: the primary creates the out-of-tree worker before killing anything, the worker is already running on the next line, and its port free line comes after the application was terminated — which is precisely what used to fail. From terminating the old process to the window being back in the foreground takes about 5.5 seconds, of which 2.5 seconds is DeepSeek Harness's own startup.

Requirements and limitations

• Windows only. The out-of-tree worker uses WMI, wscript.exe and Win32 foreground activation.
• Built against DeepSeek Harness 0.2.0-rc.2. It reads the launcher's profileContext service and mutates nothing but its own files, but it does depend on internals that can move.
• The restart is a hard kill (TerminateProcess), not a graceful shutdown: in-flight work is interrupted. DSH session data is append-only JSONL, so the risk to stored data is low, but it is not zero.
• The kill is by PID (the Electron main plus the DSH host child), so other processes are untouched.
• Relaunching is bounded: at most 5 attempts, then it gives up and says so in the log.
• Much of the remaining wait is DeepSeek Harness's own startup time, not this plugin's — the log records app is listening on <port> after <n>ms so you can tell them apart.

Tools

Two small utilities, also used while developing this:

# Regenerate the runtime artefacts from the templates inside lib/index.js and assert
# every invariant this plugin depends on (10 checks).
node tools/extract-helper.mjs

# Restart the running app from outside the plugin — the bootstrap path for when
# lib/index.js itself changed, since host-side JavaScript only takes effect in a
# new process.
node tools/launch-helper.mjs

npm run check runs the first one against a throwaway directory.

License

MIT — see LICENSE.