dsh-silent-pwsh

A DeepSeek-Harness plugin for Windows that makes sandboxed (confined) pwsh / bash calls spawn their console window hidden (SW_HIDE) — no black console window flashes on every command.

Problem

Every sandboxed pwsh call in DeepSeek-Harness runs through the windows-acl runner (dsh-sandbox-windows-acl/lib/runner.js), which spawns the confined child with a fresh console window unless STARTF_USESHOWWINDOW | SW_HIDE is set in the child's STARTUPINFOW. The shipped package omits it, so every confined command flashes a black console window on the desktop. (CREATE_NO_WINDOW is not an option: under the restricted token it makes the child die with STATUS_DLL_INIT_FAILED (0xC0000142) — verified by the DSH maintainers. SW_HIDE keeps the console alive and simply never shows it.)

Two related flashes are also fixed: the process-tree taskkill termination and the one-time sandbox capability probe, whose spawns lacked windowsHide.

How it works

DSH's plugin model is loader-config patches plus Cordis plugins; no config seam can change those native spawn flags. So this plugin is a self-healing patch plugin: on every host start (before any confined command runs) it idempotently checks and re-applies a three-file patch:

File (under <host>\node_modules)	Patch
@deepseek-ai/dsh-sandbox-windows-acl/lib/types-CNjZgO4h.js	both encodeStartupInfo calls: dwFlags: 256 → 257 (+STARTF_USESHOWWINDOW), add wShowWindow: 0 (SW_HIDE)
@deepseek-ai/dsh-subprocess-local/lib/index.js	taskkill spawnSync gets windowsHide: true
@deepseek-ai/dsh-sandbox-local/lib/index.js	windows-acl capability probe spawnSync gets windowsHide: true

The patch only rewrites files that are in the expected pre-patch shape; if an upgrade changes them, it warns and skips instead of corrupting them. Reinstall or upgrade the app and the patch is re-applied automatically on the next boot.

Install

Requirements: DeepSeek-Harness desktop app, node and pnpm on PATH.

From GitHub (recommended)

dsh plugin --profile web add github:chengyimingvb/dsh-silent-pwsh
# or with a full URL
dsh plugin --profile web add https://github.com/chengyimingvb/dsh-silent-pwsh

From a local folder / zip

# extract the zip, cd into dsh-silent-pwsh, then:
.\install.ps1                      # installs into the 'web' profile
.\install.ps1 -Profile headless    # or another profile
# if blocked by execution policy:  powershell -ExecutionPolicy Bypass -File .\install.ps1

Then restart DeepSeek Harness. The host log will show [silent-pwsh] up to date (or [silent-pwsh] patched … when it had to heal).

Gotcha: if pnpm fails with a supply-chain policy error (minimumReleaseAge), add the reported package@version to the profile's pnpm-workspace.yaml minimumReleaseAgeExclude list and re-run.

Uninstall

dsh plugin --profile web remove dsh-silent-pwsh

The patched files are left as-is. To restore the shipped files manually:

$chunk = "$env:ProgramFiles\DeepSeek Harness\resources\host\node_modules\@deepseek-ai\dsh-sandbox-windows-acl\lib\types-CNjZgO4h.js"
(Get-Content $chunk -Raw) -replace 'dwFlags: 257,`n`t`twShowWindow: 0,', 'dwFlags: 256,' | Set-Content $chunk -NoNewline -Encoding utf8
# likewise remove ', windowsHide: true' from the taskkill and probe spawnSync calls.

Configuration

• DSH_INSTALL_ROOT — point at the directory containing node_modules when the host root cannot be auto-detected. Default detection: <app dir>\resources\host derived from process.execPath, with cwd and plugin-location fallbacks.

Development / verification

node test.mjs   # idempotence against the real host files + heal-a-reverted-copy round trip

Verified: confined pwsh still executes correctly through the runner (exit 0, output flows through inherited stdio, no 0xC0000142 regression).

Notes for maintainers

The packaged app already ships a fixed-but-unused chunk (types-C1ecepac.js); wiring the entry imports to it is the upstream fix. This plugin exists so users on shipped builds get the behavior now, self-healing across reinstalls.

License

MIT