dsh-gitbash-preset

DeepSeek Harness plugin: one-click install of the "Minimal Mode (Git Bash)" agent preset — maps the bash invocations in DSH's built-in minimal mode to Git for Windows's bash (MSYS), making minimal mode actually usable on Windows.

About

DSH's built-in minimal mode does not work on Windows, for two reasons:

1. PTY platform limitation: minimal mode's persistent bash depends on the PTY backend, and @deepseek-ai/dsh-subprocess-local rejects it outright on win32 (terminal inspection is unsupported on platform win32), regardless of whether bash is present;
2. Missing shell: even if you bypass the PTY, @deepseek-ai/dsh-bash-local hardcodes looking up bash from PATH, which is not present by default on Windows.

This plugin ships an installable preset variant: the same minimal persona + str_replace_editor dual-tool surface, but the bash tool executes <git bash> -c <command> for each command, with sandbox-aware gating to ensure security boundaries are not bypassed.

Features

• Idempotent installation: at startup, the plugin copies the bundled preset into the user preset root (${DSH_HOME:-~/.dsh}/.agent-presets/minimal-gitbash/); if it already exists it is skipped, and only force: true overwrites it;
• Automatic bash detection: GIT_BASH environment variable → common install directories (ProgramFiles / ProgramFiles(x86) / LOCALAPPDATA) → bash.exe on PATH → falls back to bash, no hardcoded paths required;
• Sandbox-aware gating: the MSYS runtime cannot start inside a Windows restricted-token sandbox (cannot create the signal pipe), so commands only run under the "full access" policy — no bypassing the sandbox, with clear upgrade guidance when restricted;
• Minimal stays unchanged: fixed persona, str_replace_editor, no context compression — identical to the original minimal mode.

How it works

Stage	Description
Plugin line	cordis.patch.yml inserts dsh-gitbash-preset into the web profile composition and installs the preset files at startup
Preset composition	In agent.cordis.yml, the gitbash-shell group provides the shell service with an entry-local realm, and tool-bash registers the model tool
Executor	gitbash-executor.mjs executes bash -c via the host's subprocess service, handling timeouts, background execution, output truncation, and error diagnostics
Sandbox gating	run/start validates the policy: only danger-full-access (or deployments without a sandbox) is allowed through; otherwise an error with guidance is thrown

Installation

dsh plugin --profile web add @icelily/dsh-gitbash-preset

Alternatively, manually merge cordis.patch.yml into the profile patch layer. Restart DSH to take effect; after restarting, the plugin will install the preset automatically (no-op if it already exists, and it will not overwrite your existing version).

You can also skip installing the plugin and simply copy the agent-presets/minimal-gitbash/ directory into ~/.dsh/.agent-presets/.

Usage

1. In the web UI, create a new session and select Minimal Mode (Git Bash);
2. Choose one of two ways to enable bash:
   • Switch the session sandbox to full access, and all bash calls will go directly through git bash;
   • Or keep workspace-write, and let the model upgrade once, after the first call fails, using sandbox_permissions: "danger-full-access" + justification as prompted (through the normal approval flow).

Config

Preset configuration (gitbash-executor in agent-presets/minimal-gitbash/agent.cordis.yml):

Field	Default	Description
shellPath	auto-detected	Explicit value takes priority when set (e.g., 'C:\\Program Files\\Git\\bin\\bash.exe')
timeoutMs	120000	Default timeout per command (capped by maxTimeoutMs)
maxTimeoutMs	600000	Maximum timeout
maxOutputBytes	64000	Bytes retained per stream (overflow is written to a spill file)
graceMs	3000	Grace period for SIGTERM→SIGKILL when terminating the process

Plugin configuration (the line inserted by cordis.patch.yml):

Field	Default	Description
force	false	Whether to overwrite with the bundled files when the preset already exists (user's extra files are preserved)

Development

npm run check   # 三个文件语法检查（插件、执行器、测试）
npm run test    # 单元测试：路径转换 / 探测优先级 / 配置校验，10 个用例

Limitations

• DSH version: the preset is written for the current @deepseek-ai/dsh-persona field name prefix. If your DSH is older (only accepts text), switching to the preset will report $.prefix missing required value — just change prefix: back to text: in agent.cordis.yml;
• Upgrade note: the installer is no-op by default for an existing preset, and presets installed by versions before 0.1.3 are broken (text field). After upgrading the plugin, set force: true in the plugin line configuration, or delete ~/.dsh/.agent-presets/minimal-gitbash/ and restart, to write the fixed files;
• When the session sandbox is workspace-write (or narrower), git bash cannot start (MSYS restricted-token limitation); you must switch to full access or do a one-time upgrade — this is a sandbox boundary and the plugin does not bypass it;
• Unlike the original minimal mode, bash is a fresh shell per invocation (cd/export state is not preserved) — persistent PTY sessions are unavailable on Windows, so this is a substitute design.

License

MIT