---

description: "Per-session persistent PTY bash terminals for DeepSeek Harness, with asynchronous command jobs." kind: "plugin-bundle"

dsh-shared-bash

Session-keyed, persistent PTY bash terminals for DeepSeek Harness, with an asynchronous job model for commands.

Every DSH session gets one long-lived shell. The shell is addressed by that session's id, so you can attach to the terminal an earlier session left behind — with its working directory, variables, functions and running process intact — instead of starting from scratch. A command handed to it returns a job handle immediately; the result is collected later with a wait, or read while it is still running.

Requirements

• DeepSeek Harness ^0.2.1-rc.2
• A composed subprocess provider with PTY support. The desktop composition mounts @deepseek-ai/dsh-subprocess-local + dsh-experimental-terminal-bundle; on Windows the default shell is MSYS2 bash at C:\msys64\usr\bin\bash.exe.

Install

dsh plugin --profile desktop add git+https://github.com/snowy-yang/dsh-shared-bash.git

Quit the app before running that: pnpm rewrites the profile's node_modules and fails with ERR_PNPM_EPERM while the Host holds the files.

Tools

Tool	What it does
bash_attach	Attach to a session's terminal, opening one if that session has none. Optional cwd; recreate replaces an existing shell.
bash_exec	Run one command, return a job id immediately. Optional wait_ms returns the finished result when it is faster.
bash_wait	Wait for a job, returning exit code, output and timed_out.
bash_read	Read retained output of a terminal without sending input.
bash_interrupt	Send SIGINT to the foreground process group — a real Ctrl-C; the shell survives.
bash_close	Close one terminal or all of them.
bash_list	List terminals with session id, status, cwd and whether a command is running.

Every tool takes an optional session_id. Omitted, it means "the calling agent's own session"; passed, it means "that session's terminal", which is the explicit cross-agent sharing this plugin offers:

bash_list              → 3f2a… · busy · C:\proj\widgets
bash_read   {session_id: "3f2a…"}
bash_exec   {session_id: "3f2a…", command: "git status --short"}
bash_wait   {job_id: "bash-9c1e…"}

Terminal model

• One PTY per DSH session id; the registry is profile-wide, the shell is not shared behind your back.
• bash -l -i: an interactive login shell, so MSYS2's PATH and the user's profile apply. A requested cwd is cd-ed inside the shell, and POSIX paths such as /tmp are translated to the MSYS2 installation (C:\msys64\tmp).
• The shell keeps working directory, exported and shell variables, functions, aliases and any process you background between calls.
• Commands are written to a script file and sourced with stdin from /dev/null, so heredocs, loops, pipes and quoting behave exactly as in a script, and a command that tries to read stdin gets EOF instead of stealing the terminal's input.
• Completion is detected with a sentinel printed by the shell after the command, carrying a token that lives only in the environment — terminal echo of the command line cannot fake it.
• Output is retained in a 4000-line ring per terminal, with ANSI escape sequences stripped.

Asynchronous commands

bash_exec never blocks on the command: it returns {job_id, session_id, status}. Three ways to continue:

bash_exec  {command: "npm run build"}        → job bash-9c1e…, status running
bash_wait  {job_id: "bash-9c1e…"}            → blocks until done, returns exit_code + output
bash_read  {}                                → what the terminal has printed so far
bash_interrupt {}                            → SIGINT, job settles as interrupted

Only one command runs per terminal at a time; a second bash_exec on a busy terminal is refused with SESSION_BUSY. bash_wait with a short timeout_ms returns timed_out: true and leaves the command running, so it can be polled.

Settings page

Settings → Bash terminals lists every terminal by session id, shows retained output, sends commands (as jobs), interrupts them, attaches a new session id and closes terminals.

It is served by the plugin's own JSON API under /api/shared-bash: GET /sessions, GET /output?session_id=…, GET /wait?job_id=…, POST /attach|/exec|/interrupt|/close. The harness web server has no request policy of its own, so this route fences itself: the composition's connection service when present, otherwise loopback-only Host plus matching Origin/Referer (with the dsh-app://app relay allowed only on its own).

Configuration

cordis.patch.yml defaults, all optional:

Key	Default	Meaning
bashPath	C:\msys64\usr\bin\bash.exe	Shell executable
msystem	MSYS	MSYSTEM value for the shell
login	true	bash -l -i instead of --noprofile --norc -i
cwd	Host process cwd	Startup directory when a terminal gets none
maxLines	4000	Retained output lines per terminal
maxSessions	16	Concurrent terminals per profile
cols / rows	120 / 30	Reported PTY geometry

Limits

• One command per terminal at a time; parallel work needs parallel sessions.
• The web page is a settings surface, not a full emulator: it shows stripped text output, not a live screen.
• Terminals are process-local: they end with the Host, and they are not a sandbox — a shell runs with the Host's own permissions.

Development

node --test test/

Tests substitute a piped bash -s for the PTY through the same spawnTerminal contract the harness provides, so framing, jobs, the registry and the HTTP API are exercised without the app. DSH_TOOLS_MODULE additionally validates the tool schemas against the harness's own assertSupportedJsonSchema.

MIT licensed.