>_ dtach Sessions

A minimal VS Code extension that lists dtach sessions in a sidebar and attaches to them in ordinary integrated terminals. Because dtach is pure passthrough, native terminal select, copy, scroll, and search all keep working. There's no webview or PTY proxy.

Built for the Remote-SSH workflow: the extension runs on the remote extension host (extensionKind: ["workspace"]), where the dtach sockets and binary live.

Requirements

• dtach on the remote host. If it is not on the extension host PATH (the extension host does not source your .bashrc), set dtachSessions.dtachPath to an absolute path such as /home/you/.local/bin/dtach.
• For the Kill command: lsof (preferred) or pgrep on the host. Kill uses lsof -t <socket> to find the owning process and falls back to a regex-escaped pgrep -f if lsof is unavailable; it then removes the socket.

Features

• Session list — sidebar showing sockets in <socketDir> that end in .dtach and are actually sockets (default ~/.dtach-sessions). Sessions are ordered most recently modified first, each row showing a relative age (e.g. 2h ago); a row whose terminal is open in the current window is marked attached with a green icon. Refreshes manually via the title-bar button, automatically when the view becomes visible, and shortly after a session is created.
• Attach — click a row to open a terminal running dtach -a <socket> -r winch. The -r winch forces a redraw so a live TUI renders immediately. Clicking a session that already has an open terminal focuses it instead of opening a second. By default (dtachSessions.reflectProcessTitle) the terminal is created without a fixed name so the running program's title drives the tab (e.g. an agent CLI's live status), while the session name labels the sidebar row. Until the program sets its own title, the tab falls back to the session name (dtach is launched with that as its process label via argv[0]). Set the option to false to pin the session name on the tab instead. See the title note below for limits.
• Create — the + button prompts for a name (validated against empty, whitespace, and slashes) and opens dtach -A <socket> -r winch $SHELL. Sockets are named <prefix><name>_<hash>.dtach; the _<hash> is a stable id that lets a session be renamed without losing track of its process. Set dtachSessions.startupCommand to auto-run a program (e.g. claude) in new sessions.
• Open in Detach Session — right-click a folder in the Explorer. The session is named after the folder: if one already exists it is attached (reusing its open terminal if any), otherwise a new session is created with the shell rooted in that folder.
• Switch Session — a command-palette command (dtach Sessions: Switch Session) to fuzzy-find and attach a session without leaving the keyboard.
• Rename — right-click a row → Rename. Moves the socket (keeping its id) and relabels the open terminal. The live session survives.
• Detach / Attach — each row carries an inline icon for its primary action: attached rows show a blue pause (detach — close this window's terminal, leave the dtach server running); detached rows show a play (attach). The same actions are on the right-click menu.
• Restart — the inline restart icon (or right-click → Restart, with confirmation) terminates the dtach server and opens a fresh shell under the same name, re-running startupCommand. Use it to relaunch a session that's wedged; in-session scrollback does not survive.
• Copy — right-click a row → Copy Socket Path / Copy Attach Command for scripting or SSH.
• Kill — the inline trash icon (or right-click → Kill), with confirmation, terminates the dtach server and removes its socket. Select multiple rows to kill them together, or use Kill All Sessions from the view's … menu. The owning process is resolved by the session id, so renamed sessions are killed cleanly rather than orphaned.

Configuration

| Setting | Default | Description | | --- | --- | --- | | dtachSessions.socketDir | ~/.dtach-sessions | Directory holding the sockets (~ expands to home). Created on first session. | | dtachSessions.socketPrefix | (empty) | Filename prefix; files are `<prefix><name>_<hash>.dtach`. See the migration note below. | | `dtachSessions.startupCommand` | (empty) | Command run inside a session's shell on create (not reattach), e.g. claude. | | dtachSessions.redrawMethod | winch | -r value on attach/create. One of winch, ctrl_l, none. See note below. | | dtachSessions.dtachPath | dtach | Path to the dtach binary; set absolute if not on PATH. | | dtachSessions.reflectProcessTitle | true | Create attach terminals without a fixed name so the running program's title (e.g. an agent CLI's live status) drives the tab. The session name still labels the sidebar row. Set false to pin the session name on the tab. |

Migration note (prefix default): the default socketPrefix is now empty (was .claude-). Sockets created by older versions are named .claude-*.dtach and will not appear under the new default. To keep seeing them, set dtachSessions.socketPrefix back to .claude-, or kill and recreate those sessions under the new naming.

Redraw note: winch repaints on reattach only when the terminal size differs from the size at detach — reattaching at the same size can leave a TUI blank until the next resize. ctrl_l forces a redraw regardless of size, but it sends a literal Ctrl-L to the program, which some TUIs (including Claude) treat as a clear-screen keystroke. Pick whichever trade-off suits your workflow.

Title note (reflectProcessTitle): VS Code only honours an escape-set tab title from a process it detects as an agent CLI (Claude Code, Copilot, Gemini), so the extension can't seed the tab itself — when you resume an idle agent it won't re-emit its title until it next changes state, so the tab shows the session-name fallback until then. Separately, agent CLIs running under dtach may log a VS Code IPC/extension-install error and lose editor integration on reattach: dtach freezes the program's environment at creation, so the VSCODE_IPC_HOOK_CLI socket it inherited goes stale when you reattach from a different window. Both are inherent to a detached-session model and harmless to the program itself; set reflectProcessTitle: false if you'd rather just pin the session name on the tab.

Build

npm install
npm run compile          # tsc -p ./  ->  out/
npx @vscode/vsce package # -> dtach-sessions-<version>.vsix

Install onto the remote host

In a Remote-SSH window: Command Palette → Extensions: Install from VSIX… → select the .vsix. VS Code uploads and installs it remote-side. Reload the remote window.

Acceptance checks

1. + → web creates ~/.dtach-sessions/web_<hash>.dtach, opens a shell, and a web row appears (showing a relative age).
2. Clicking the row opens a terminal; a live TUI renders immediately, and the row shows as attached (green icon).
3. With startupCommand set to claude, a freshly created session auto-runs it.
4. Right-click web → Rename → api: the socket becomes api_<hash>.dtach, the row and terminal relabel, and the session stays live.
5. Right-click api → Kill → process gone (verify with pgrep -f _<hash>.dtach) and socket removed; renaming did not orphan it.
6. Reopen the remote window, click a session → it is still there and reattaches.
7. Select several rows → Kill, or use Kill All from the … menu → all gone.
8. Drag-select and right-click-copy work natively in the attached terminal.