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Mend

VS Code extension

The Mend extension for VS Code (apps/vscode) lists your projects and sessions and opens a session inside its workspace over SSH. The editor’s files are the session’s worktree, and its integrated terminal runs in the workspace, with the workspace image, environment and harness home. A claude or codex you run in that terminal is observed by Mend: the session shows running, the workspace stays up, and the conversation is recorded and can be resumed from any device.

The extension is not published on the Visual Studio Marketplace. Build and install it from source as described below.

Requirements

Section titled “Requirements”
  • VS Code 1.100 or newer.
  • Microsoft’s Remote - SSH extension (ms-vscode-remote.remote-ssh). Without it, opening a session offers Install Remote SSH or Copy code command, which copies the code --remote … command that opens the same folder.
  • A Mend server with a workspace SSH gateway. When the server reports none, the extension says This Mend deployment exposes no workspace SSH gateway. and opens nothing.

The extension never falls back to opening the worktree’s path on the Mend host. A terminal there would run outside the workspace, where Mend does not observe it. Mend: Copy worktree path copies that server-side path for your own use.

The Mend view

Section titled “The Mend view”

The Mend icon in the Activity Bar opens Projects and sessions. It groups sessions waiting for you under Needs you, then lists projects with their sessions and each session’s status. Clicking a session opens it. The status bar shows the project the open folder belongs to and how many sessions are waiting. When the open folder belongs to an adopted project, the view shows that project only; Mend: Toggle current project scope switches between it and every project.

With no project adopted, the view offers Adopt a project…, which asks for a Git clone URL and a project name.

Start a session

Section titled “Start a session”

Click + in the view, or run Mend: New Session…, and pick one of:

  • Workbench: a fresh worktree whose workspace is held open by a shell. VS Code opens in it, and you run claude or codex yourself in the terminal. Mend observes and records it.
  • Claude agent or Codex agent: Mend starts the harness on a prompt you type, and the workspace opens in VS Code beside it. An empty prompt starts the harness without one.
  • Agent with options…: choose the harness, model, thinking level, permissions (skip permission prompts, or ask before acting) and base branch.

Mend: New session in this worktree… on a session starts a second session in the same worktree: the same files and branch, with a new conversation. Each session keeps its own harness state, so the new session does not see the first session’s conversation. To continue that conversation, take the session over instead.

Mend: New worktree without an agent… asks for a name and a base, creates the worktree, and opens it.

Open a session

Section titled “Open a session”

Opening a live session opens its workspace. Opening a settled session asks whether to resume it as a workbench shell. The shell starts a fresh workspace over the same worktree and keeps it up while the editor is attached. No agent is launched.

Workspace SSH setup

Section titled “Workspace SSH setup”

The first open asks Set up workspace SSH?. Setup registers this machine’s SSH public key with Mend and adds one server-specific Host block at the start of ~/.ssh/config, before any wildcard entries. It keeps hand-written configuration and blocks for other Mend servers. On later runs it reuses the key it chose. On first setup it can use a key from your SSH agent or create a dedicated key under ~/.config/mend/ssh. It never prompts for a passphrase: an encrypted or missing private key has to be loaded in an unlocked agent.

Setup writes configuration and registers the key. It does not test the connection or check the gateway’s host key. OpenSSH accepts an unknown host key on the first connection and refuses a changed one, and Mend never clears known_hosts.

Run Mend: Set up workspace SSH, or mend ssh setup in a terminal, to redo it. The SSH hostname comes from the Mend server URL, and the server supplies the port. Set mend.workspaceSshHost to use another hostname.

Take over a running session

Section titled “Take over a running session”

Opening a session whose agent Mend is running elsewhere, such as a mend codex in a terminal or a session picked up on the phone, asks whether to Open alongside it or Take over in the editor. Mend: Take over session in the editor on a live session goes straight to the takeover.

The editor cannot attach to Mend’s terminal for the agent, so a takeover works like this:

  1. A confirmation names the agent that will end and the command that will resume it.
  2. Mend opens a shell in the session, which keeps the workspace up, and stops the running agent.
  3. The workspace opens in VS Code, or the current window is used when it is already that workspace.
  4. A new integrated terminal runs the harness’s own resume: codex resume <id> or claude --resume <id>. Without a known id it runs codex resume --last or claude --continue.

The harness home lives in the workspace, so the resume finds the conversation the agent was writing, and Mend observes the new process as the same conversation. Cancelling the SSH setup or the confirmation leaves the agent running. The stop ends only the agent; the shell keeps the workspace open until you stop the session.

Only claude and codex sessions can be taken over here. The extension says so and gives the mend attach command to use from a terminal instead.

Other commands

Section titled “Other commands”
Command What it does
Mend: Open in VS Code Open the session’s workspace
Mend: Open in Mend Open the session or project in the web app
Mend: Stop session Stop a live session; the worktree and its change remain
Mend: Show project sessions Pick a session of the current project, or start something new
Mend: Refresh Reload the view

A link of the form vscode://sealant-sh.mend/open?session=<session-id> opens that session in VS Code, with the same takeover question for a running agent.

Sign-in

Section titled “Sign-in”

The extension reads the connection the CLI saved, $XDG_CONFIG_HOME/mend/cli.json (~/.config/mend/cli.json by default): its server URL and token. If you ran mend login on this machine, there is nothing to set up. With no URL configured anywhere, it uses http://localhost:3105.

Mend: Connect to server overrides the CLI’s connection. It asks for a server URL, which it saves as the mend.serverUrl setting, and an access token, which it keeps in VS Code’s secret storage. An empty token removes the stored one, for a local server that does not require a token. The CLI’s token is used only while mend.serverUrl points at the same URL as the CLI’s configuration.

Install from source

Section titled “Install from source”

You need a checkout of the repository with its toolchain: Node (the repository pins 26.4.0 in .node-version) and pnpm.

Terminal window
git clone https://github.com/sealant-sh/Mend.git
cd Mend
pnpm install
cd apps/vscode
pnpm build
pnpm package
code --install-extension mend-0.1.0.vsix

pnpm build bundles the extension into dist/, and pnpm package writes the .vsix named after the version in apps/vscode/package.json. Reload VS Code after installing.