remote-ssh-mcp

An MCP server that lets coding agents work on a remote host through a persistent tmux+SSH session. Every tool call (run, read, write, edit, grep, glob) is routed through the same tmux pane on the remote, so you can tmux attach and watch the agent work in real time.

Why

Most coding-agent clients operate on the local filesystem and a fresh non-interactive shell per call. That makes "I want the agent to work on my remote server" awkward: you end up wrapping every command in ssh host '<cmd>', losing shell state (cwd, venv, env vars) between calls, and having no way to watch what's happening.

remote-ssh-mcp fixes that by:

• Opening one persistent tmux session per remote host, using ssh -A by default so forwarded-agent operations are available when your local agent is usable, and keeping shell state across calls.
• Giving each agent (parent + subagents) its own tmux window, so parallel work doesn't race on the same shell.
• Exposing a full toolkit (remote_run, remote_read, remote_write, remote_edit, remote_grep, remote_glob, …) that mirrors local agent tools — but every operation flows through the visible tmux pane.

You can tmux attach -t remote-ssh-mcp/<host> at any time to watch.

Status

Alpha. The current release ships with single-window-per-connection serialization and a 1MB cap on single-file reads. See Limitations.

Install

Prerequisites

• tmux 3.0+ on your laptop.
• An SSH config entry for the remote host (i.e. ssh <host> works in a normal terminal). Agent forwarding is requested by default via ssh -A; pass agent_forwarding=false to remote_connect to disable it.
• python3 on the remote host (used for atomic file writes via base64).
• uv on your laptop for the bundled auto-updating plugin config. If you install the MCP server manually, uv or pipx is fine.

As a plugin with bundled skills

The plugin bundles the MCP server and skills that brief MCP-capable agents on how to use it. In Claude Code, install it with:

/plugin marketplace add Square596/remote-ssh-mcp
/plugin install remote-ssh-mcp@Square596

The same plugin directory includes Codex metadata (plugins/remote-ssh-mcp/.codex-plugin/plugin.json) and a repo-local Codex marketplace entry (.agents/plugins/marketplace.json). Both Claude Code and Codex use the bundled .mcp.json plus the remote-ssh skill.

The bundled MCP config requires uv in PATH. On client startup it installs or upgrades the uv-managed tool from GitHub, then launches remote-ssh-mcp. That keeps Codex, Claude, Cursor, and other MCP clients on the latest GitHub version when they start a new session. Startup depends on GitHub/network availability.

Repository plugin layout

This repository carries both Claude Code and Codex plugin metadata:

• .claude-plugin/marketplace.json is the Claude Code marketplace catalog. Claude users add this repository as a marketplace and install remote-ssh-mcp from it.
• .agents/plugins/marketplace.json is the Codex marketplace catalog for the same plugin.
• plugins/remote-ssh-mcp/.claude-plugin/plugin.json is the Claude Code manifest for the plugin itself.
• plugins/remote-ssh-mcp/.codex-plugin/plugin.json is the Codex manifest for the plugin itself, including Codex UI metadata.
• plugins/remote-ssh-mcp/.mcp.json and plugins/remote-ssh-mcp/skills/remote-ssh/SKILL.md are shared by both plugin loaders.

For Claude Code, keep only plugin.json inside .claude-plugin/; component directories such as skills/ and config files such as .mcp.json live at the plugin root.

As an MCP server (any MCP client)

This section is for manual MCP setup when you are not installing the plugin package from a marketplace. The first JSON block intentionally mirrors plugins/remote-ssh-mcp/.mcp.json: plugin loaders read that file automatically, while plain MCP clients need an equivalent server definition in their own MCP config.

If you want auto-updates on each client startup and have uv in PATH, use the auto-updating stdio server directly:

{
  "mcpServers": {
    "remote-ssh": {
      "command": "sh",
      "args": [
        "-lc",
        "command -v uv >/dev/null 2>&1 || { echo 'remote-ssh-mcp plugin requires uv in PATH for auto-install. Install uv, or preinstall remote-ssh-mcp and configure your MCP client to run command: remote-ssh-mcp.' >&2; exit 127; }; uv tool install --quiet --upgrade git+https://github.com/Square596/remote-ssh-mcp >&2; exec \"$(uv tool dir --bin)/remote-ssh-mcp\""
      ],
      "env_vars": ["SSH_AUTH_SOCK"]
    }
  }
}

For Codex, env_vars forwards the local SSH_AUTH_SOCK value into the MCP server process so ssh -A can use your local ssh-agent. This requires Codex itself to be launched from an environment where SSH_AUTH_SOCK is set.

You can also install the Python package directly as a stable uv-managed tool:

uv tool install git+https://github.com/Square596/remote-ssh-mcp

Then add the installed command to your MCP client config:

{
  "mcpServers": {
    "remote-ssh": {
      "command": "remote-ssh-mcp"
    }
  }
}

For Claude Code CLI:

claude mcp add remote-ssh remote-ssh-mcp

Installed tools are stable until upgraded. To update the installed command:

uv tool upgrade remote-ssh-mcp

Usage

Once installed, ask your agent to connect to a host with the remote-ssh skill or call the tool directly:

remote_connect(host="<host>", project_path="/home/me/myproject")

<host> is whatever alias you use in ~/.ssh/config — the same string that works for plain ssh <host>.

The skill will:

1. Run local ssh-add, then connect via ssh -A <host>, opening a fresh tmux window in the remote-ssh-mcp/<host> session.
2. cd into your project path.
3. Tell the agent to use remote_* tools for all subsequent file/exec work, track host/project/connection state, and brief subagents to create their own connection.

To watch:

tmux attach -t remote-ssh-mcp/<host>

Ctrl-b w lists windows (one per active connection — parent + each subagent).

Agent config sync

The plugin also ships a remote-agent-config-sync skill for importing remote agent instructions into a local directory. It is meant for files such as AGENTS.md, CLAUDE.md, .agents/, .codex/, .claude/, .cursor/rules/, hooks, rules, and skills.

That workflow deliberately uses local rsync or scp -rp instead of adding generic transfer tools to the MCP API:

• remote_* tools stay focused on watchable remote coding work through tmux.
• rsync/scp handle bulk local/remote file movement better than base64 round-trips through a terminal pane.
• Adaptation happens only after files are copied locally. The remote config files are not modified by the sync workflow.
• Ambiguous hooks, install scripts, absolute paths, secrets, credentials, and destructive commands should be reviewed with the user before local adaptation.

Tools

All file/exec tools take a connection_id returned by remote_connect.

Tool	Local equivalent	Notes
remote_connect(host, project_path?, label?, agent_forwarding?, ssh_add_paths?)	—	Opens new tmux window. Returns {connection_id, host, cwd, agent_warning, forwarded_agent_present, ssh_add_paths, ssh_add_exit_code, ssh_add_output}.
remote_disconnect(connection_id)	—	Closes window. Closes session if last window.
remote_status()	—	Lists active connections.
remote_run(connection_id, cmd, timeout?)	Bash	Persistent shell. Returns {stdout, exit_code, duration_ms}.
remote_read(connection_id, path, offset?, limit?)	Read	Base64 round-trip through tmux. ≤1 MB.
remote_write(connection_id, path, content)	Write	Atomic via tempfile + rename.
remote_edit(connection_id, path, old, new, replace_all?)	Edit	Exact match, errors if old is non-unique unless replace_all=true.
remote_grep(connection_id, pattern, path?, glob?)	Grep	Uses rg if available, else grep -r.
remote_glob(connection_id, pattern, path?)	Glob	Uses find.

Troubleshooting

Couldn't connect to <host>. Check in this order:

1. ssh <host> works in a regular terminal (host is in ~/.ssh/config).
2. The host supports non-interactive key-based auth (BatchMode=yes).
3. If you need forwarded-agent operations from the remote host, local ssh-add can load your keys and agent forwarding is allowed.

agent_warning is present. The SSH connection worked, but the MCP server could not confirm a usable forwarded ssh-agent. Normal remote commands can still work through IdentityFile or other OpenSSH config. Private git fetches from the remote that rely on forwarded agent keys may fail. Pass agent_forwarding=false if you do not want the MCP server to run local ssh-add, connect with ssh -A, or check forwarded-agent readiness.

Explicit ssh_add_paths partially fail. remote_connect still proceeds if bulk ssh-add <paths...> returns non-zero. The response includes the expanded ssh_add_paths, ssh_add_exit_code, and ssh_add_output so the agent can tell you which requested paths may need checking before reconnecting.

The pane gets noisy with base64 blobs. Yes — that's the cost of routing file writes through the visible terminal. The skill prefixes blobs with a # remote-ssh-mcp: writing N bytes to <path> comment so it's at least labelled.

Subagents seem to share my window. The skill instructs subagents to call remote_connect themselves at task start. If they don't, they fall through to your window. Check the parent's prompt to subagents.

Limitations

• One pane per connection, serialized calls. Parallel calls on the same connection_id queue. Use separate connections (subagents) for parallelism, or nohup … & for true background work.
• Single remote_read calls are capped at ~1 MB. Read larger files in chunks with offset and limit; remote_edit chunks internally for UTF-8 text files.
• No built-in scp/rsync tools. Use the remote-agent-config-sync skill or local shell commands for bulk transfer; keep remote_* for remote project work.
• No interactive TUI driving. Things that need a TTY (vim, less in interactive mode, sudo password prompts) won't work cleanly. Use non-interactive equivalents.
• Binary file edits via remote_edit treat content as UTF-8 strings. For true binary edits, use remote_write with the full new content.

License

MIT — see LICENSE.