SSH Client MCP Server

SSH Client MCP Server is a local Model Context Protocol (MCP) server that lets LLMs and other MCP clients execute shell commands on remote hosts over SSH. It runs from Linux, macOS, or Windows and targets any reachable SSH server (Linux, macOS, Windows with OpenSSH, etc.).

Built on somamcp — a functional MCP framework over FastMCP with telemetry, introspection, and backend abstraction.

Contents

• Quick Start
• Features
• Tools
• Installation
• Configuration
• Client Setup
• Testing
• Development
• Disclaimer

Quick Start

1. Configure your MCP client (Claude Desktop, Cursor, Cline, etc.) to launch this server via npx — see Client Setup.
2. Ask your LLM to run shell commands on the target host.

No global install required — npx fetches and runs the latest published version.

Features

• Single `exec` tool — runs a shell command on the remote host, returns stdout. stderr surfaces as a structured error.
• Four auth modes — password, key file, key from environment variable (e.g. injected by envpkt, Vault, Doppler), or SSH_AUTH_SOCK (system ssh-agent, 1Password, Bitwarden Desktop, KeePassXC).
• Smart path expansion — --key supports ~, $VAR, ${VAR}, and relative paths via functype-os. Unresolved variables fail fast with a typed error.
• OS-user fallback — --user defaults to the current OS username when omitted.
• Fail-fast auth — the SSH key is loaded and validated at server startup, not on the first exec call.
• Introspection out-of-the-box — soma_health, soma_capabilities, soma_connections auto-registered by somamcp.
• Cross-platform — runs on Linux, macOS, Windows (anywhere Node 22+ runs).

Tools

Persistent sessions (tmux)

For driving long-running interactive processes (e.g. a remote coding agent) across calls, the server exposes tmux-backed tools. tmux must be installed on the remote host.

• tmux_list — list live tmux sessions.
• tmux_send({ session?, input, submit? }) — type input into session (created if absent); presses Enter unless submit: false.
• tmux_read({ session?, lines? }) — return the recent pane transcript (lines default 200, max 2000).
• tmux_keys({ session?, keys }) — send control/special keys, e.g. { keys: ["C-c"] }.

session defaults to --tmux-session (default agent). Tip: run agents in a line-oriented mode (not a full-screen TUI) so tmux_read returns a clean transcript.

Installation

Run via npx (recommended)

No install step — your MCP client launches it on demand. See Client Setup.

Global install

npm install -g ssh-client-mcp-server
# then:
ssh-client-mcp-server --host=1.2.3.4 --user=root --password=pass

From source (for contributors)

git clone https://github.com/jordanburke/ssh-client-mcp-server.git
cd ssh-client-mcp-server
pnpm install
pnpm build

Configuration

The server reads SSH connection info from CLI flags:

\*Auth precedence is --password → --key → --key-env → --agent. If none are set the server starts but ssh2 will fail to authenticate on first exec.

Pulling keys from a password manager (Bitwarden / 1Password / KeePassXC)

Each of these can expose your SSH keys via SSH_AUTH_SOCK. Unlock the vault, confirm the agent is enabled, then run with --agent=true — the server never sees the private key.

# verify the agent is reachable
ssh-add -l

# launch the MCP server through it
ssh-client-mcp-server --host=1.2.3.4 --user=root --agent=true

For Bitwarden Desktop ≥ 2024.12: enable Settings → SSH agent, then on macOS confirm launchctl getenv SSH_AUTH_SOCK points at Bitwarden's socket.

Pulling keys from envpkt (or any tool that injects env vars)

Store the PEM as a sealed value in envpkt.toml, then launch via envpkt exec:

envpkt exec -- ssh-client-mcp-server --host=1.2.3.4 --user=root --key-env=MY_SSH_KEY

Same pattern works for HashiCorp Vault, Doppler, Infisical, AWS Secrets Manager, or any wrapper that lands the key in process.env.

Client Setup

Claude Desktop (claude_desktop_config.json)

{
  "mcpServers": {
    "ssh-client-mcp-server": {
      "command": "npx",
      "args": ["-y", "ssh-client-mcp-server", "--host=1.2.3.4", "--user=root", "--key=~/.ssh/id_ed25519"]
    }
  }
}

Password auth

Replace the --key arg with --password=hunter2. Avoid checking this into version control.

Using the current OS user

Omit --user entirely — the server defaults to your local username.

Other MCP clients

Any client that speaks the stdio MCP transport works. Same command / args shape.

Testing

Against a published build

npx @modelcontextprotocol/inspector npx ssh-client-mcp-server --host=1.2.3.4 --user=root --key=~/.ssh/id_ed25519

Against a local build (after pnpm build)

pnpm inspect

This builds and launches the MCP Inspector pointed at dist/index.js.

Development

All tooling is delegated to ts-builds:

pnpm validate      # format → lint → typecheck → test → build
pnpm test          # vitest run
pnpm test:watch    # vitest watch mode
pnpm build         # production build to dist/
pnpm dev           # tsdown watch mode to lib/
pnpm inspect       # build + launch MCP Inspector

Pure helpers (parseArgv, validateConfig, resolveAuth, effectiveUser) live in src/config.ts and are covered by test/config.spec.ts (18 cases, including tempfile-backed key reads and env-var expansion).

Disclaimer

Provided under the MIT License. Use at your own risk. Not affiliated with or endorsed by any SSH vendor or MCP provider. Be careful granting LLMs shell access — audit commands, restrict target-account privileges, and consider a jump box.

Contributing

Issues and PRs welcome at jordanburke/ssh-client-mcp-server. Please run pnpm validate before submitting.