MCP SSH Agent

A Model Context Protocol (MCP) server for managing and controlling SSH connections. This server integrates seamlessly with Claude Desktop and other MCP-compatible clients to provide AI-powered SSH operations.

Overview

This MCP server provides SSH operations through a clean, standardized interface that can be used by MCP-compatible language models like Claude Desktop. The server automatically discovers SSH hosts from your ~/.ssh/config and ~/.ssh/known_hosts files and executes commands using native SSH tools for maximum reliability.

Quick Start

Desktop Extension Installation (Recommended)

The easiest way to install MCP SSH Agent is through the Desktop Extension (.dxt) format:

1. Download the latest mcp-ssh-*.dxt file from the GitHub releases page
2. Double-click the .dxt file to install it in Claude Desktop
3. The SSH tools will be automatically available in your conversations with Claude

Alternative Installation Methods

Installation via npx

npx @aiondadotcom/mcp-ssh

Manual Claude Desktop Configuration

To use this MCP server with Claude Desktop using manual configuration, add the following to your MCP settings file:

On macOS: ~/Library/Application Support/Claude/claude_desktop_config.json On Windows: %APPDATA%/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "mcp-ssh": {
      "command": "npx",
      "args": ["@aiondadotcom/mcp-ssh"]
    }
  }
}

After adding this configuration, restart Claude Desktop. The SSH tools will be available for use in your conversations with Claude.

Global Installation

npm install -g @aiondadotcom/mcp-ssh

Local Development

git clone https://github.com/aiondadotcom/mcp-ssh.git
cd mcp-ssh
npm install
npm start

Example Usage

The screenshot above shows the MCP SSH Agent in action, demonstrating how it integrates with MCP-compatible clients to provide seamless SSH operations.

Integration with Claude

This screenshot demonstrates the MCP SSH Agent integrated with Claude, showing how the AI assistant can directly manage SSH connections and execute remote commands through the MCP protocol.

Key Features

• Reliable SSH: Uses native ssh/scp commands instead of JavaScript SSH libraries
• Automatic Discovery: Finds hosts from SSH config and known_hosts files
• Full SSH Support: Works with SSH agents, keys, and all authentication methods
• Password Authentication: Supports password-based SSH login and key passphrases via @password annotation — passwords never leave your machine
• File Operations: Upload and download files using scp
• Batch Commands: Execute multiple commands in sequence
• Error Handling: Comprehensive error reporting with timeouts

Functions

The agent provides the following MCP tools:

1. listKnownHosts() - Lists all known SSH hosts, prioritizing entries from ~/.ssh/config first, then additional hosts from ~/.ssh/known_hosts
2. runRemoteCommand(hostAlias, command) - Executes a command on a remote host using ssh
3. getHostInfo(hostAlias) - Returns detailed configuration for a specific host
4. checkConnectivity(hostAlias) - Tests SSH connectivity to a host
5. uploadFile(hostAlias, localPath, remotePath) - Uploads a file to the remote host using scp
6. downloadFile(hostAlias, remotePath, localPath) - Downloads a file from the remote host using scp
7. runCommandBatch(hostAlias, commands) - Executes multiple commands sequentially

Configuration Examples

Claude Desktop Integration

Here's how your Claude Desktop configuration should look:

{
  "mcpServers": {
    "mcp-ssh": {
      "command": "npx",
      "args": ["@aiondadotcom/mcp-ssh"]
    }
  }
}

Manual Server Configuration

If you prefer to run the server manually or integrate it with other MCP clients:

{
  "servers": {
    "mcp-ssh": {
      "command": "npx",
      "args": ["@aiondadotcom/mcp-ssh"]
    }
  }
}

Requirements

• Node.js 20 or higher
• SSH client installed (ssh and scp commands available)
• SSH configuration files (~/.ssh/config and ~/.ssh/known_hosts)

Usage with Claude Desktop

Once configured, you can ask Claude to help you with SSH operations like:

• "List all my SSH hosts"
• "Check connectivity to my production server"
• "Run a command on my web server"
• "Upload this file to my remote server"
• "Download logs from my application server"

Claude will use the MCP SSH tools to perform these operations safely and efficiently.

Usage

The agent runs as a Model Context Protocol server over STDIO. When installed via npm, you can use it directly:

# Run via npx (recommended)
npx @aiondadotcom/mcp-ssh

# Or if installed globally
mcp-ssh

# For development - run with debug output
npm start

The server communicates via clean JSON over STDIO, making it perfect for MCP clients like Claude Desktop.

Advanced Configuration

Environment Variables

• MCP_SILENT=true - Disable debug output (automatically set when used as MCP server)

SSH Configuration

The agent reads from standard SSH configuration files:

• ~/.ssh/config - SSH client configuration (supports Include directives)
• ~/.ssh/known_hosts - Known host keys

Make sure your SSH keys are properly configured and accessible via SSH agent or key files.

Password Authentication

For hosts that require password-based authentication (common with network infrastructure like switches and routers), you can store the password directly in your ~/.ssh/config using a special comment annotation:

Host myrouter
    HostName 192.168.1.1
    User admin
    # @password:yourSecretPassword

Host myserver
    HostName 10.0.0.5
    User deploy
    IdentityFile ~/.ssh/id_rsa
    # @password:myKeyPassphrase

How it works:

• The # @password: annotation is read locally by the MCP server — the password never reaches the AI model or any cloud provider
• Works for both login passwords and SSH key passphrases
• The password is split at the first :, so passwords containing : are supported
• When listing hosts, only passwordAuth: true is shown — the actual password is never exposed

Security requirements:

• Your SSH config file must have 600 permissions when using @password annotations
• The MCP server will refuse to start if the file permissions are too open
• Fix with: chmod 600 ~/.ssh/config

Include Directive Support

The MCP SSH Agent fully supports SSH Include directives to organize your configuration across multiple files. However, there's an important SSH bug to be aware of:

⚠️ SSH Include Directive Bug Warning

SSH has a configuration parsing bug where Include statements must be placed at the beginning of your ~/.ssh/config file to work correctly. If placed at the end, SSH will read them but won't properly apply the included configurations.

✅ Correct placement (at the beginning):

# ~/.ssh/config
Include ~/.ssh/config.d/*
Include ~/.ssh/work-hosts

# Global settings
ServerAliveInterval 55

# Host definitions
Host myserver
    HostName example.com

❌ Incorrect placement (at the end) - won't work:

# ~/.ssh/config
# Global settings
ServerAliveInterval 55

# Host definitions
Host myserver
    HostName example.com

# These Include statements won't work properly due to SSH bug:
Include ~/.ssh/config.d/*
Include ~/.ssh/work-hosts

The MCP SSH Agent correctly processes Include directives regardless of their placement in the file, so you'll get full host discovery even if SSH itself has issues with your configuration.

Example ~/.ssh/config

Here's an example SSH configuration file that demonstrates various connection scenarios including Include directives and @password annotations for password-based authentication:

# Include directives must be at the beginning due to SSH bug
Include ~/.ssh/config.d/*
Include ~/.ssh/work-servers

# Global settings - keep connections alive
ServerAliveInterval 55

# Production server with jump host
Host prod
    Hostname 203.0.113.10
    Port 22022
    User deploy
    IdentityFile ~/.ssh/id_prod_rsa

# Root access to production (separate entry)
Host root@prod
    Hostname 203.0.113.10
    Port 22022
    User root
    IdentityFile ~/.ssh/id_prod_rsa

# Router with password authentication (no SSH key)
Host router
    Hostname 192.168.1.1
    User admin
    # @password:cQbG0q@019TAoehZel7V

# Archive server accessed through production jump host
Host archive
    Hostname 2001:db8:1f0:cafe::1
    Port 22077
    User archive-user
    ProxyJump prod

# Web servers with specific configurations
Host web1.example.com
    Hostname 198.51.100.15
    Port 22022
    User root
    IdentityFile ~/.ssh/id_ed25519

Host web2.example.com
    Hostname 198.51.100.25
    Port 22022
    User root
    IdentityFile ~/.ssh/id_ed25519

# Database server with custom key and passphrase-protected key
Host database
    Hostname 203.0.113.50
    Port 22077
    User dbadmin
    IdentityFile ~/.ssh/id_database_rsa
    IdentitiesOnly yes
    # @password:U1Jqn=NoKdELYn&h1jVT

# Mail servers (password auth, no SSH key)
Host mail1
    Hostname 198.51.100.88
    Port 22078
    User mailuser
    # @password:7iBiV8lyoq*zANv46ALD

Host root@mail1
    Hostname 198.51.100.88
    Port 22078
    User root
    # @password:MRDHI2h!zhhN=ZJIxWzH

# Monitoring server
Host monitor
    Hostname 203.0.113.100
    Port 22077
    User monitoring
    IdentityFile ~/.ssh/id_monitor_ed25519
    IdentitiesOnly yes

# Load balancers
Host lb-a
    Hostname 198.51.100.200
    Port 22077
    User root

Host lb-b
    Hostname 198.51.100.201
    Port 22077
    User root

This configuration demonstrates:

• Global settings: ServerAliveInterval to keep connections alive
• Custom ports: Non-standard SSH ports for security
• Multiple users: Different user accounts for the same host (e.g., prod and root@prod)
• Jump hosts: Using ProxyJump to access servers through bastion hosts
• IPv6 addresses: Modern networking support
• Identity files: Specific SSH keys for different servers
• Security options: IdentitiesOnly yes to use only specified keys
• Password authentication: # @password: annotations for devices without SSH key support (e.g., routers, switches) or for passphrase-protected keys

How MCP SSH Agent Uses Your Configuration

The MCP SSH agent automatically discovers and uses your SSH configuration:

1. Host Discovery: All hosts from ~/.ssh/config are automatically available
2. Native SSH: Uses your system's ssh command, so all config options work
3. Authentication: Respects your SSH agent, key files, and authentication settings
4. Jump Hosts: Supports complex proxy chains and bastion host setups
5. Port Forwarding: Can work with custom ports and connection options

Example Usage with Claude Desktop:

• "List my SSH hosts" → Shows all configured hosts including prod, archive, web1.example.com, etc.
• "Connect to archive server" → Uses the ProxyJump configuration automatically
• "Run 'df -h' on web1.example.com" → Connects with the correct user, port, and key
• "Upload file to database server" → Uses the specific identity file and port configuration

Troubleshooting

Common Issues

1. Command not found: Ensure ssh and scp are installed and in your PATH
2. Permission denied: Check SSH key permissions and SSH agent
3. Host not found: Verify host exists in ~/.ssh/config or ~/.ssh/known_hosts
4. Connection timeout: Check network connectivity and firewall settings

Debug Mode

Run with debug output to see detailed operation logs:

# Enable debug mode
MCP_SILENT=false npx @aiondadotcom/mcp-ssh

SSH Key Setup Guide

For the MCP SSH Agent to work properly, you need to set up SSH key authentication. Here's a complete guide:

1. Creating SSH Keys

Generate a new SSH key pair (use Ed25519 for better security):

# Generate Ed25519 key (recommended)
ssh-keygen -t ed25519 -C "your-email@example.com"

# Or generate RSA key (if Ed25519 is not supported)
ssh-keygen -t rsa -b 4096 -C "your-email@example.com"

Important: When prompted for a passphrase, leave it empty (press Enter). The MCP SSH Agent cannot handle password-protected keys as it runs non-interactively.

Enter passphrase (empty for no passphrase): [Press Enter]
Enter same passphrase again: [Press Enter]

This creates two files:

• ~/.ssh/id_ed25519 (private key) - Keep this secret!
• ~/.ssh/id_ed25519.pub (public key) - This gets copied to servers

2. Installing Public Key on Remote Servers

Copy your public key to the remote server's authorized_keys file:

# Method 1: Using ssh-copy-id (easiest)
ssh-copy-id user@hostname

# Method 2: Manual copy
cat ~/.ssh/id_ed25519.pub | ssh user@hostname "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys"

# Method 3: Copy and paste manually
cat ~/.ssh/id_ed25519.pub
# Then SSH to the server and paste into ~/.ssh/authorized_keys

3. Server-Side SSH Configuration

To enable secure key-only authentication on your SSH servers, edit /etc/ssh/sshd_config:

# Edit SSH daemon configuration
sudo nano /etc/ssh/sshd_config

Add or modify these settings:

# Enable public key authentication
PubkeyAuthentication yes
AuthorizedKeysFile .ssh/authorized_keys

# Disable password authentication (security best practice)
PasswordAuthentication no
ChallengeResponseAuthentication no
UsePAM no

# Root login options (choose one):
# Option 1: Allow root login with SSH keys only (recommended for admin access)
PermitRootLogin prohibit-password

# Option 2: Completely disable root login (most secure, but less flexible)
# PermitRootLogin no

# Optional: Restrict SSH to specific users
AllowUsers deploy root admin

# Optional: Change default port for security
Port 22022

After editing, restart the SSH service:

# On Ubuntu/Debian
sudo systemctl restart ssh

# On CentOS/RHEL/Fedora
sudo systemctl restart sshd

# On macOS
sudo launchctl unload /System/Library/LaunchDaemons/ssh.plist
sudo launchctl load /System/Library/LaunchDaemons/ssh.plist

4. Setting Correct Permissions

SSH is very strict about file permissions. Set them correctly:

On your local machine:

chmod 700 ~/.ssh
chmod 600 ~/.ssh/id_ed25519
chmod 644 ~/.ssh/id_ed25519.pub
chmod 644 ~/.ssh/config
chmod 644 ~/.ssh/known_hosts

On the remote server:

chmod 700 ~/.ssh
chmod 600 ~/.ssh/authorized_keys

5. Testing SSH Key Authentication

Test your connection before using with MCP SSH Agent:

# Test connection
ssh -i ~/.ssh/id_ed25519 user@hostname

# Test with verbose output for debugging
ssh -v -i ~/.ssh/id_ed25519 user@hostname

# Test specific configuration
ssh -F ~/.ssh/config hostname

6. Multiple Keys for Different Servers

You can create different keys for different servers:

# Create specific keys
ssh-keygen -t ed25519 -f ~/.ssh/id_production -C "production-server"
ssh-keygen -t ed25519 -f ~/.ssh/id_staging -C "staging-server"

Then configure them in ~/.ssh/config:

Host production
    Hostname prod.example.com
    User deploy
    IdentityFile ~/.ssh/id_production
    IdentitiesOnly yes

Host staging
    Hostname staging.example.com
    User deploy
    IdentityFile ~/.ssh/id_staging
    IdentitiesOnly yes

Threat Model and Trust Boundaries

MCP SSH Agent gives an LLM the ability to drive ssh and scp on your behalf. Before using it, it is important to understand what an attacker who controls the LLM's instructions (for example via prompt injection through web pages, e‑mails, repository files, or another MCP server's output) can do:

• runRemoteCommand is full remote code execution on every host you have configured. If your ~/.ssh/config contains an entry for production, the LLM can run arbitrary commands as that user on that host. This is the tool's purpose, not a bug — but it means you should only configure hosts that you are willing to let the LLM touch, and prefer least-privilege accounts.
• uploadFile and downloadFile give the LLM access to the local filesystem with the privileges of the user running the MCP server. The LLM can read any file the process can read (including ~/.ssh/id_*, browser data, source trees, .env files) and write to any path it can write to (including ~/.ssh/authorized_keys). The path arguments are not sandboxed because the tool's contract is "transfer arbitrary files".
• The MCP server runs locally over STDIO, but the LLM is not trusted. STDIO only describes the transport — the content of tool arguments is chosen by the model, which can be steered by any untrusted text it ingests during the conversation.
• # @password: annotations are kept out of the LLM's context, but they live in ~/.ssh/config on disk. Anything that gives an attacker arbitrary local file read (see above) also exposes those passwords. The annotation only protects against the LLM seeing the password through the MCP protocol, not against local file disclosure.

Recommendations

• Run MCP SSH Agent under a dedicated, unprivileged OS user whose home directory only contains the SSH config and keys you actually want the LLM to be able to use.
• Or run it inside a container / sandbox with a minimal ~/.ssh and no access to other secrets on your machine.
• Keep ~/.ssh/config to the smallest set of hosts you trust the LLM with. Use restricted shell users on the remote side where possible.
• Treat any session where the LLM ingests untrusted content (web pages, e‑mails, third‑party repos, other MCP servers' output) as potentially hostile to MCP SSH operations.
• Report suspected vulnerabilities via GitHub's private vulnerability reporting on this repository.

Security Best Practices

SSH Key Security

• Never use password-protected keys with MCP SSH Agent
• Never share private keys - they should stay on your machine only
• Use Ed25519 keys when possible (more secure than RSA)
• Create separate keys for different environments/purposes
• Regularly rotate keys (every 6-12 months)

Server Security

• Disable password authentication completely
• Use non-standard SSH ports to reduce automated attacks
• Limit SSH access to specific users with AllowUsers
• Choose appropriate root login policy:
  • PermitRootLogin prohibit-password - Allows root access with SSH keys only (recommended for admin tasks)
  • PermitRootLogin no - Completely disables root login (most secure, but requires sudo access)
• Enable SSH key-only authentication for all accounts
• Consider using jump hosts for additional security layers

Network Security

• Use VPN or bastion hosts for production servers
• Implement fail2ban to block brute force attempts
• Monitor SSH logs regularly
• Use SSH key forwarding carefully (disable when not needed)

Building Desktop Extensions

For developers who want to build DXT packages locally:

Prerequisites

• Node.js 20 or higher
• npm

Building DXT Package

# Install dependencies
npm install

# Build the DXT package
npm run build:dxt

This creates a .dxt file in the build/ directory that can be installed in Claude Desktop.

Publishing DXT Releases

To publish a new DXT release:

# Build the DXT package
npm run build:dxt

# Create a GitHub release with the DXT file
gh release create v1.0.3 build/mcp-ssh-1.0.3.dxt --title "Release v1.0.3" --notes "MCP SSH Agent v1.0.3"

The DXT file will be available as a release asset for users to download and install.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT License - see LICENSE file for details.

Project Structure

mcp-ssh/
├── server.mjs          # Main MCP server implementation
├── manifest.json              # DXT package manifest
├── package.json               # Dependencies and scripts
├── README.md                  # Documentation
├── LICENSE                    # MIT License
├── CHANGELOG.md               # Release history
├── PUBLISHING.md              # Publishing instructions
├── start.sh                   # Development startup script
├── start-silent.sh            # Silent startup script
├── scripts/
│   └── build-dxt.sh           # DXT package build script
├── doc/
│   ├── example.png            # Usage example screenshot
│   └── Claude.png             # Claude Desktop integration example
└── doc/                       # Documentation assets

About

This project is maintained by aionda.com and provides a reliable bridge between AI assistants and SSH infrastructure through the Model Context Protocol.