ssh-mcp-server

SSH-based MCP (Model Context Protocol) server that allows remote execution of SSH commands via the MCP protocol.

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📝 Project Overview

ssh-mcp-server is a bridging tool that enables AI assistants and other applications supporting the MCP protocol to execute remote SSH commands through a standardized interface. This allows AI assistants to safely operate remote servers, execute commands, and retrieve results without directly exposing SSH credentials to AI models.

✨ Key Features

• 🔒 Secure Connections: Supports multiple secure SSH connection methods, including password authentication and private key authentication (with passphrase support)
• 🛡️ Command Security Control: Precisely control the range of allowed commands through flexible blacklist and whitelist mechanisms to prevent dangerous operations
• 🔄 Standardized Interface: Complies with MCP protocol specifications for seamless integration with AI assistants supporting the protocol
• 🚇 Dual Transport Modes: Supports both exec and shell transport modes for direct SSH hosts and bastion or jump-host scenarios
• 📂 File Transfer: Supports bidirectional file transfers, uploading local files to servers or downloading files from servers
• 🔑 Credential Isolation: SSH credentials are managed entirely locally and never exposed to AI models, enhancing security
• 🚀 Ready to Use: Can be run directly using NPX without global installation, making it convenient and quick to deploy

📦 Open Source Repository

GitHub: https://github.com/classfang/ssh-mcp-server

NPM: https://www.npmjs.com/package/@fangjunjie/ssh-mcp-server

🛠️ Tools List

Tool	Name	Description
execute-command	Command Execution Tool	Execute SSH commands on remote servers and get results
upload	File Upload Tool	Upload local files to specified locations on remote servers
download	File Download Tool	Download files from remote servers to local specified locations
list-servers	List Servers Tool	List all available SSH server configurations

📚 Usage

0. 🤖 Quick Setup via AI Skill (Recommended)

If you are using an AI coding assistant that supports skills (such as Claude Code), you can use the built-in ssh-mcp-helper skill to complete the installation and configuration interactively — no need to manually edit JSON files.

How to use:

1. Install the skill from this repository's skills/ directory
2. Tell your AI assistant: "Help me set up ssh-mcp-server" or "Configure SSH MCP for my remote server"
3. The skill will guide you step by step: check Node.js environment → choose MCP client → select authentication method → collect connection parameters → generate and write configuration

The skill supports all scenarios covered below (password, private key, SSH config reuse, SOCKS proxy, bastion hosts, multi-connection, 2FA, command restrictions, etc.) and automatically produces correctly formatted configuration.

---

The sections below are arranged from the simplest entry point (username + password) to more advanced scenarios. Pick the case that matches yours and copy the mcp.json snippet directly into your MCP client configuration.

⚠️ Important: In MCP configuration files, each command line argument and its value must be separate elements in the args array. Do NOT combine them with spaces. For example, use "--host", "192.168.1.1" instead of "--host 192.168.1.1".

1. 🔑 Username + Password (simplest)

{
  "mcpServers": {
    "ssh-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fangjunjie/ssh-mcp-server",
        "--host", "192.168.1.1",
        "--port", "22",
        "--username", "root",
        "--password", "pwd123456"
      ]
    }
  }
}

2. 🔐 Username + Private Key

{
  "mcpServers": {
    "ssh-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fangjunjie/ssh-mcp-server",
        "--host", "192.168.1.1",
        "--port", "22",
        "--username", "root",
        "--privateKey", "~/.ssh/id_rsa"
      ]
    }
  }
}

3. 🔏 Private Key with Passphrase

{
  "mcpServers": {
    "ssh-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fangjunjie/ssh-mcp-server",
        "--host", "192.168.1.1",
        "--port", "22",
        "--username", "root",
        "--privateKey", "~/.ssh/id_rsa",
        "--passphrase", "pwd123456"
      ]
    }
  }
}

4. 📋 Reuse ~/.ssh/config

If you already have a host alias in ~/.ssh/config, the server reads connection parameters directly from it — no need to repeat them in mcp.json.

{
  "mcpServers": {
    "ssh-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fangjunjie/ssh-mcp-server",
        "--host", "myserver"
      ]
    }
  }
}

Assuming your ~/.ssh/config contains:

Host myserver
    HostName 192.168.1.1
    Port 22
    User root
    IdentityFile ~/.ssh/id_rsa

You can also specify a custom SSH config file path:

{
  "mcpServers": {
    "ssh-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fangjunjie/ssh-mcp-server",
        "--host", "myserver",
        "--ssh-config-file", "/path/to/custom/ssh_config"
      ]
    }
  }
}

Note: Command-line parameters take precedence over SSH config values. For example, if you specify --port 2222, it will override the port from SSH config.

5. 🌐 Connecting Through a Proxy

When the target host is only reachable through a proxy, use --proxy with a SOCKS5, HTTP, or HTTPS proxy.

{
  "mcpServers": {
    "ssh-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fangjunjie/ssh-mcp-server",
        "--host", "192.168.1.1",
        "--port", "22",
        "--username", "root",
        "--password", "pwd123456",
        "--proxy", "http://username:password@proxy-host:proxy-port"
      ]
    }
  }
}

Supported URL formats:

socks://username:password@proxy-host:1080
socks5://username:password@proxy-host:1080
http://username:password@proxy-host:8080
https://username:password@proxy-host:8443

HTTP and HTTPS proxies use the CONNECT method to tunnel to the SSH server, with optional Basic proxy authentication. HTTP and HTTPS default to ports 80 and 443; SOCKS5 requires an explicit port. HTTPS proxy certificates are verified using the default Node.js trust store.

The existing socksProxy configuration and --socksProxy option remain supported for backward compatibility, but only accept socks:// and socks5://. Do not configure both proxy and socksProxy.

6. 📝 Restricting Commands With Whitelist / Blacklist

Use --whitelist and --blacklist to limit which commands the server is allowed to run. Patterns are comma-separated regular expressions. Strongly recommended for any production use.

Whitelist example (only allow read-only inspection commands):

{
  "mcpServers": {
    "ssh-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fangjunjie/ssh-mcp-server",
        "--host", "192.168.1.1",
        "--port", "22",
        "--username", "root",
        "--password", "pwd123456",
        "--whitelist", "^ls( .*)?,^cat .*,^df.*"
      ]
    }
  }
}

Blacklist example (block destructive commands):

{
  "mcpServers": {
    "ssh-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fangjunjie/ssh-mcp-server",
        "--host", "192.168.1.1",
        "--port", "22",
        "--username", "root",
        "--password", "pwd123456",
        "--blacklist", "^rm .*,^shutdown.*,^reboot.*"
      ]
    }
  }
}

Note: If both whitelist and blacklist are specified, the command must pass both checks (whitelist first, then blacklist) to be executed.

7. 🧩 Wrapping Commands With a Template

commandTemplate wraps every executed command in a template — useful for switching user via su, running inside a container, or jumping through another host. Use <quotedCommand> when the command is passed as a shell argument, or <command> for raw insertion. The template is applied after the working-directory cd is prepended, so the entire cd ... && <actual command> chain gets wrapped.

{
  "mcpServers": {
    "ssh-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fangjunjie/ssh-mcp-server",
        "--host", "10.0.0.1",
        "--port", "22",
        "--username", "deploy",
        "--password", "xxx",
        "--command-template", "su root -c <quotedCommand>"
      ]
    }
  }
}

Executing ls /app with directory /data actually sends:

su root -c 'cd -- '\''/data'\'' && ls /app'

Other useful templates:

sudo bash -c <quotedCommand>
docker exec -i mycontainer sh -c <quotedCommand>
ssh jumphost <quotedCommand>

8. 🚇 Bastion / Jump Host (transportMode: shell)

transportMode defaults to exec. Switch to shell when:

• SSH login succeeds but exec command execution fails
• The remote side requires shell startup scripts, banners, or environment initialization first
• The target effectively exposes only an interactive shell (bastion hosts, jump hosts, network devices)

Behavior differences:

• exec: supports execute-command, upload, and download
• shell: runs commands through a persistent shell session with an internal command queue, but does not support upload / download because SFTP is unavailable in this mode

{
  "mcpServers": {
    "ssh-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fangjunjie/ssh-mcp-server",
        "--host", "bastion.example.com",
        "--port", "22",
        "--username", "ops",
        "--password", "pwd123456",
        "--transport-mode", "shell",
        "--shell-ready-timeout", "15000"
      ]
    }
  }
}

In JSON config files you can also set shellCommandTimeoutMs to override the default per-command timeout for shell-backed connections.

9. 🔐 Multi-Factor Authentication (2FA / MFA)

When the SSH server requires multi-factor authentication (password + private key + 2FA verification code), enable tryKeyboard. The password and private key are auto-supplied. For non-password prompts, set SSH_MCP_2FA_CODE in the server environment before connecting.

{
  "mcpServers": {
    "ssh-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fangjunjie/ssh-mcp-server",
        "--host", "example.com",
        "--port", "22",
        "--username", "user",
        "--password", "your_password",
        "--privateKey", "/path/to/key",
        "--try-keyboard"
      ]
    }
  }
}

Authentication flow:

1. Private key authentication (if provided)
2. Password authentication (if provided)
3. Keyboard-interactive for 2FA code via SSH_MCP_2FA_CODE

10. 🧩 Managing Multiple SSH Connections

When you need to expose more than one SSH target through the same MCP server, register them under unique connection names and select the target at call time via connectionName. There are three ways to configure them:

📄 Method 1: Using Config File (Recommended)

Create a JSON configuration file (e.g., ssh-config.json):

Array Format:

[
  {
    "name": "dev",
    "host": "1.2.3.4",
    "port": 22,
    "username": "alice",
    "password": "{abc=P100s0}",
    "socksProxy": "socks://127.0.0.1:10808",
    "commandTimeoutMs": 120000,
    "maxOutputBytes": 10485760
  },
  {
    "name": "bastion",
    "host": "9.9.9.9",
    "port": 22,
    "username": "ops",
    "password": "pwd123456",
    "transportMode": "shell",
    "shellReadyTimeoutMs": 15000,
    "shellCommandTimeoutMs": 45000,
    "connectionTimeoutMs": 30000,
    "keepaliveIntervalMs": 10000,
    "keepaliveCountMax": 3
  },
  {
    "name": "prod",
    "host": "5.6.7.8",
    "port": 22,
    "username": "bob",
    "password": "yyy",
    "socksProxy": "socks://127.0.0.1:10808"
  },
  {
    "name": "secure-server",
    "host": "secure.example.com",
    "port": 22,
    "username": "admin",
    "password": "your_password",
    "privateKey": "/path/to/private/key",
    "tryKeyboard": true
  }
]

Object Format:

{
  "dev": {
    "host": "1.2.3.4",
    "port": 22,
    "username": "alice",
    "password": "{abc=P100s0}",
    "socksProxy": "socks://127.0.0.1:10808",
    "commandTimeoutMs": 120000,
    "maxOutputBytes": 10485760
  },
  "bastion": {
    "host": "9.9.9.9",
    "port": 22,
    "username": "ops",
    "password": "pwd123456",
    "transportMode": "shell",
    "shellReadyTimeoutMs": 15000,
    "shellCommandTimeoutMs": 45000
  },
  "prod": {
    "host": "5.6.7.8",
    "port": 22,
    "username": "bob",
    "password": "yyy",
    "socksProxy": "socks://127.0.0.1:10808"
  }
}

Then use the --config-file parameter:

{
  "mcpServers": {
    "ssh-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fangjunjie/ssh-mcp-server",
        "--config-file", "ssh-config.json"
      ]
    }
  }
}

🔧 Method 2: Using JSON Format with --ssh Parameter

You can pass JSON-formatted configuration strings directly:

{
  "mcpServers": {
    "ssh-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fangjunjie/ssh-mcp-server",
        "--ssh", "{\"name\":\"dev\",\"host\":\"1.2.3.4\",\"port\":22,\"username\":\"alice\",\"password\":\"{abc=P100s0}\",\"socksProxy\":\"socks://127.0.0.1:10808\"}",
        "--ssh", "{\"name\":\"bastion\",\"host\":\"9.9.9.9\",\"port\":22,\"username\":\"ops\",\"password\":\"pwd123456\",\"transportMode\":\"shell\",\"shellReadyTimeoutMs\":15000}",
        "--ssh", "{\"name\":\"prod\",\"host\":\"5.6.7.8\",\"port\":22,\"username\":\"bob\",\"password\":\"yyy\",\"socksProxy\":\"socks://127.0.0.1:10808\"}"
      ]
    }
  }
}

📝 Method 3: Legacy Comma-Separated Format (Backward Compatible)

For simple cases without special characters in passwords, you can still use the legacy format:

npx @fangjunjie/ssh-mcp-server \
  --ssh "name=dev,host=1.2.3.4,port=22,user=alice,password=xxx" \
  --ssh "name=prod,host=5.6.7.8,port=22,user=bob,password=yyy"

⚠️ Note: The legacy format may have issues with passwords containing special characters like =, ,, {, }. Use Method 1 or Method 2 for passwords with special characters.

In MCP tool calls, specify the connection name via the connectionName parameter. If omitted, the default connection is used.

Example (execute command on 'prod' connection):

{
  "tool": "execute-command",
  "params": {
    "cmdString": "ls -al",
    "connectionName": "prod"
  }
}

Example (execute command with timeout options):

{
  "tool": "execute-command",
  "params": {
    "cmdString": "ping -c 10 127.0.0.1",
    "connectionName": "prod",
    "timeout": 5000
  }
}

⏱️ Command Execution Timeout

The execute-command tool supports timeout options to prevent commands from hanging indefinitely:

• timeout: Per-call command execution timeout in milliseconds (optional); when provided, it overrides the connection setting, otherwise the connection setting or its 30000ms default is used
• Set commandTimeoutMs per connection in the JSON config file to change that default, so callers do not have to pass timeout on every call (exec mode)
• The shell mode equivalent is shellCommandTimeoutMs
• A timeout passed with the call always takes precedence over both settings
• Connections use SSH keepalives by default (keepaliveIntervalMs: 10000, keepaliveCountMax: 3) and respect connectionTimeoutMs for connection setup
• SFTP open and transfer operations respect sftpTimeoutMs (default 300000ms)
• Error responses include stable code, message, and retriable fields for easier agent-side handling

This is particularly useful for commands like ping, tail -f, or other long-running processes that might block execution.

📦 Command Output Limit

The combined captured stdout and stderr for each command is limited to protect the MCP server from large files or unbounded output:

• Set maxOutputBytes in a JSON connection configuration; the default is 10485760 bytes (10 MiB)
• maxOutputBytes must be a non-negative integer; 0 disables the limit, which is not recommended for untrusted commands
• When output exceeds the limit, the remote command is aborted and the tool returns an OUTPUT_LIMIT_EXCEEDED error with the captured, truncated output instead of reporting success
• With pty: false, warnings and progress written to stderr by successful commands are preserved in a [stderr] section
• The limit applies to both exec and shell mode. exec mode closes just that command's channel, whereas the shell channel is shared by every command on the connection and the remote keeps writing after an abort, so the connection is dropped instead — the same way a shell mode command timeout behaves

🗂️ List All SSH Servers

You can use the MCP tool list-servers to get all available SSH server configurations:

Example call:

{
  "tool": "list-servers",
  "params": {}
}

Example response:

[
  { "name": "dev", "host": "1.2.3.4", "port": 22, "username": "alice" },
  { "name": "prod", "host": "5.6.7.8", "port": 22, "username": "bob" }
]

⚙️ Command Line Options Reference

Options:
  --config-file       JSON configuration file path (recommended for multiple servers)
  --ssh-config-file   SSH config file path (default: ~/.ssh/config)
  --ssh               SSH connection configuration (can be JSON string or legacy format)
  -h, --host          SSH server host address or alias from SSH config
  -p, --port          SSH server port
  -u, --username      SSH username
  -w, --password      SSH password
  -k, --privateKey    SSH private key file path
  -P, --passphrase    Private key passphrase (if any)
  -a, --agent         SSH agent socket path
  --try-keyboard      Enable keyboard-interactive authentication for 2FA/MFA (default: false)
  -W, --whitelist     Command whitelist, comma-separated regular expressions
  -B, --blacklist     Command blacklist, comma-separated regular expressions
  --proxy             Proxy URL supporting SOCKS5, HTTP, and HTTPS
  -s, --socksProxy    Legacy SOCKS5 proxy URL
  --allowed-local-paths   Additional allowed local paths for upload/download, comma-separated
  --allowed-remote-paths  Allowed remote (POSIX, absolute) paths for SFTP upload/download, comma-separated
  --transport-mode    SSH transport mode: exec or shell (default: exec)
  --shell-ready-timeout   Shell readiness probe timeout in milliseconds (default: 10000)
  --command-template  Command template, use <quotedCommand> for shell arguments or <command> for raw insertion
  --pty               Allocate pseudo-tty for command execution (default: true)
  --pre-connect       Pre-connect to all configured SSH servers on startup
  --version, -v       Print package version
  --help              Print this help message

🛡️ Security Considerations

This server provides powerful capabilities to execute commands and transfer files on remote servers. To ensure it is used securely, please consider the following:

• Command Whitelisting: It is strongly recommended to use the --whitelist option to restrict the set of commands that can be executed. Without a whitelist, any command can be executed on the remote server, which can be a significant security risk.
• Private Key Security: The server reads the SSH private key into memory. Ensure that the machine running the ssh-mcp-server is secure. Do not expose the server to untrusted networks.
• Denial of Service (DoS): The server does not have built-in rate limiting. An attacker could potentially launch a DoS attack by flooding the server with connection requests or large file transfers. It is recommended to run the server behind a firewall or reverse proxy with rate-limiting capabilities.
• Path Traversal: The server has built-in protection against path traversal attacks on the local filesystem. However, it is still important to be mindful of the paths used in upload and download commands.
• Local Transfer Scope: By default, local file transfers are restricted to the current working directory. Use --allowed-local-paths or allowedLocalPaths in config only for explicitly trusted directories.
• Remote Transfer Scope: SFTP upload/download accepts only absolute POSIX paths. If allowedRemotePaths (or --allowed-remote-paths) is not configured, any remote path is accepted and the server prints a startup warning. Configure allowedRemotePaths to whitelist a small set of remote directories; this is strongly recommended to prevent prompt-injection-driven reads or writes of files like ~/.ssh/authorized_keys or /etc/sshd_config.

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