mcp-ssh-tool

Production-grade MCP SSH automation for operators, developers, and AI clients. mcp-ssh-tool opens persistent SSH sessions and exposes safe, structured tools for command execution, file operations, transfers, tunnels, package/service management, metrics, resources, and guided prompts.

v2 is secure by default: strict host-key verification is on, root login is off, raw sudo is policy-gated, destructive commands and filesystem mutations are denied unless policy allows them, and remote HTTP starts on loopback only unless bearer auth and allowed origins are configured.

Why This Server

• Trust: central policy engine, structured audit events, redacted logs, strict host keys, and machine-readable errors.
• MCP quality: stdio for local clients, Streamable HTTP for remote clients, legacy SSE only behind an explicit compatibility flag.
• AI-friendly tools: stable output schemas, structuredContent, annotations for read-only/destructive/idempotent behavior, resources, and curated prompts.
• Operations: session TTL/eviction, command timeouts, transfer checksum verification, real SSH forwarding, Prometheus metrics, and OpenTelemetry hooks.
• Portability: SFTP first, POSIX/BusyBox-aware shell fallbacks for basic file operations, and explicit support boundaries.

Quick Start

Run without installing:

npx -y mcp-ssh-tool --version

Or install globally:

pnpm add --global mcp-ssh-tool

Add a stdio MCP server to your client:

{
  "servers": {
    "ssh-mcp": {
      "type": "stdio",
      "command": "mcp-ssh-tool",
      "args": []
    }
  }
}

Use it from your MCP client:

Open a safe SSH session to prod-1 as deploy, inspect host capabilities, then show disk usage.

Requirements

• Node.js 22.22.2+ or 24.14.1+ (LTS only)
• SSH access to target hosts
• A populated known_hosts file for strict host verification, or an explicit per-session host-key policy

Transports

Mode	Command	Use When
stdio	mcp-ssh-tool	Local desktop clients such as ChatGPT, Claude Desktop, VS Code, Cursor, or Codex.
Streamable HTTP	mcp-ssh-tool --transport=http --host 127.0.0.1 --port 3000	Remote MCP clients, reverse proxies, or Inspector sessions.
legacy SSE	mcp-ssh-tool --transport=http --enable-legacy-sse	Temporary v1 compatibility only. Prefer Streamable HTTP.

Non-loopback HTTP startup is refused unless both --bearer-token-file and allowed origins are configured.

Secure Defaults

Area	v2 Default
Host keys	hostKeyPolicy=strict, knownHostsPath=~/.ssh/known_hosts
Root SSH login	denied
Raw proc_sudo	denied unless allowRawSudo=true
Destructive commands	denied unless allowDestructiveCommands=true
Destructive fs operations	allowed only under policy prefixes, denied elsewhere
Local transfer paths	file_upload and file_download limited to OS temp unless policy allows more
HTTP bind	127.0.0.1
Legacy SSE	disabled
File reads	size-limited by SSH_MCP_MAX_FILE_SIZE

Per-session policyMode: "explain" returns a plan/verdict without executing. Use it before mutations when an AI client needs to summarize risk.

Policy Example

Set SSH_MCP_POLICY_FILE=/etc/mcp-ssh-tool/policy.json:

{
  "mode": "enforce",
  "allowRootLogin": false,
  "allowRawSudo": false,
  "allowDestructiveCommands": false,
  "allowDestructiveFs": false,
  "allowedHosts": ["^prod-[0-9]+\\.example\\.com$"],
  "commandAllow": ["^(uname|df|uptime|systemctl status)\\b"],
  "commandDeny": ["rm\\s+-rf\\s+/", "shutdown", "reboot"],
  "pathAllowPrefixes": ["/tmp", "/var/tmp", "/home/deploy"],
  "pathDenyPrefixes": ["/etc/shadow", "/etc/sudoers", "/boot", "/dev", "/proc"],
  "localPathAllowPrefixes": ["/var/tmp/mcp-ssh-tool"],
  "localPathDenyPrefixes": []
}

Simple deploys can use environment overrides such as SSH_MCP_ALLOW_RAW_SUDO=true, SSH_MCP_ALLOWED_HOSTS=prod-1.example.com, SSH_MCP_PATH_ALLOW_PREFIXES=/tmp,/home/deploy, or SSH_MCP_LOCAL_PATH_ALLOW_PREFIXES=/var/tmp/mcp-ssh-tool.

Core Tools

• ssh_open_session, ssh_close_session, ssh_list_sessions, ssh_ping, ssh_list_configured_hosts, ssh_resolve_host
• proc_exec, proc_sudo, proc_exec_stream
• fs_read, fs_write, fs_list, fs_stat, fs_mkdirp, fs_rmrf, fs_rename
• file_upload, file_download
• ensure_package, ensure_service, ensure_lines_in_file, patch_apply
• os_detect, get_metrics
• tunnel_local_forward, tunnel_remote_forward, tunnel_list, tunnel_close

All tools return text plus stable structuredContent. Tool metadata includes titles, output schemas, and annotations that disclose read-only, destructive, idempotent, and external side-effect behavior.

Resources And Prompts

Resources:

• mcp-ssh-tool://sessions/active
• mcp-ssh-tool://metrics/json
• mcp-ssh-tool://metrics/prometheus
• mcp-ssh-tool://ssh-config/hosts
• mcp-ssh-tool://policy/effective
• mcp-ssh-tool://audit/recent
• mcp-ssh-tool://capabilities/support-matrix

Prompts:

• safe-connect
• inspect-host-capabilities
• plan-mutation
• managed-config-change

Support Matrix

Target	Status
Linux	Full support.
macOS/BSD	Session, process, fs, and transfer supported; package/service helpers only where tested.
BusyBox/dropbear	Experimental for session, process, and basic fs fallbacks.
Windows SSH targets	Experimental for session, process, fs, and transfer; no proc_sudo or ensure_*.

Client Examples

ChatGPT or Claude Desktop:

{
  "mcpServers": {
    "ssh-mcp": {
      "command": "npx",
      "args": ["-y", "mcp-ssh-tool"]
    }
  }
}

VS Code or Cursor:

{
  "servers": {
    "ssh-mcp": {
      "type": "stdio",
      "command": "mcp-ssh-tool"
    }
  }
}

MCP Inspector over HTTP:

printf '%s' 'super-secret-token' > .mcp-token
mcp-ssh-tool --transport=http --host 127.0.0.1 --port 3000 --bearer-token-file .mcp-token

Configuration

High-value environment variables:

Variable	Default	Purpose
SSH_MCP_POLICY_FILE	unset	Canonical JSON policy source.
SSH_MCP_HOST_KEY_POLICY	strict	strict, accept-new, or insecure.
SSH_MCP_KNOWN_HOSTS_PATH	~/.ssh/known_hosts	Known-hosts file for strict verification.
SSH_MCP_MAX_FILE_SIZE	10485760	Max bytes for fs_read.
SSH_MCP_COMMAND_TIMEOUT	30000	Default command timeout.
SSH_MCP_HTTP_HOST	127.0.0.1	Streamable HTTP bind host.
SSH_MCP_HTTP_PORT / PORT	3000	Streamable HTTP port.
SSH_MCP_HTTP_MAX_REQUEST_BODY_BYTES	1048576	Max JSON request bytes accepted by Streamable HTTP.
SSH_MCP_LOCAL_PATH_ALLOW_PREFIXES	OS temp directory	Local transfer allow-list for file_upload and file_download.
SSH_MCP_HTTP_BEARER_TOKEN_FILE	unset	Required for non-loopback HTTP.
SSH_MCP_HTTP_ALLOWED_ORIGINS	loopback origins	Comma-separated allowed origins.

Deprecated aliases STRICT_HOST_KEY_CHECKING and SSH_MCP_STRICT_HOST_KEY are still accepted for one v2 compatibility cycle. Prefer SSH_MCP_HOST_KEY_POLICY.

Development

Use the exact local runtime from .nvmrc / .node-version, then run:

pnpm install --frozen-lockfile
pnpm run check

Live SSH suites are opt-in:

RUN_SSH_INTEGRATION=1 pnpm run test:integration
RUN_SSH_E2E=1 pnpm run test:e2e

Local quality gates are layered:

• pre-commit: formats staged files and lints staged TypeScript only
• pre-push: runs pnpm run check:push
• task hooks: runs tracked pnpm hooks plus .pre-commit-config.yaml hooks when pre-commit is installed
• manual/full parity: task ci or pnpm run check

CI/CD Ownership

The organization repository https://github.com/oaslananka-lab/mcp-ssh-tool is the canonical source-of-truth. Automatic CI/CD, supply-chain security checks, trusted npm publishing, MCP Registry publishing, GitHub Releases, Docker image validation, SBOMs, attestations, and release decisions run only from the org repository.

The personal repository https://github.com/oaslananka/mcp-ssh-tool is a showcase mirror only. It must not contain publish workflows or require GitHub Actions for package or registry release authority. If the two repositories ever conflict, the org repository wins.

The npm package repository.url intentionally points at the org repository so npm provenance can verify that the published artifact came from the same GitHub Actions repository that built it.

The MCP Registry server name remains io.github.oaslananka/mcp-ssh-tool because it is already published and changing it would break existing users. Registry metadata points its repository/source at the org repository where the current official schema permits it.

See docs/ci-cd-topology.md for mirror, release, dry-run, and manual fallback guidance.

Documentation

• ARCHITECTURE.md
• SECURITY_DECISIONS.md
• MIGRATION.md
• docs/ci-cd-topology.md
• docs/development.md
• docs/release.md
• docs/publishing.md
• docs/npm-provenance.md
• docs/mcp-registry.md
• docs/chatgpt-app.md
• docs/doppler.md
• docs/operations.md
• docs/repository-operations.md
• docs/docker.md
• docs/client-configs.md
• docs/security/release-integrity.md
• docs/security/chatgpt-app-threat-model.md
• docs/security/ssh-threat-model.md
• docs/branch-protection.md
• docs/maintenance-policy.md
• docs/api-stability.md
• docs/threat-model.md
• docs/configuration.md
• docs/security-model.md
• docs/troubleshooting.md
• docs/enterprise-deployment.md

License

MIT License. See LICENSE.