host-terminal-mcp 0.2.2

MCP server for executing terminal commands on the host machine with configurable permissions

Host Terminal MCP

An MCP server that lets AI assistants run terminal commands on your machine with permission controls. Built for Claude Desktop / Co-work and any MCP-compatible client.

How It Works

You (in Co-work)                      Your Mac
─────────────────                     ─────────
"run git status"
      │
      ▼
Claude (cloud)
      │  MCP tool call:
      │  execute_command("git status")
      ▼
Claude Desktop (local)
      │  forwards via stdio pipe
      ▼
host-terminal-mcp                     ◄── this project
      │  1. permission check ✅
      │  2. /bin/bash -c "git status"
      ▼
Terminal output flows back up the chain

Claude Desktop spawns host-terminal-mcp as a child process and communicates over stdin/stdout using the MCP protocol. There is no network server involved — it's a local pipe.

Setup for Co-work

1. Install

uv tool install host-terminal-mcp

Or with pip:

pip install host-terminal-mcp

2. Configure Claude Desktop

Add the MCP server to your Claude Desktop config file:

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

Important: Claude Desktop runs with a minimal PATH (/usr/local/bin, /usr/bin, /bin, /usr/sbin, /sbin, /opt/homebrew/bin). If you installed with uv tool install or pip install --user, the binary is likely in ~/.local/bin/ which is not in Claude Desktop's PATH. Use the full absolute path to the binary to avoid "No such file or directory" errors.

Find your binary path:

which host-terminal-mcp
# Example output: /Users/you/.local/bin/host-terminal-mcp

Then use that path in the config:

{
  "mcpServers": {
    "host-terminal": {
      "command": "/Users/you/.local/bin/host-terminal-mcp"
    }
  }
}

To start in ask mode (recommended — prompts you before running unlisted commands):

{
  "mcpServers": {
    "host-terminal": {
      "command": "/Users/you/.local/bin/host-terminal-mcp",
      "args": ["--mode", "ask"]
    }
  }
}

Tip: If you installed globally to a system path (e.g. /usr/local/bin/host-terminal-mcp), you can use just "command": "host-terminal-mcp" without the full path.

3. Restart Claude Desktop

Quit and reopen Claude Desktop. It will automatically spawn the host-terminal-mcp process. You can verify it's running:

ps aux | grep host-terminal-mcp

4. Use it

Open a Co-work session in Claude.ai (or use Claude Desktop directly) and ask:

• "List files in my home directory"
• "Show git status in ~/projects/myapp"
• "What's running on port 3000?"
• "Run the tests for this project"

Permission Modes

Mode	Behavior	Safety
allowlist (default)	Only pre-approved read-only commands run	Safest
ask	Prompts you for approval on unlisted commands	Recommended for power users
allow_all	Everything runs except blocked commands	Dangerous

How ask Mode Works

When Claude tries to run a command not in the allow list, the server uses MCP elicitation to prompt you (the human) directly in the Claude Desktop UI:

┌─────────────────────────────────────────────┐
│ The AI wants to run a command that is not   │
│ in the allow list:                          │
│                                             │
│   npm install                               │
│                                             │
│ Do you approve?                             │
│                                             │
│ [✓] Approve this command?                   │
│ [✓] Add to allowed list permanently?        │
│                                             │
│         [ Cancel ]  [ Submit ]              │
└─────────────────────────────────────────────┘

• Approve — runs the command for this session
• Add to allowed list permanently — saves the command to your config file so you're never asked again
• Cancel/Decline — command is blocked

This is a real human-in-the-loop: Claude cannot approve commands on its own.

Note: Elicitation requires MCP client support. If your client doesn't support it, unlisted commands are rejected with a message telling you to add them to the config file.

Permission check order: blocked (always wins) > allowed > session-approved > mode decision

Default Allowed Commands

These commands (and their arguments) are allowed out of the box:

File listing & navigation: ls, ll, la, pwd, tree, find, locate, which, whereis, file

File viewing: cat, head, tail, less, more, bat, wc

Search: grep, rg, ag, ack, fzf

Git (read-only): git status, git log, git diff, git show, git branch, git remote, git tag, git stash list, git rev-parse, git config --get, git config --list, git blame, git shortlog, git describe

System info: uname, hostname, whoami, id, date, uptime, df, du, free, top -l 1, ps

Network (read-only): ping -c, curl -I, curl --head, dig, nslookup, host, ifconfig, ip addr, netstat, ss

Package managers (info only): npm list, npm ls, npm view, npm show, npm outdated, pip list, pip show, pip freeze, brew list, brew info, apt list, dpkg -l

Dev tool versions: python --version, python3 --version, node --version, npm --version, cargo --version, rustc --version, go version, java --version, javac --version, ruby --version, docker --version

Docker (read-only): docker ps, docker images, docker logs

Data processing: jq, yq

Misc: man, help, type, stat, md5sum, sha256sum, shasum

Always Blocked Commands

These are blocked regardless of permission mode:

Pattern	Reason
rm -rf /, rm -rf ~, rm -rf *	Recursive delete
mkfs, dd	Format/overwrite disk
find ... -exec	Arbitrary command execution
:(){	Fork bomb
> /dev/sd*	Overwrite disk device
chmod -R 777 /, chown -R	Dangerous permission changes
sudo, su, doas	Privilege escalation
reboot, shutdown, halt, poweroff	System control
kill, killall, pkill	Process control
nc -l, nmap	Network attacks
*/.ssh/, */.aws/, */.gnupg/	Sensitive credential access
/etc/shadow, /etc/passwd	System file access
history -c, shred	History/credential wiping

Configuration

Config file: ~/.config/host-terminal-mcp/config.yaml

# Generate a default config file
host-terminal-mcp --init-config

Add custom allowed commands

allowed_commands:
  - pattern: "docker compose logs"
    description: "Docker Compose service logs"
  - pattern: "docker compose ps"
    description: "Docker Compose service status"
  - pattern: "npm install"
    description: "Install npm packages"

  # Use regex for flexible matching
  - pattern: "^kubectl get "
    description: "Kubernetes get resources"
    is_regex: true

Other options

permission_mode: allowlist          # allowlist | ask | allow_all
timeout_seconds: 300                # Max command execution time
max_output_size: 100000             # Max output chars (truncated beyond this)
shell: /bin/bash                    # Shell to use
allowed_directories:                # Commands restricted to these dirs
  - /Users/me
environment_passthrough:            # Env vars passed to commands
  - PATH
  - HOME
  - USER
  - LANG
  - LC_ALL

HTTP Transport

For external services (e.g. a chatbot in Docker) that need to call your machine over the network:

# Install with HTTP extras
uv tool install 'host-terminal-mcp[http]'

# Start
host-terminal-mcp --http --port 8099

# Or in background
nohup host-terminal-mcp --http --port 8099 --mode ask > /tmp/host-terminal-mcp.log 2>&1 &

Endpoints

Endpoint	Method	Purpose
/health	GET	Health check
/execute	POST	Run a command
/cd	POST	Change working directory
/cwd	GET	Get current directory
/permissions	GET	Get permission config

Example

curl -X POST http://localhost:8099/execute \
  -H "Content-Type: application/json" \
  -d '{"command": "docker compose ps", "working_directory": "/path/to/project"}'

Architecture

src/host_terminal_mcp/
├── server.py        ← MCP stdio server, tool handlers, elicitation
├── http_server.py   ← Alternative HTTP/REST transport (FastAPI)
├── config.py        ← Permission rules, allowlist/blocklist, YAML config
└── executor.py      ← Runs commands via asyncio subprocess

Tools exposed to the AI:

Tool	Description
execute_command	Run a shell command (main tool)
change_directory	Change working directory
get_current_directory	Get current working directory
get_permission_status	Inspect current permissions
set_permission_mode	Change permission mode

Development

git clone https://github.com/ankitag-in/host-terminal-mcp.git
cd host-terminal-mcp
make install        # Install all deps (venv auto-created)
make test           # Run tests
make lint           # Run linters
make format         # Format code
make run            # Run stdio server (foreground)
make run MODE=ask   # Run in ask mode
make inspect        # Test with MCP Inspector
make help           # Show all targets

From source with Claude Desktop

{
  "mcpServers": {
    "host-terminal": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/host-terminal-mcp", "host-terminal-mcp"]
    }
  }
}

License

Apache-2.0