local-env-mcp

A stateless, Dockerized Model Context Protocol (MCP) server built with TypeScript. It exposes your local machine — filesystem, git, shell, network, databases, and system — to any MCP-compatible LLM client over HTTP.

Built natively in TypeScript on the @modelcontextprotocol/sdk utilizing Express, Zod schemas, and a fully decoupled, layered architecture.

Quick Start

# 1. Clone and install
git clone <repo-url>
cd local-mcp
npm install

# 2. Build the TypeScript source
npm run build

# 3. Start the server (runs on port 3000 by default)
npm start

# OR Start with Docker (multi-stage build)
docker compose up -d --build

# 4. Expose via ngrok (in a separate terminal)
ngrok http 3001

# 5. Copy the ngrok URL and add to Claude.ai
# Settings → Integrations → Add MCP Server
# URL: https://your-ngrok-url.ngrok-free.app/mcp

Table of Contents

• local-env-mcp
  • Architecture
  • Project Structure
  • Transport & Session Model
  • Tool Reference
    • 📁 Filesystem
    • 🌿 Git
    • 🌐 Network
    • 💻 Shell
    • 🖥️ System
    • 🐘 Postgres
  • Environment Variables
  • Extending with New Tools
  • Security Model

Architecture

LLM Client (Claude / Cursor / API)
        │  HTTPS POST /mcp
        ▼
   Express Routing Layer (src/app.ts)
        │
        ├── GET  /health → System Checks
        ├── POST /mcp    → Create Server Session
        ├── GET  /mcp    → Resume Session
        └── DELETE /mcp  → Purge Session
               │
               ▼
   Layered Tool Registry (src/tools/registry.ts)
               │
 ┌─────────┬───┴─────┬─────────┬─────────┬─────────┐
 ▼         ▼         ▼         ▼         ▼         ▼
 FS       Git      Network   Shell     System    Postgres
(9)      (11)       (8)       (9)       (8)       (3)

Stateless Mode: Each POST request spins up a fresh McpServer instance dynamically managed by a singleton Session Manager.

Project Structure

Migrated from legacy monolithic JS, the project now follows a strictly typed layered framework:

local-mcp/
├── src/
│   ├── server.ts               # Listener & bootstrap
│   ├── app.ts                  # Express routing & middleware wiring
│   ├── config.ts               # Zod-validated env loader (.env handled via dotenv)
│   ├── logger.ts               # Winston configuration
│   ├── routes/                 # Separated Controllers (health.ts, mcp.ts)
│   ├── services/               # Core Logic (processManager, sessionManager)
│   ├── types/                  # Shared TS definitions
│   └── tools/                  # All 48 MCP Tools separated by domain
│       ├── filesystem/         
│       ├── git/                
│       ├── network/            
│       ├── postgres/           # Dynamic Database capabilities
│       ├── shell/              
│       ├── system/             
│       └── registry.ts         # Injects toolsets into active MCP Sessions

Transport & Session Model

Uses the Streamable HTTP transport.

| Route | Purpose | |---|---| | POST /mcp | Initiates tool requests (tools/list, tools/call) — hooks into new or cached session. | | GET /mcp | Streams Server-Sent Events (SSE) for continuous clients. | | DELETE /mcp | Gracefully terminate an active server. |

Tool Reference

Currently bundling 48 Native Tools mapped through specific modules.

📁 Filesystem

(All paths resolved relative to FS_ROOT protecting against directory traversal)

• read_file, write_file, list_dir, make_dir, delete_path, copy_path, move_path, search_files, file_info

🌿 Git

(Powered by simple-git, targets directories relative to FS_ROOT)

• git_status, git_diff, git_log, git_branch, git_add, git_commit, git_push, git_pull, git_clone, git_stash, git_show

🌐 Network

• http_request, ping, dns_lookup, port_scan, whois, traceroute, download_file, check_connectivity

💻 Shell

(Managed by the injected ProcessManager service isolating spawn logs in memory)

• run_command, spawn_process, list_processes, get_process_logs, kill_process, system_info, get_env, which, ps

🖥️ System

• cron_list, disk_usage, open, notify, clipboard_write, clipboard_read, screenshot, list_installed

🐘 Postgres

(Connects dynamically on-the-fly rather than hardcoded global connections)

• pg_query: Execute parameterized raw SQL queries directly.
• pg_list_tables: Enumerate all active tables ignoring system schemas.
• pg_describe_table: Interrogate type formats, nullability, and default requirements for a target schema table.

Note: The Postgres tools require you to provide a connectionString argument directly through the LLM interface, keeping your server completely credential-less by design.

Environment Variables

Handled seamlessly using dotenv.

| Variable | Required | Default | Description | |---|---|---|---| | PORT | No | 3000 | HTTP port the Express server binds to. | | FS_ROOT | No | /host-home | Root directory for File operations. Path constraints enforce this border. | | MCP_AUTH_TOKEN | Yes (prod) | (none) | Bearer auth token for X-MCP-Token. Omitting heavily warns during dev mode. | | NODE_ENV | No | development | Setting to production enforces Token Auth checks. |

Extending with New Tools

Adding tools is significantly easier with the Modular Architecture:

1. Create a strictly-typed configuration inside your target domain layer (e.g. src/tools/custom/myTool.ts):

import { z } from "zod";
import type { ToolDefinition } from "../../types/index.js";
import { ok } from "../../utils/response.js";

export const myCustomTool: ToolDefinition = {
  name: "custom_tool",
  description: "Does something specific",
  schema: {
    target: z.string().describe("What to target"),
  },
  handler: async ({ target }) => {
    return ok(`Executed logic on ${target}`);
  }
};

2. Import and append your tool array to registerAllTools in src/tools/registry.ts.

Security Model

| Concern | Mitigation | |---|---| | Path traversal | safePath() heavily anchors against FS_ROOT bounds. | | Secret leakage | get_env redacts items masking standard keys (secrets/passwords/apis). | | Docker Isolation | Runs natively as unescalated mcpuser relying on safe Mount Points. | | DB Access | Handled dynamically avoiding persistent env leaks in logs. |