MCP Demo Server

A collection of Model Context Protocol (MCP) server implementations for databases, files, HTTP APIs, and message middleware.

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Overview

This repository provides MCP servers you can plug into Cursor or any MCP-compatible client:

• server.js - Basic hello-world MCP server
• server-mysql.js - MySQL query and CRUD-like operations
• server-tdengine.js - TDengine SQL query and data operations via REST
• server-mongodb.js - MongoDB query/insert/update/delete/list collections
• server-read-files.js - File reading tool
• server-axios.js - HTTP GET/POST/PUT/DELETE tools
• server-mqtt.js - MQTT subscribe/publish with runtime topic management
• server-kafka.js - Kafka consume/publish with runtime subscriptions

Requirements

• Node.js 18+
• npm

Installation

npm install
cp .env.example .env

Use a different env file when needed:

set ENV_FILE=.env.beta && node server-mysql.js

Environment Configuration

All database servers load config via dotenv:

• Default: load .env in the project root
• Override: set ENV_FILE to another file path
• Template: see .env.example

The project supports optional SSH jump tunnels for MySQL, MongoDB, and TDengine using:

• SSH_JUMPS (global jumps)
• MYSQL_SSH_JUMPS, MONGO_SSH_JUMPS, TDENGINE_SSH_JUMPS (service-specific jumps)

Tool Matrix

server.js

• say_hello

server-mysql.js (mysql-tools)

• query_mysql
• insert_mysql
• update_mysql
• delete_mysql

server-tdengine.js (tdengine-tools)

• query_tdengine
• insert_tdengine
• update_tdengine
• delete_tdengine

server-mongodb.js (mongo_db-tools)

• query_mongo
• mongo_insert
• mongo_update
• mongo_delete
• list_mongo_collections

server-read-files.js (file-tools)

• readFile

server-axios.js (axios-tools)

• call_api_get
• call_api_post
• call_api_put
• call_api_delete

server-mqtt.js (mqtt-tools)

• mqtt_status
• mqtt_get_messages
• mqtt_publish
• mqtt_subscribe
• mqtt_subscribe_batch
• mqtt_unsubscribe
• mqtt_clear_messages

server-kafka.js (kafka-tools)

• kafka_status
• kafka_publish
• kafka_subscribe
• kafka_get_messages
• kafka_clear_messages

Run Servers

node server.js
node server-mysql.js
node server-tdengine.js
node server-mongodb.js
node server-read-files.js
node server-axios.js
node server-mqtt.js --host alpha --topics "/events/#"
node server-kafka.js --brokers localhost:9092 --topics demo-topic

Cursor MCP Config Example

{
  "mcpServers": {
    "mysql-tools": {
      "command": "node",
      "args": ["D:/projects/mcp-demo-server/server-mysql.js"],
      "env": { "ENV_FILE": "D:/projects/mcp-demo-server/.env" }
    },
    "tdengine-tools": {
      "command": "node",
      "args": ["D:/projects/mcp-demo-server/server-tdengine.js"],
      "env": { "ENV_FILE": "D:/projects/mcp-demo-server/.env" }
    },
    "mongo-db-tools": {
      "command": "node",
      "args": ["D:/projects/mcp-demo-server/server-mongodb.js"],
      "env": { "ENV_FILE": "D:/projects/mcp-demo-server/.env" }
    }
  }
}

Main Dependencies

• @modelcontextprotocol/sdk
• axios
• dotenv
• kafkajs
• mongodb
• mqtt
• mysql2
• tunnel-ssh
• zod

Security Notes

Before production use:

1. Replace default credentials and rotate secrets.
2. Restrict database privileges for MCP accounts.
3. Limit operation flags in .env (for example disable delete).
4. Restrict filesystem access scope.
5. Enable stronger TLS/certificate verification where applicable.

License

Provided as-is for demonstration and learning purposes.