# ThinkPLC-MCP
**ThinkPLC-MCP** is a server designed to interface with **SIEMENS PLC S7-1500/1200** using their **JSON-RPC 2.0 API**. It exposes API functionalities as **MCP tools**, enabling AI assistants and other MCP-compatible clients to interact with the PLC programmatically.
---
## 🔧 Features
- Connects to a **SIEMENS PLC API (Webserver)** endpoint
- Provides MCP tools for:
- ✅ User authentication (`login`, `logout`, `ChangePassword-user`)
- ✅ Check PLC connectivity (`ping`)
- ✅ Retrieve user permissions via `Api-GetPermissions` after login
- ✅ Get API version with `Api-Version`
- ✅ List available API methods using `Api-Browse`
- ✅ Retrieve structure information with `Api-GetQuantityStructures`
- ✅ Get password security policies with `Api-GetPasswordPolicy`
- ✅ Browse tags and metadata using `PlcProgram-Browse`
- ✅ Read single variables via `PlcProgram-Read`
- ✅ Write Boolean, Number, or String tags with `PlcProgram-Write-*`
- ✅ Read the current CPU operating mode with `Plc-ReadOperatingMode`
- ✅ Request a change of operating mode using `Plc-RequestChangeOperatingMode`
- ✅ Read the CPU system time (`Plc-ReadSystemTime`)
- ✅ Set the CPU system time (`Plc-SetSystemTime`)
- ✅ Read available project languages (`Project-ReadLanguages`)
- ✅ Browse active alarms (`Alarms-Browse`)
- ✅ Acknowledge alarms (`Alarms-Acknowledge`)
- ✅ Browse diagnostic buffer entries (`DiagnosticBuffer-Browse`)
- 🔄 Optional: automatic service account login with token refresh
---
## ⚙️ Prerequisites
- [Node.js](https://nodejs.org/) (v18.x or later recommended)
- npm (comes bundled with Node.js)
- Access to a running **SIEMENS PLC API (Webserver)**
---
## ⚙️ Configuration
This server uses a `config.js` file written in **ES Module** syntax.
### Example `config.js`:
```js
export const config = {
URL: "https://<PLC-IP-Address>/api/jsonrpc", // required
userName: "your-username", // optional
pwr: "your-password", // optional
};
```
## 🚀 Getting Started
1. Navigate to the project folder:
```bash
cd your-project-directory
```
2. Install dependencies:
```bash
npm install
```
3. Edit config.js as shown above.
4. Start the server
```bash
node start
```
### 🖥️ Connecting with Claude Desktop
To use this MCP server with Claude AI (desktop version):
1. Find or create the claude_desktop_config.json file
(typically in the Claude app config folder).
2. Add or update the following:
```json
{
"mcpServers": {
"ThinkPLC-MCP": {
"command": "npx",
"args": ["mcp-remote", "http://localhost:5000/mcp"]
}
}
}
```
4. Ensure @modelcontextprotocol/tools is installed:
```bash
npm install -g @modelcontextprotocol/tools
```
