johannesPettersson80/codesys-mcp-toolkit

A Model Context Protocol (MCP) server for CODESYS V3 programming environments. This toolkit enables seamless interaction between MCP clients (like Claude Desktop) and CODESYS, allowing automation of project management, POU creation, code editing, and compilation tasks via the CODESYS Scripting Engine.
🌟 Features
- **Project Management**
- Open existing CODESYS projects (open_project)
- Create new projects from standard templates (create_project)
- Save project changes (save_project)
- **POU Management**
- Create Programs, Function Blocks, and Functions (create_pou)
- Set declaration and implementation code (set_pou_code)
- Create properties for Function Blocks (create_property)
- Create methods for Function Blocks (create_method)
- Compile projects (compile_project)
- **MCP Resources**
- codesys://project/status: Check scripting status and currently open project state.
- codesys://project/{+project_path}/structure: Retrieve the object structure of a specified project.
- codesys://project/{+project_path}/pou/{+pou_path}/code: Read the declaration and implementation code for a specified POU, Method, or Property accessor.
📋 Prerequisites
- **CODESYS V3**: A working CODESYS V3 installation (tested with 3.5 SP21) with the **Scripting Engine** component enabled during installation.
- **Node.js**: Version 18.0.0 or later is recommended.
- **MCP Client**: An MCP-enabled application (e.g., Claude Desktop).
*(Note: CODESYS uses Python 2.7 internally for its scripting engine, but this toolkit handles the interaction; you do not need to manage Python separately.)*
🚀 Installation
The recommended way to install is globally using npm:
This installs the package globally, making the codesys-mcp-tool command available in your system's terminal PATH.
*(Advanced users can also install from source for development - see CONTRIBUTING.md if available).*
🔧 Configuration (IMPORTANT!)
This toolkit needs to know where your CODESYS installation is and which profile to use. Configuration is typically done within your MCP Client application (like Claude Desktop).
Recommended Configuration Method (Direct Command)
Due to potential environment variable issues (especially with PATH) when launching Node.js tools via wrappers like npx within certain host applications (e.g., Claude Desktop), it is **strongly recommended** to configure your MCP client to run the installed command codesys-mcp-tool **directly**.
**Example for Claude Desktop (settings.json -> mcpServers):**
json
{
"mcpServers": {
// ... other servers ...
"codesys_local": {
"command": "codesys-mcp-tool", // : Full path to CODESYS.exe. (Required, overrides CODESYS_PATH env var, has a default but relying on it is not recommended).
* -f, --codesys-profile : Name of the CODESYS profile. (Required, overrides CODESYS_PROFILE env var, has a default but relying on it is not recommended).
* -w, --workspace : Workspace directory for resolving relative project paths passed to tools. Defaults to the directory where the command was launched (which might be unpredictable when run by another application). Setting this explicitly might be needed if using relative paths.