Model Context Protocol server for CODESYS automation platform
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.
Project Management
open_project)create_project)save_project)POU Management
create_pou)set_pou_code)create_property)create_method)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.(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.)
The recommended way to install is globally using npm:
npm install -g @codesys/mcp-toolkit
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).
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).
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):
{
"mcpServers": {
// ... other servers ...
"codesys_local": {
"command": "codesys-mcp-tool", // <<< Use the direct command name
"args": [
// Pass arguments directly to the tool using flags
"--codesys-path", "C:\Program Files\Path\To\Your\CODESYS\Common\CODESYS.exe",
"--codesys-profile", "Your CODESYS Profile Name"
// Optional: Add --workspace "/path/to/your/projects" if needed
]
}
// ... other servers ...
}
}
Key Steps:
"C:\Program Files\Path\To\Your\CODESYS\Common\CODESYS.exe" with the full, correct path to your specific CODESYS.exe file."Your CODESYS Profile Name" with the exact name of the CODESYS profile you want to use (visible in the CODESYS UI).codesys-mcp-tool command is accessible in the system PATH where the MCP Client application runs. Global installation via npm install -g usually handles this.npx - Not Recommended)Launching with npx has been observed to cause immediate errors ('C:\Program' is not recognized...) in some environments, likely due to how npx handles the execution environment. Use the Direct Command method above if possible. If you must use npx:
// Example using npx (POTENTIALLY PROBLEMATIC - USE WITH CAUTION):
{
"mcpServers": {
"codesys_local": {
"command": "npx",
"args": [
"-y", // Tells npx to install temporarily if not found globally
"@codesys/mcp-toolkit",
// Arguments for the tool MUST come AFTER the package name
"--codesys-path", "C:\Program Files\Path\To\Your\CODESYS\Common\CODESYS.exe",
"--codesys-profile", "Your CODESYS Profile Name"
]
}
}
}
(Note: The -- separator after the package name might sometimes help npx but is not guaranteed to fix the environment issue.)
When running codesys-mcp-tool directly or configuring it, you can use these arguments:
-p, --codesys-path <path>: Full path to CODESYS.exe. (Required, overrides CODESYS_PATH env var, has a default but relying on it is not recommended).-f, --codesys-profile <profile>: Name of the CODESYS profile. (Required, overrides CODESYS_PROFILE env var, has a default but relying on it is not recommended).-w, --workspace <dir>: 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.-h, --help: Show help message.--version: Show package version.'C:\Program' is not recognized... error immediately after connection:
npx within an environment like Claude Desktop. The execution environment (PATH variable) provided to the process likely causes an internal CODESYS command (like running Python) to fail."command": "codesys-mcp-tool") instead of using "command": "npx". See the Recommended Configuration Method section above.Tool Fails / Errors in Output:
INTEROP: messages or Python DEBUG: / ERROR: messages printed to stderr from the CODESYS script execution.--codesys-path and --codesys-profile arguments passed to the command are correct and point to a valid CODESYS installation with scripting enabled./).command not found: codesys-mcp-tool:
npm install -g @codesys/mcp-toolkit).PATH environment variable. Find it with npm config get prefix and add the bin subdirectory (or the main directory itself on Windows) to your PATH.Check Logs:
C:\Users\<YourUsername>\AppData\Roaming\Claude\logs (Windows)Contributions, issues, and feature requests are welcome! Feel free to check the issues page. (Optionally add a CONTRIBUTING.md file with more details).
This project is licensed under the MIT License - see the LICENSE file for details.
