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AutoCAD LT AutoLISP MCP Server

Enables natural language control of AutoCAD LT by generating and executing AutoLISP code to create drawings and P&ID diagrams.

Installation

Add the following to your MCP client configuration file.

Configuration

View docs

{
  "mcpServers": {
    "puran-water-autocad-mcp": {
      "command": "path\\\\to\\\\autocad-mcp\\\\venv\\\\Scripts\\\\python.exe",
      "args": [
        "path\\\\to\\\\autocad-mcp\\\\server_lisp_fast.py"
      ]
    }
  }
}

You can control AutoCAD LT 2024 and newer through natural language by generating and executing AutoLISP code via this MCP server. It connects your MCP client or Claude Desktop to AutoCAD LT to create engineering drawings, P&ID diagrams, and technical documentation through conversational prompts.

How to use

You will run the MCP server locally and connect it to your MCP client. Use conversational prompts to describe the drawing actions you want, and the server translates them into AutoLISP commands that AutoCAD LT executes. If you have the CTO Library, you gain full P&ID symbol support and intelligent attribute handling; otherwise, you can still perform basic drawing operations and block management.

How to install

Prerequisites include a supported AutoCAD LT installation and Python on your system.

Additional setup steps

1. Install dependencies 2. Configure your MCP client with the appropriate server configuration 3. Start the server and test the connection

Setup and run details

Install dependencies by cloning the repository, creating a virtual environment, and installing Python requirements. Then configure your MCP client to use one of the local server options and start the server accordingly. If you have the CTO Library, enable the fast server path for better performance.

Troubleshooting and notes

If loading errors occur, ensure the AutoLISP paths are trusted in AutoCAD LT. If P&ID tools fail, verify the CTO Library path or opt to use the standard server for basic drawing operations. Run the test connection script to verify the integration works.

What's new in this version

This MCP server adds full CTO Library integration for P&ID symbols, intelligent block attributes for equipment schedules, a fast mode server with significant performance improvements, batch operations, and dedicated P&ID process tools.

Security and usage notes

Operate the server in a trusted environment. Run AutoCAD LT with proper permissions and ensure that generated AutoLISP code is from trusted prompts. Do not expose the MCP server to untrusted networks without appropriate safeguards.

Available tools

create_line

Draw a straight line between two points in AutoCAD LT.

create_circle

Create a circle given a center point and radius.

create_text

Place text with optional rotation for labels and annotations.

create_polyline

Generate a polyline from a series of points.

create_rectangle

Draw a rectangle using corner points.

insert_block

Insert a block with optional attributes and positioning.

set_layer_properties

Create or modify layers with a full set of properties.

move_last_entity

Move the most recently created entities to a new location.

update_block_attribute

Modify attributes within an inserted block.

create_arc

Create an arc by center, radius, and angles.

create_ellipse

Draw an ellipse defined by major axis and ratio.

create_hatch

Apply hatch patterns to closed areas.

create_mtext

Add multiline formatted text blocks.

create_linear_dimension

Add linear dimensions to drawings.

list_pid_symbols

List available P&ID symbols from the CTO Library.

insert_pid_symbol

Insert a symbol from the CTO P&ID library (CTO-required).

insert_pid_equipment_with_attribs

Insert equipment blocks with proper CTO attributes.

insert_valve_with_attributes

Place valves with the correct CTO attributes.

insert_equipment_tag

Add equipment identification tags to blocks.

insert_equipment_description

Attach descriptive blocks to equipment.

insert_line_number_tag

Annotate lines with their process line numbers.

draw_process_line

Draw piping between equipment points.

connect_equipment

Connect equipment with orthogonal piping routing.

add_flow_arrow

Add directional flow indicators on process lines.