Content
# Civil 3D MCP Server
An MCP (Model Context Protocol) server that enables AI assistants (Claude, Cline, etc.) to interact with Autodesk Civil 3D through natural language.
## Architecture
```
┌─────────────────┐ stdio ┌──────────────────┐ TCP/JSON-RPC ┌──────────────────┐
│ AI Assistant │ ◄────────────► │ MCP Server (TS) │ ◄──────────────────► │ Civil 3D Plugin │
│ (Claude, Cline) │ │ Node.js │ port 8080 │ (.NET 8.0 C#) │
└─────────────────┘ └──────────────────┘ └──────────────────┘
│
Civil 3D API
(Surfaces, Alignments,
Points, Corridors...)
```
The system has two components:
1. **MCP Server** (TypeScript/Node.js) — Communicates with AI assistants via MCP protocol
2. **Civil 3D Plugin** (C# .NET 8.0) — Runs inside Civil 3D and executes API commands
## Available Tools
| Tool | Actions | Description |
|------|---------|-------------|
| `civil3d_health` | health | Check plugin connectivity |
| `civil3d_drawing` | info, settings, save, undo, redo, list_object_types, get_selected | Drawing operations |
| `civil3d_surface` | list, get, get_elevation, get_statistics, create, delete, add_points, add_breakline, add_boundary, extract_contours, compute_volume | Surface management |
| `civil3d_alignment` | list, get, create, delete, station_to_point, point_to_station | Alignment operations |
| `civil3d_profile` | list, get, get_elevation, create_from_surface, create_layout, delete | Profile management |
| `civil3d_corridor` | list, get, rebuild, get_surfaces, get_feature_lines, compute_volumes | Corridor operations |
| `civil3d_pipe` | list_networks, get_network, get_pipe, get_structure, create_network, add_pipe, add_structure, check_interference | Pipe networks |
| `civil3d_point` | list, get, create, delete, list_groups, import | COGO points |
| `civil3d_geometry` | create_line, create_polyline, create_3d_polyline, create_text, create_mtext | Basic AutoCAD geometry |
## Setup
### 1. Build the MCP Server
```bash
npm install
npm run build
```
### 2. Build the Civil 3D Plugin
1. Copy the required DLLs from your Civil 3D installation to `C_References/` (see [C_References/README.md](C_References/README.md))
2. Build the plugin:
```bash
cd plugin/Civil3dMcpPlugin
dotnet build
```
### 3. Load the Plugin in Civil 3D
1. Open Civil 3D 2025+
2. Type `NETLOAD` in the command line
3. Browse to `plugin/Civil3dMcpPlugin/bin/Debug/net8.0-windows/Civil3dMcpPlugin.dll`
4. The plugin starts automatically. Use `C3DMCPSTATUS` to verify.
### 4. Configure Your AI Assistant
**Claude Desktop** — Add to `claude_desktop_config.json`:
```json
{
"mcpServers": {
"civil3d": {
"command": "node",
"args": ["/path/to/civil3d-mcp/build/index.js"]
}
}
}
```
## Environment Variables
| Variable | Default | Description |
|----------|---------|-------------|
| `CIVIL3D_HOST` | `localhost` | Civil 3D plugin host |
| `CIVIL3D_PORT` | `8080` | Civil 3D plugin port |
| `CIVIL3D_CONNECT_TIMEOUT` | `5000` | Connection timeout (ms) |
| `CIVIL3D_COMMAND_TIMEOUT` | `120000` | Command execution timeout (ms) |
| `LOG_LEVEL` | `info` | Log level (debug, info, warn, error) |
## Plugin Commands
| Command | Description |
|---------|-------------|
| `C3DMCPSTART` | Start the TCP listener |
| `C3DMCPSTOP` | Stop the TCP listener |
| `C3DMCPSTATUS` | Check listener status |
## License
MIT
