# FDTD Lumerical MCP

Local MCP server for controlling Ansys Lumerical FDTD from Codex.

The server uses the Lumerical Python Automation API (`lumapi`) from an existing
Ansys/Lumerical installation. `lumapi` is not installed from pip.

## Setup

```powershell
cd "C:\path\to\FDTD-Lumerical-mcp"
python -m pip install -e ".[dev]"
```

Set `LUMERICAL_API_PATH` if automatic discovery cannot find `lumapi.py`:

```powershell
$env:LUMERICAL_API_PATH = "C:\Program Files\Ansys Inc\vXXX\Lumerical\api\python\lumapi.py"
```

Optional workspace override:

```powershell
$env:FDTD_WORKSPACE = "C:\path\to\FDTD-Lumerical-mcp\workspace"
```

Run the server:

```powershell
python -m fdtd_mcp.server
```

## Verification

Run unit tests without opening FDTD:

```powershell
python -m pytest -q
```

Run the real MCP/FDTD smoke test:

```powershell
$env:FDTD_INTEGRATION = "1"
python -m pytest -q -m integration
```

## Codex MCP Config

See `.codex/config.toml.example`.

## Safety Model

Project and export file paths are restricted to `FDTD_WORKSPACE`, which defaults
to the repository `workspace/` directory when the MCP server is launched from
the project root.

Tools that execute user script or run simulations should stay in prompt approval
mode in Codex configuration.