FDTD Lumerical

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

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

Set LUMERICAL_API_PATH if automatic discovery cannot find lumapi.py:

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

Optional workspace override:

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

Run the server:

python -m fdtd_mcp.server

Verification

Run unit tests without opening FDTD:

python -m pytest -q

Run the real MCP/FDTD smoke test:

$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.