tidy3d 2.10.2

A fast FDTD solver

Tidy3D

Tidy3D is a software package for solving extremely large electrodynamics problems using the finite-difference time-domain (FDTD) method. It can be controlled through either an open source python package or a web-based graphical user interface.

This repository contains the python API to allow you to:

• Programmatically define FDTD simulations.
• Submit and manage simulations running on Flexcompute's servers.
• Download and postprocess the results from the simulations.

Installation

Signing up for tidy3d

Note that while this front end package is open source, to run simulations on Flexcompute servers requires an account with credits. You can sign up for an account here. After that, you can install the front end with the instructions below, or visit this page in our documentation for more details.

Quickstart Installation

To install the Tidy3D Python API locally, the following instructions should work for most users.

pip install --user tidy3d
tidy3d configure --apikey=XXX

Where XXX is your API key, which can be copied from your account page in the web interface.

In a hosted jupyter notebook environment (eg google colab), it may be more convenient to install and configure via the following lines at the top of the notebook.

!pip install tidy3d
import tidy3d.web as web
web.configure("XXX")

Advanced installation instructions for all platforms is available in the documentation installation guides.

Authentication Verification

To test the authentication, you may try importing the web interface via.

python -c "import tidy3d; tidy3d.web.test()"

It should pass without any errors if the API key is set up correctly.

To get started, our documentation has a lot of examples for inspiration.

Common Documentation References

API Resource	URL
Installation Guide	https://docs.flexcompute.com/projects/tidy3d/en/latest/install.html
Documentation	https://docs.flexcompute.com/projects/tidy3d/en/latest/index.html
Example Library	https://docs.flexcompute.com/projects/tidy3d/en/latest/notebooks/docs/index.html
FAQ	https://docs.flexcompute.com/projects/tidy3d/en/latest/faq/docs/index.html

FlexAgent MCP

FlexAgent adds an AI-assisted layer on top of Tidy3D via the Model Context Protocol (MCP); read more about AI-assisted simulation in Tidy3D. Install the tidy3d-mcp server when you want that experience inside an MCP client without the Tidy3D extension for Visual Studio Code and Cursor.

These commands assume uv is installed on your machine.

Register the server with your MCP client - use the block below that matches your CLI.

Codex CLI / IDE

codex mcp add tidy3d -- uvx tidy3d-mcp --api-key "YOUR_TIDY3D_API_KEY"

Claude CLI / Desktop / Code

claude mcp add tidy3d -- uvx tidy3d-mcp --api-key "YOUR_TIDY3D_API_KEY"

Gemini CLI

Create or edit .gemini/settings.json (project) or ~/.gemini/settings.json (global):

{
  "mcpServers": {
    "tidy3d": {
      "command": "uvx",
      "args": ["tidy3d-mcp", "--api-key", "YOUR_TIDY3D_API_KEY"]
    }
  }
}

Cursor CLI / IDE

Cursor reuses the same schema across the editor and cursor-agent. Configure .cursor/mcp.json (per-project) or ~/.cursor/mcp.json (global) and then run cursor-agent mcp list to verify:

{
  "mcpServers": {
    "tidy3d": {
      "command": "uvx",
      "args": ["tidy3d-mcp", "--api-key", "YOUR_TIDY3D_API_KEY"]
    }
  }
}

Related Source Repositories

Name	Repository
Source Code	https://github.com/flexcompute/tidy3d
Notebooks Source	https://github.com/flexcompute/tidy3d-notebooks
FAQ Source Code	https://github.com/flexcompute/tidy3d-faq

Issues / Feedback / Bug Reporting

Your feedback helps us immensely!

If you find bugs, file an Issue. For more general discussions, questions, comments, anything else, open a topic in the Discussions Tab.

License

GNU LGPL