Getting started#

PyAdditive is a Python client library for the Ansys Additive server. The Ansys Additive server is distributed with the Additive option of the Structures package in the Ansys unified installation.


PyAdditive requires Ansys 2024 R1 or later.


The simulations described in this documentation require an Additive Suite license. To obtain a license, contact your Ansys sales representative or see

Starting a session#

There are multiple ways to start a session with the PyAdditive client.

Starting a local session#

Instantiating an Additive object starts the local installation of the Additive server.

import ansys.additive.core as pyadditive
additive = pyadditive.Additive()

Starting a remote session#

You can start a remote session by specifying the host name and port of the server.

import ansys.additive.core as pyadditive
additive = pyadditive.Additive(host="", port=12345)

Alternative startup methods#

For additional session startup methods, see the documentation for the Additive class.

Run simulations#

For examples of the types of simulations possible with PyAdditive, see Examples.


Package dependencies#

PyAdditive is supported on Python version 3.9 and later. Previous versions of Python are no longer supported as outlined in this Moving to require Python 3 statement.

PyAdditive dependencies are automatically checked when packages are installed. Included in these dependencies are these projects:

  • ansys-api-additive: Python package containing the auto-generated

    gRPC Python interface files for the Additive service

  • NumPy: Fundamental package for scientific computing with Python, providing

    data array access for PyAdditive

  • PyVista: 3D visualization library for interactive 3D plotting of PyAdditive results.

  • Panel: Web app framework used for interactive visualization of PyAdditive results.

Install the package#

PyAdditive has three installation modes: user, developer, and offline.

Install in user mode#

Install Python if it is not already installed.

Before installing PyAdditive in user mode, run this command to make sure that you have the latest version of pip:

python -m pip install -U pip

Then, run this command to install PyAdditive:

python -m pip install ansys-additive-core

Install in developer mode#

Installing PyAdditive in developer mode allows you to modify the source code and enhance it.


Before contributing to PyAdditive, see the Contributing topic in the PyAnsys Developer’s Guide. You should be thoroughly familiar with this guide.

To install PyAdditive in developer mode, perform these steps:

  1. Clone the repository and access the directory where it has been cloned:

    git clone
    cd pyadditive
  2. Create a clean Python virtual environment and activate it:

    # Create a virtual environment
    python -m venv .venv
    # Activate it in a POSIX system
    source .venv/bin/activate
    # Activate it in Windows CMD shell
    # Activate it in Windows Powershell

    If you require additional information on virtual environments, see Creation of virtual environments in the Python documentation.

  3. Install the required build system tools:

    python -m pip install -U pip tox
  4. Verify your development installation:

    tox -e py
  5. Optionally, install the project in editable mode:

    python -m pip install -e .
  6. When finished, you can exit the virtual environment:


Install in offline mode#

If you lack an internet connection on your installation machine (or you do not have access to the private Ansys PyPI packages repository), you should install PyAdditive by downloading the wheelhouse archive from the Releases page for your corresponding machine architecture.

Each wheelhouse archive contains all the Python wheels necessary to install PyAdditive from scratch on Windows, Linux, and MacOS from Python 3.9 to 3.12. You can unzip and install the wheelhouse archive on an isolated system with a fresh Python installation or in a virtual environment.

For example, on Linux with Python 3.9, unzip then install the wheelhouse archive with these commands:

unzip wheelhouse
pip install ansys-additive-core -f wheelhouse --no-index --upgrade --ignore-installed

If you’re on Windows with Python 3.9, unzip the wheelhouse archive to a wheelhouse directory and then install using the preceding pip command.

Consider using a virtual environment for the installation.


This project takes advantage of tox. This tool automates common development tasks (similar to Makefile), but it is oriented towards Python development.

Using tox#

While Makefile has rules, tox has environments. In fact, tox creates its own virtual environment so that anything being tested is isolated from the project to guarantee the project’s integrity.

The following commands are provided:

  • tox -e style: Checks for coding style quality.

  • tox -e py: Checks for and runs unit tests.

  • tox -e py-coverage: Checks for and runs unit tests, generating code coverage reports.

  • tox -e doc: Checks for building the documentation successfully.

Raw testing#

If required, from the command line, you can call style commands like black, isort, and flake8 and call unit testing commands like pytest. However, this does not guarantee that your project is being tested in an isolated environment, which is the reason why tools like tox exist.

To run unit tests without using tox, first install the pytest-cov package in editable mode:

python -m pip install pytest-cov

python -m pip install -e .

Then, run this command from the root folder of the project:

python -m pytest

System testing on localhost#

System testing can be done on localhost using the startup method described in Starting a local session within a Python script or Jupyter notebook. The examples folder of the PyAdditive repository contains script files that can be used for testing or converted to Jupyter notebooks using Jupytext.

To test with a notebook, you need to install and run JupyterLab:

python -m venv jupyter_venv​


pip install jupyterlab​

pip install jupyterlab

jupyter lab

The URL for opening JupyterLab in your browser is http://localhost:8888/lab. Note that the port number may be different, but the port number is listed in the JupyterLab startup messages.

A note on pre-commit#

The style checks take advantage of pre-commit. Developers are not forced but encouraged to install this tool by running this command:

python -m pip install pre-commit && pre-commit install


For building documentation, you can run the usual rules provided in the Sphinx Makefile, such as:

make -C doc/ html && your_browser_name doc/html/index.html

However, the recommended way of checking documentation integrity is to use tox:

tox -e doc && your_browser_name .tox/doc_out/index.html


If you would like to create either source or wheel files, start by installing the building requirements and then executing the build module:

python -m pip install -U pip build twine
python -m build
python -m twine check dist/*