Components of the Einstein Toolkit include:

Cactus Framework

The Cactus Framework and Computational Toolkit provides an parallel, collaborative, component framework for the Einstein Toolkit. Cactus was developed by the numerical relativity community but now supports scientific applications in different disciplines. The Cactus Computational Toolkit is a set of thorns that provide general capabilities used by the Einstein Toolkit such as I/O, coordinates and boundary conditions. Distribution: The Cactus Framework is distributed under an open source license from the Cactus website

Component Lists and GetComponents

The Einstein Toolkit component list contains the locations of the source code and associated tools for simulations, including Cactus thorns. The component list is written using the Component Retrieval Language and can be checked out using the GetComponents tools.

Simulation Factory

The simulation factory includes configuration and batch script files for compiling and running simulations using the Cactus code on many different architectures. Additional capabilities provide for management of simulations, simplifying checkpoint & restart, and remote use of machines. The Einstein Consortium have selected the simulation factory as the default mechanism for supporting the easy use of Cactus on heterogeneous resources. Distribution: Bitbucket git repository:

Cactus Thorns

Code for the centrally supported Cactus thorns in the Einstein Toolkit. Additional thorns are maintained in external repositories with open access. Distribution: Bitbucket: Cactuscode and Einstein Toolkit. Some components are also living in the Einstein Toolkit SVN repository, an overview of which is here, but includes also components that now moved to Bitbucket:

Parameter Files

Example Cactus code parameter files for Einstein Toolkit beginners. Simple examples are provided for a Kerr-Schild black hole, a binary black hole coalescence, and a static TOV star. Distribution: CactusCode and EinsteinToolkit.

SelfForce-1D code.

SelfForce-1D is a code infrastructure for simulating Extreme Mass Ratio Inspirals using the effective source approach to the self-force problem. Currently, only a scalar charge in a Schwarzschild spacetime background has been implemented, but it is the hope that more systems will be added soon.


kuibit is a Python library to post-process simulations performed with Cactus. The goal of the package is to enable users to pursue their scientific goals without having to worry about technical or low-level details. kuibit is designed to be user and developer friendly and has comprehensive documentation.