species is compatible with Python versions 3.7/3.8/3.9 and is available in the PyPI repository and on Github.

Installation from PyPI


Before installing species, it is required to separately install cython:

$ pip install cython

The species toolkit can be installed with the pip package manager:

$ pip install species

Or, to update to the most recent version:

$ pip install --upgrade species

Please check for any errors and warnings during the installation to make sure that all dependencies are correctly installed.


The PyMultiNest package requires the manual installation of MultiNest. Please follow the instructions for the building the library and make sure that the LD_LIBRARY_PATH (on Linux) or DYLD_LIBRARY_PATH (on macOS) environment variable is set. It is also possible to use species without installing MultiNest (but a warning will appear), apart from the functionalities that rely on PyMultiNest.

Installation from Github

Using pip

The version on Github contains the latest implementations and can also be installed with pip:

$ pip install git+git://


In case an error occurs during installation then possibly pip needs to be updated to the latest version:

$ pip install --upgrade pip

Cloning the repository

Alternatively, in case you want to look into the code, it is best to clone the repository:

$ git clone

Then, the package is installed by running pip in the local repository folder:

$ pip install -e .

New commits can be pulled from Github once a local copy of the repository exists:

$ git pull origin main

Do you want to make changes to the code? Please fork the species repository on the Github page and clone your own fork instead of the main repository. Contributions and pull requests are welcome (see Contributing section).

Testing species

The installation can now be tested, for example by starting Python in interactive mode and printing the version number of the installed package:

>>> import species
>>> species.__version__