4 Installation

In this section we discuss how to install and setup the MOSEK Fusion API for Python.


Before running this MOSEK interface please make sure that you:

  • Installed MOSEK correctly. Some operating systems require extra steps. See the Installation guide for instructions and common troubleshooting tips.

  • Set up a license. See the Licensing guide for instructions.


The Fusion API for Python requires Python 3 with NumPy. The supported versions of Python are shown below:

Table 4.1 Supported Python versions.



Linux 64 bit x86


Linux 64 bit ARM


macOS 64 bit x86


macOS 64 bit ARM


Windows 64 bit x86


4.1 Anaconda

The MOSEK Optimization Suite can be installed as an Anaconda package, see https://anaconda.org/MOSEK/mosek, for example by running

conda install -c mosek mosek

If you installed the MOSEK package as part of Anaconda, no additional setup is required.

4.2 PIP and Wheels

The MOSEK Optimization Suite can be installed as a Wheels package with PIP, using

pip install Mosek --user

(skip --user for a system-wide installation).

If you installed the MOSEK package with PIP, no additional setup is required.

4.3 Manual installation

Locating files in the MOSEK Optimization Suite

The relevant files of the Fusion API for Python are organized as reported in Table 4.2.

Table 4.2 Relevant files for the Fusion API for Python.

Relative Path




Python 3 install






Additional data



  • <MSKHOME> is the folder in which the MOSEK Optimization Suite has been installed,

  • <PLATFORM> is the actual platform among those supported by MOSEK, i.e. win64x86, linux64x86 or osx64x86.

Manual install and setting up paths

To install MOSEK for Python run the <PYTHON3DIR>/setup.py script. This will add the MOSEK module to your Python distribution’s library of modules. The script accepts the standard options typical for Python setup scripts. For instance, to install MOSEK in the user’s local library run:

$ python <PYTHON3DIR>/setup.py install --user

on Linux and macOS or

C:\> python <PYTHON3DIR>\setup.py install --user

on Windows.

For a system-wide installation drop the --user flag.

4.4 Testing the Installation

First of all, to check that the Fusion API for Python was properly installed, start Python and try

import mosek

The installation can further be tested by running some of the enclosed examples. Open a terminal, change folder to <EXDIR> and use Python to run a selected example, for instance:

python lo1.py

4.5 Troubleshooting

error: could not create ‘build’: Access is denied

If an attempt to install the Python interface results in an error such as

error: could not create 'build': Access is denied

then you have no write permissions to the folder where MOSEK is installed. This can happen for example if the package was installed by an administrator, and a user is trying to set up the Python interface. One solution is to install MOSEK in another location. Another solution is to specify the location of the build folder in a place the user can write to, for example:

python setup.py build --build-base=SOME_FOLDER install --user