Developer Setup


First install KLayout.

Developer setup may be done independently from the GUI based installation of the KQCircuits Salt package. But you should not do both without removing the other one. Otherwise there will be duplicate macros and possibly other problems.


KQCircuits installation requires Python 3, which should be already installed on Linux. On Windows you may have to install it. If your Python installation does not already contain the pip package manager, you have to also install that.

Successfully tested versions:

  • Ubuntu 18.04, 20.04 and 22.04 LTS with Python 3.6.9, 3.8.5 and 3.10.12

  • Windows: Python 3.7.6, 3.8.5, 3.11


Get KQCircuits’ sources with:

git clone

Alternatively, you may re-use the Salt package itself for quick tests, it is under the .klayout/salt/KQCircuits directory. In this case creating symbolic links or installing some dependencies may not be required. Beware, a Salt package update will overwrite your code in this directory without any warning!


This section explains basic installation, where the required packages are automatically installed in the default locations where KLayout looks for them. If you want to have more control over the installation process, see the next section.

Open a command line / terminal and cd to your KQCircuits folder. Then write:


to install KQC. You may have to write python or py instead of python3 depending on your OS and Python installation, just make sure that the command refers to Python 3.

If your Python installation does not already contain the pip package manager, you have to also install that too.

Note, that KLayout will run macros with it’s own Python version, ignoring virtualenv settings. KLayout is linked together with libpython*.so on Linux and libpython*.dll on Windows.


If KQCircuits is not working properly after installation (KQC libraries not visible, running any macro gives an error, etc.), there might be some problem with the specific KLayout version/build you are using, see Known installation issues section for possible solutions.


Installation command links your KQCircuits installation with your KLayout installation automatically. If you wish to unlink, then write in your terminal:

python3 --unlink


Updating an existing KQCircuits setup is easy. After updating KQCircuits code itself with git pull just run again. This will take care of upgrading (or downgrading) KQCircuits’ Python dependencies and installing new ones, as needed. Running KLayout will similarly update KQCircuits’ dependencies in its own Python environment.

If the above didn’t work (usually in case of downgrading dependencies), there is an alternative way. If you see warnings displaying WARNING: Target directory xyz already exists. Specify --upgrade to force replacement., this usually indicates that KQCircuits’ Python dependencies were not properly upgraded (or downgraded). In that case run the following:

python3 –force-package-reinstall


If a new version of KQCircuits has stopped using a certain Python dependency that will not be removed automatically. The user has to remove that manually if it causes any problem.

Secondary install


Don’t do it, unless you really need multiple parallel environments.

It is possible to work with several independent KQC instances simultaneously. You only need to check out KQCircuits under some different name:

git clone KQC_2nd

KLayout needs to know about this secondary environment, for example:

KLAYOUT_HOME=~/.klayout_alt/KQC_2nd klayout

Remember to set up a new venv before attempting KLayout Standalone Usage in this directory. Otherwise your secondary environment may get mixed up with the primary one.

Manual installation

To use KQCircuits in KLayout Editor, symlinks must be created from KLayout’s python folder to your KQCircuits folder. Some Python packages must also be installed for KQCircuits to work. The details of these steps for different operating systems are explained in the following subsections. The script used in the previous section attempts to automatically do the same steps as explained below.

Linux or MacOS

Create a symlink from KLayout to the kqcircuits package and scripts:

ln -s /Path_to_KQCircuits/klayout_package/python/kqcircuits ~/.klayout/python/kqcircuits
ln -s /Path_to_KQCircuits/klayout_package/python/scripts ~/.klayout/python/kqcircuits_scripts

To install the required packages, open a terminal in your KQCircuits folder (which contains requirements_within_klayout_unix.txt), and write:

pip3 install -r requirements_within_klayout_unix.txt

The previous command installs the packages to your system’s default Python environment, because that is where KLayout looks for the packages on Linux. If you want to install the packages in a separate environment instead, you have to create a symlink to there.


Create a symlink from KLayout to kqcircuits by opening a command prompt with administrator privileges, and do:

cd %HOMEPATH%\KLayout\python
mklink /D kqcircuits "Path_to_KQCircuits\klayout_package\python\kqcircuits"
mklink /D kqcircuits_scripts "Path_to_KQCircuits\klayout_package\python\scripts"

(In PowerShell replace the first line by cd ~\KLayout\python)

Install the required packages by opening command prompt in your KQCircuits folder (which contains requirements_within_klayout_windows.txt), and writing:

pip install -r requirements_within_klayout_windows.txt --target=%HOMEPATH%\AppData\Roaming\KLayout\lib\python3.7\site-packages

(replace python3.7 in this path by the python version used by your KLayout version)

The previous command installs the packages to KLayout’s embedded Python environment, which is where KLayout looks for packages on Windows. If you want to install the packages in another environment instead, you have to create a symlink to there.

Some packages, like numpy, must be compiled on the same compiler as the embedded Python in KLayout. Since KLayout 0.26.2, a correct version of numpy is already included with KLayout, so this shouldn’t be a problem.