Salt Package Guide

A stable version of KQCircuits is often released as an easily accessible KLayout Salt Package.

Installing KQCircuits Salt Package

Select “Tools -> Manage Packages” in the KLayout menu to install the KQCircuits package:


Note that KLayout was started in edit mode, see Usage.


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.

User Specific Content

KLayout Salt packages are read-only. The user may open the code (say, [Package KQCircuits]/kqcircuits/chips/simple) with the embedded macro editor (F5) but it can not be directly changed here. Of course, external code editors may be used to change these files or their copies, but Salt package upgrades will override these changes.

Users may extend KQCircuits with their own Python packages using KQCircuits -> Add User Package menu entry. Packages have a name and a directory linked to it. Remove User Package will undo the linking without deleting the user created files. Package name should be a single lowercase word. Remember to restart KLayout after adding or removing a user specific Python package.

PCell files should be added under the individual library directories using your favourite code editor providing additional elements, chips etc. After adding or editing a file remember to use Reload libraries menu entry so that it shows correctly in KLayout.

For example create a user package, this (by default) will be linked to a user directory in your home folder. Copy KQC’s to user/elements/ then edit this file and change the FingerCapacitorSquare class name to MyCapacitor. After restarting KLayout the newly added MyCapacitor element will be available together with the standard KQCircuits elements. Afterwards you may create a copy of chip, rename it and change the capacitors using from user.elements.my_capacitor import MyCapacitor. After reloading the libraries your new chip will appear using your new capacitor.

Upgrading or Removing Salt Package

After upgrading KQCircuits package KLayout needs to be restarted. See the release notes for further details.

Downgrading or upgrading several steps at once is not guaranteed to always work. Upgrading KQC usually works but the safest approach is to uninstall KQC and then install a new version.

For serious development work we suggest removing the Salt package and following the Developer Setup.

Release Notes

Here we list particular quirks of specific KQCircuits Salt packages. For a full list of changes see the code repository.

  • Version 4.5.0 is broken

  • Version 4.1.0 requires full reinstall of KQC. Qubits directory has moved, to remove the earlier version we need to first remove KQC then install the new version.

  • Version 4.0.0 requires full reinstall of KQC. Several files have been relocated, without a full reinstall multiple versions of the same file will be left behind.

  • Version 3.3.0 needs manual install of tqdm Python module.