Hi Patrick,

the SDK-Package (Software Development Kit) is a package that includes everything you need to build PLC applications. It aggregates multiple packages that have been tested together for interoperability to ensure your convenience. The SDK-package is released twice a year (e.g. 2504 means released in April 2025).

By default, apax will let you install only packages that fit to the packages already included into your project (I know, pretty smart :)) - meaning if you just add e.g. axunitst in version 8.3.9 to your dependencies, apax install will throw an error.

If you still want to use a different version of a package, that is also possible. The apax.yml file has the attribute overrideDependencies for that. This kind of dependency is used to overrule the decision of Apax. Overriding a dependency here also means using only the sub-dependencies from the specified package version. To see what package versions are excluded from the dependency resolving, you can perform an apax tree.

In your case, you can just add the package to your apax.yml manually:

devDependencies:
  "@ax/sdk": ^2504.0.0
overrideDependencies:
  "@ax/axunitst": ^8.3.9

Afterwards run apax install.

But be careful: If you run in this case, there is no guarantee that all of your used packages and libraries work as expected, since you are using package versions, that might not be tested with the original ones. It is recommended to always have a setting where apax can resolve all your dependencies without overrideDependencies. Siemens cannot ensure that everything works when you do so!

You can find more information on the topic of dependency resolving here: https://console.simatic-ax.siemens.io/docs/apax/dependency_resolving#overridedependencies

Best regards,

Johannes