In IManifestFilter there is a property called PackageId. What am I supposed to put in there? Just a fixed guid, or something else?

Is this prior to v14 as I dont think manifest filters are a v14 thing anymore. But from my memory isn't it just a unique package id, same as you would for nuget package id. Believe its used for Umbraco's analytics stuff to see what packages are installed and the marketplace stuff

AFAIK it's just a string for your (unique) package name https://docs.umbraco.com/umbraco-dxp/marketplace/listing-your-package#synchronization-with-nuget-and-package-owner-data

The

PackageId

property should indeed be aligned with your NuGet package ID, so there's a 1:1 mapping to your unique package (as package names can easily collide with others). This is mainly used for our telemetry data, so the Marketplace can properly attribute usage data for your package. This package ID can also be set on your

PackageMigrationPlan

(if you have one), so Umbraco can combine the migration plan with your package manifest. This will also show up in the backoffice Packages > Installed overview.

I did guess right then 😛