Azure DevOps: Upstream sources

With upstream sources, you can use a single feed to store the packages you generate and the packages you consume from public registries such as npmjs.com, NuGet.org, Maven Central, and PyPI.org. Once you've enabled an upstream source, every time you install a package from the public registry, Azure Artifacts will save a copy of that package in your feed.

https://learn.microsoft.com/en-us/azure/devops/artifacts/tutorials/protect-oss-packages-with-upstream-sources?view=azure-devops&tabs=npm%2Cnpmrestore

https://learn.microsoft.com/en-us/azure/devops/artifacts/concepts/upstream-behavior?view=azure-devops&tabs=nuget%2Cget