You can use this package to interact with the Actions artifacts.
This most recently published version of this package (1.1.1) can be found here
This package is currently undergoing a major overhaul in preparation for v4 versions of upload-artifact and download-artifact (these Actions will use a new 2.0.0 version of @actions/artifact that will soon be released). The upcoming version of @actions/artifact will take advantage of a major re-architecture with entirely new APIs.
The upcoming 2.0.0 package and v4 artifact Actions aim to solve some of the major pain-points that have made artifact usage difficult up until now.