Reference

Creating and retrieving blocks Use these functions to create and retrieve blocks. The blocks service uses GitHub gists, so you will need a GitHub account, as well as a Personal Access Token (PAT). If want to include preview and thumb images with the block, you will need nodejs installed on your system, and the processx and magick packages.
vw_create_block() vw_create_block_gistid()	Create gist to use as block
vw_retrieve_block()	Retrieve vegaspec from block
vw_block_config()	Specify block-configuration
vegawidget utilities These functions are imported from the vegawidget package, and re-exported from this package.
as_vegaspec	Coerce to vegaspec
vega_embed	Vega embed options
vega_version	Determine Vega JavaScript versions