Can I use Vega Lite with multiple indexes?

I have a use case which data sources are from two separated indexes, is it possible to plot a single chart from two indexes by vega? Thanks

It's possible to do this in vega, but not in vega-lite.

In vega, simply pass an array of { url: {...}, name: "sourcename" } objects to data and you will be able to use them in the chart.