Vega-Lite API

A JavaScript API for creating Vega-Lite JSON specifications. Vega-Lite is a high-level grammar for visual analysis that generates complete Vega specifications.

With the Vega-Lite API, you can write JavaScript code like this:

vl.markBar().data('data/movies.json').encode(
  vl.x().fieldQ('IMDB_Rating').bin(true),
  vl.y().count()
)

To produce Vega-Lite JSON like this:

{
  "mark": "bar",
  "data": {"url": "data/movies.json"},
  "encoding": {
    "x": {
      "bin": true,
      "field": "IMDB_Rating",
      "type": "quantitative"
    },
    "y": {
      "aggregate": "count",
      "type": "quantitative"
    }
  }
}

To get started with the Vega-Lite API, see these Observable notebooks:

• Introduction to Vega-Lite
• Vega-Lite API

Build Instructions

For a basic setup allowing you to build the API and run tests:

• Clone https://github.com/vega/vega-lite-api.
• Run yarn to install dependencies for all packages. If you don't have yarn installed, see https://yarnpkg.com/en/docs/install.
• Once installation is complete, run yarn build to build the API generator and generate API source code in the src directory. Run yarn test to additionally run the test suite.

API Reference

See the Vega-Lite JavaScript API Reference.