Netdata REST API
The complete documentation of the netdata API is available at the Swagger Editor.
If your prefer it over the Swagger Editor, you can also use Swagger UI. This however does not provide all the information available.
Google charts API
netdata is a Google Visualization API datatable and datasource provider, so it can directly be used with Google Charts.
Check this single chart, jsfiddle example:
and this multi chart, jsfiddle example: