How can I add a title to c3.js chart

This was a top google result, so I thought I'd add that this is now part of the library:

title: {
  text: 'My Title'
}

More info @ https://github.com/masayuki0812/c3/pull/1025

You'd need to fall back to using D3 to add a chart title. Something like:

d3.select("svg").append("text")
    .attr("x", 100 )
    .attr("y", 50)
    .style("text-anchor", "middle")
    .text("Your chart title goes here");