JavaScript Browser (Analytics.js)

To integrate Segment's JavaScript SDK with a custom API host:

AnalyticsBrowser.load(
  {
    writeKey: '<EVEFAN_SOURCE_WRITE_KEY>',
    cdnUrl: '<EVEFAN_WORKER_HOST>'
  }, 
  {
    integrations: {
      "Segment.io": {
        apiHost: '<EVEFAN_WORKER_HOST>/v1'
      },
    },
  }
);

Here's their get started guide.