gengojs-default-header/defaults/index.json

The default header plugin for gengojs

{
  "detect": {
    "query": false,
    "subdomain": false,
    "url": false,
    "cookie": false,
    "header": true
  },
  "keys": {
    "cookie": "locale",
    "query": "locale"
  },
  "supported": ["en-US"],
  "default": "en-US"
}