Fira Sans / 400
{
  "copyright": {
    "en": "Digitized data copyright 2012-2016, The Mozilla Foundation and Telefonica S.A."
  },
  "license": {
    "en": "Licensed under the Open Font License, version 1.1 or later"
  },
  "licenseURL": {
    "en": "http://scripts.sil.org/OFL"
  }
}

Fira Sans / 600
{
  "copyright": {
    "en": "Digitized data copyright 2012-2016, The Mozilla Foundation and Telefonica S.A."
  },
  "license": {
    "en": "Licensed under the Open Font License, version 1.1 or later"
  },
  "licenseURL": {
    "en": "http://scripts.sil.org/OFL"
  }
}

Fira Sans / 700
{
  "copyright": {
    "en": "Digitized data copyright 2012-2016, The Mozilla Foundation and Telefonica S.A."
  },
  "license": {
    "en": "Licensed under the Open Font License, version 1.1 or later"
  },
  "licenseURL": {
    "en": "http://scripts.sil.org/OFL"
  }
}