Examine source code of GraphQL Playground

{
  "manifest_version": 2,
  "name": "GraphQL Playground",
  "version": "1.0",
  "description": "A GraphQL Playground browser extension to test GraphQL queries.",
  "icons": {
    "48": "icon.png"
  },
  "permissions": [
    "tabs",
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "GraphQL Playground"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e734610c-2a4a-4a93-b639-f75ac1021c0e}"
    }
  }
}