Examine source code of API Tester Sidebar

{
  "manifest_version": 2,
  "name": "API Tester Sidebar",
  "version": "1.0",
  "description": "Send API requests and view responses from a sidebar.",
  "permissions": [
    "tabs",
    "storage",
    "<all_urls>"
  ],
  "sidebar_action": {
    "default_title": "API Tester",
    "default_panel": "sidebar.html"
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{687e81dd-17c7-421a-b376-faf78889e6a6}"
    }
  }
}