Examine source code of CryptoMessenger

{
  "manifest_version": 3,
  "name": "CryptoMessenger",
  "version": "1.0",
  "description": "Client-side public/private key message encryption.",
  "permissions": [
    "activeTab",
    "storage",
    "scripting",
    "contextMenus"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "cryptomessenger@yourproject.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "action": {
    "default_popup": "popup.html"
  }
}