Examine source code of Magic Cart

{
  "name": "Magic Cart",
  "manifest_version": 2,
  "version": "1.0.2",
  "description": "add missing add to cart button",
  "permissions": [
    "webRequest",
    "*://*.amd.com/"
  ],
  "icons": {
    "128": "icons/icon_128.png"
  },
  "content_scripts": [
    {
      "js": [
        "amd.js"
      ],
      "matches": [
        "*://*.amd.com/*"
      ],
      "run_at": "document_end"
    }
  ],
  "background": {
    "scripts": [
      "bg.js"
    ],
    "persistent": true
  }
}