Examine source code of Capture From Browser

{
  "manifest_version": 3,
  "name": "Capture From Browser",
  "version": "1.9",
  "description": "Capture title and selection to local backend.",
  "permissions": [
    "activeTab",
    "scripting",
    "storage"
  ],
  "host_permissions": [
    "http://localhost/*",
    "http://127.0.0.1/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "service_worker": "background.js"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "@capture-from-browser.precompute",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "Add Context",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "commands": {
    "_execute_action": {
      "suggested_key": {
        "default": "Alt+Shift+Z"
      },
      "description": "Capture with Context (Popup)"
    },
    "quick-capture": {
      "suggested_key": {
        "default": "Alt+Shift+A"
      },
      "description": "Quick Capture (No Context)"
    }
  }
}