Examine source code of Usable Browser Agent (free)

{
  "manifest_version": 2,
  "name": "Usable Browser Agent (free)",
  "version": "0.7.0",
  "description": "Lets a local AI agent (Claude Code / Codex) drive this Firefox browser, using your real logged-in sessions. Free for personal use and evaluation.",
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png",
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "usable-browser-agent-free@local",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "tabs",
    "activeTab",
    "<all_urls>",
    "webNavigation",
    "cookies",
    "scripting",
    "clipboardRead",
    "clipboardWrite",
    "downloads",
    "webRequest",
    "webRequestBlocking",
    "notifications"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "early.js"
      ],
      "run_at": "document_start",
      "all_frames": true,
      "match_about_blank": true
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle",
      "all_frames": true,
      "match_about_blank": true
    }
  ],
  "browser_action": {
    "default_title": "Usable Browser Agent",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon-16.png",
      "32": "icon-32.png",
      "48": "icon-48.png",
      "128": "icon-128.png"
    }
  }
}