Examine source code of Himitsu

{
  "author": "Drew DeVault et al",
  "description": "Himitsu integration for Firefox",
  "manifest_version": 2,
  "name": "himitsu",
  "version": "0.9",
  "homepage_url": "https://sr.ht/~sircmpwn/himitsu",
  "browser_specific_settings": {
    "gecko": {
      "id": "himitsu@drewdevault.com",
      "strict_min_version": "58.0"
    }
  },
  "icons": {
    "512": "icons/lock-512.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content/content.js"
      ],
      "run_at": "document_idle",
      "all_frames": false
    }
  ],
  "background": {
    "scripts": [
      "content/background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "nativeMessaging",
    "http://*/*",
    "https://*/*"
  ],
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "512": "icons/lock-512.png"
    },
    "default_title": "Click to auto-fill passwords from Himitsu"
  }
}