Examine source code of Beyond 20

{
  "name": "Beyond 20",
  "version": "2.20.1",
  "manifest_version": 2,
  "description": "Integrates the D&D Beyond Character Sheets with Roll20 and Foundry VTT.",
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "*://beyond20.kicks-ass.org/roll",
    "*://app.roll20.net/editor/",
    "*://*.dndbeyond.com/*",
    "*://*.forge-vtt.com/game"
  ],
  "optional_permissions": [
    "*://*/",
    "webNavigation"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "beyond20@kakaroto.homelinux.net"
    }
  },
  "icons": {
    "16": "images/icons/icon16.png",
    "24": "images/icons/icon24.png",
    "32": "images/icons/icon32.png",
    "48": "images/icons/icon48.png",
    "64": "images/icons/icon64.png",
    "128": "images/icons/icon128.png",
    "256": "images/icons/icon256.png"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "browser_action": {
    "default_popup": "default_popup.html",
    "default_icon": {
      "16": "images/icons/icon16.png",
      "24": "images/icons/icon24.png",
      "32": "images/icons/icon32.png"
    }
  },
  "web_accessible_resources": [
    "images/*",
    "libs/css/alertify.css",
    "libs/css/alertify-themes/default.css",
    "libs/css/alertify-themes/beyond20.css",
    "libs/alertify.min.js",
    "libs/jquery-3.4.1.min.js",
    "libs/lz-string.min.js",
    "dist/roll20_script.js",
    "dist/fvtt_script.js",
    "dist/dndbeyond_mb.js",
    "popup.html",
    "options.html"
  ],
  "background": {
    "persistent": true,
    "scripts": [
      "dist/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.dndbeyond.com/*characters/*",
        "*://*.dndbeyond.com/characters"
      ],
      "css": [
        "dist/beyond20.css"
      ],
      "js": [
        "libs/jquery-3.4.1.min.js",
        "dist/dndbeyond_character.js"
      ],
      "all_frames": true
    },
    {
      "matches": [
        "*://*.dndbeyond.com/monsters/*"
      ],
      "css": [
        "dist/beyond20.css"
      ],
      "js": [
        "libs/jquery-3.4.1.min.js",
        "dist/dndbeyond_monster.js"
      ],
      "all_frames": true
    },
    {
      "matches": [
        "*://*.dndbeyond.com/vehicles/*"
      ],
      "css": [
        "dist/beyond20.css"
      ],
      "js": [
        "libs/jquery-3.4.1.min.js",
        "dist/dndbeyond_vehicle.js"
      ],
      "all_frames": true
    },
    {
      "matches": [
        "*://*.dndbeyond.com/spells/*"
      ],
      "css": [
        "dist/beyond20.css"
      ],
      "js": [
        "libs/jquery-3.4.1.min.js",
        "dist/dndbeyond_spell.js"
      ],
      "all_frames": true
    },
    {
      "matches": [
        "*://*.dndbeyond.com/my-encounters",
        "*://*.dndbeyond.com/encounters/*",
        "*://*.dndbeyond.com/combat-tracker/*"
      ],
      "css": [
        "dist/beyond20.css"
      ],
      "js": [
        "libs/jquery-3.4.1.min.js",
        "dist/dndbeyond_encounter.js"
      ],
      "all_frames": true
    },
    {
      "matches": [
        "*://*.dndbeyond.com/equipment/*",
        "*://*.dndbeyond.com/magic-items/*"
      ],
      "css": [
        "dist/beyond20.css"
      ],
      "js": [
        "libs/jquery-3.4.1.min.js",
        "dist/dndbeyond_item.js"
      ],
      "all_frames": true
    },
    {
      "matches": [
        "*://*.dndbeyond.com/feats/*"
      ],
      "css": [
        "dist/beyond20.css"
      ],
      "js": [
        "libs/jquery-3.4.1.min.js",
        "dist/dndbeyond_feat.js"
      ],
      "all_frames": true
    },
    {
      "matches": [
        "*://*.dndbeyond.com/sources/*",
        "*://*.dndbeyond.com/classes/*",
        "*://*.dndbeyond.com/races/*",
        "*://*.dndbeyond.com/species/*",
        "*://*.dndbeyond.com/backgrounds/*"
      ],
      "exclude_matches": [
        "*://*.dndbeyond.com/classes/*/edit",
        "*://*.dndbeyond.com/races/*/edit",
        "*://*.dndbeyond.com/species/*/edit",
        "*://*.dndbeyond.com/backgrounds/*/edit"
      ],
      "css": [
        "dist/beyond20.css"
      ],
      "js": [
        "libs/jquery-3.4.1.min.js",
        "dist/dndbeyond_source.js"
      ],
      "all_frames": true
    },
    {
      "matches": [
        "*://app.roll20.net/editor/*"
      ],
      "css": [
        "libs/css/alertify.css",
        "libs/css/alertify-themes/default.css",
        "libs/css/alertify-themes/beyond20.css"
      ],
      "js": [
        "libs/alertify.min.js",
        "libs/jquery-3.4.1.min.js",
        "dist/roll20.js"
      ]
    }
  ]
}