Examine source code of Instapaper

{
  "manifest_version": 3,
  "name": "Instapaper",
  "description": "Instapaper browser extension to save links for offline reading.",
  "version": "3.1.3",
  "options_ui": {
    "page": "options.html"
  },
  "icons": {
    "16": "img/insta_logo_tiny.png",
    "48": "img/insta_logo_small.png",
    "128": "img/insta_logo.png"
  },
  "commands": {
    "ctrl-shift-s": {
      "suggested_key": {
        "default": "Ctrl+Shift+I"
      },
      "description": "Save article"
    }
  },
  "permissions": [
    "storage",
    "activeTab",
    "contextMenus"
  ],
  "host_permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "background": {
    "scripts": [
      "js/readlater.js"
    ]
  },
  "action": {
    "default_icon": {
      "16": "img/insta_logo_small.png",
      "32": "img/insta_logo_small@2x.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "exclude_matches": [
        "https://instapaper.com/read/*",
        "https://*.instapaper.com/read/*"
      ],
      "js": [
        "js/bookmarklet.js",
        "js/deflate-base64-min.js",
        "js/highlights-ugly.js",
        "js/premium.js",
        "js/tags.js"
      ],
      "css": [
        "css/instapaper.css",
        "css/ipicons.css",
        "css/highlights.css",
        "css/premium.css",
        "css/tags.css"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "http://twitter.com/*",
        "https://twitter.com/*",
        "http://x.com/*",
        "https://x.com/*"
      ],
      "js": [
        "js/twitter.js"
      ]
    },
    {
      "matches": [
        "https://news.ycombinator.com/*"
      ],
      "js": [
        "js/hackernews.js"
      ]
    },
    {
      "matches": [
        "https://lobste.rs/*"
      ],
      "js": [
        "js/lobsters.js"
      ]
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "img/*.png",
        "img/*.svg"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d0210f13-a970-4f1e-8322-0f76ec80adde}",
      "strict_min_version": "109.0"
    }
  }
}