Examine source code of Just Save

{
  "manifest_version": 2,
  "name": "Just Save",
  "version": "0.0.3resigned1",
  "description": "A simple WebExtension for skipping the \"Save As\" dialog when saving images, pages and links.",
  "icons": {
    "48": "icons/just-save-48.png",
    "96": "icons/just-save-96.png"
  },
  "applications": {
    "gecko": {
      "id": "just-save@lewisl.webextension",
      "strict_min_version": "45.0"
    }
  },
  "background": {
    "persistent": false,
    "scripts": [
      "just-save.js"
    ]
  },
  "permissions": [
    "contextMenus",
    "downloads"
  ]
}