Card Codex Scanner processes card images entirely in your browser. Screenshots you capture are used only to identify the card on your device and are never uploaded. The extension contacts cardcodex.com to download the public price list, and api.frankfurter.dev to fetch public currency exchange rates so prices can be shown in your chosen currency. Neither request includes any personal information. If you choose to use "Import to my collection", the card IDs and quantities you selected are sent to cardcodex.com so you can confirm the import while signed in there. Your scanned-card list is stored locally in your browser. Affiliate links to eBay and TCGplayer are clearly labelled.