merchant-trap is a free Chrome extension developed by gigasoftpeople that aims to provide users with information about the location of overseas vendors when purchasing items online. The extension is primarily focused on Amazon, as the developers have personally experienced the consequences of not being aware of where their purchases are being delivered from. The goal of the extension is to save users time by alerting them to the location of the item they are about to purchase, thus avoiding lengthy returns, shipping fees, and incorrect replacement parts.

By installing the merchant-trap extension, users can easily discover the country from which the item they are interested in purchasing will be delivered. The extension does not block any purchases but instead queries the vendor's country information and provides users with the relevant information they need. To use the extension, users need to register on the merchant-trap website or via the extension, verify their registration through email, and then log in using the extension. They can then select the countries they would like to be alerted about and proceed to shop on Amazon.

It's important to note that the developer does not use users' registration information for anything other than authentication using their API. Additionally, the developer is actively considering further development for other sites based on user interest. Overall, merchant-trap offers a useful solution for those who want to be more informed about the location of overseas vendors when making online purchases.