We'll help you craft the best vendor contract agreement for your specific needs, and help you manage that relationship as long as you need it. An exclusive vendor agreement protects vendors and their customers from working with a competitor and both sells a service or product in a specified market.Our free, downloadable ecommerce terms and conditions template is fully customizable, including the title, and applies to all of the following online stores. A vendor agreement is a legal contract between a vendor (supplier) and a buyer (customer) outlining the terms and conditions of the goods or services provided.