Adding a custom End User Licence Agreement (EULA) to package downloads in a Cloudsmith repository is straightforward. A EULA allows developers to specify the terms and conditions under which their software can be used, distributed, and modified by end-users. By adding a custom EULA to their repository, developers can ensure that their users comply with specific rules and restrictions, protecting their intellectual property and brand reputation. This process does not require extensive technical knowledge or coding expertise, making it easily accessible to developers of all skill levels.