Hero is developed as an online tool (http://www.hero-go.com/) to help Golang developers deal with dependency management (DM) issues, by automatically diagnosing their root causes and customizing fixing suggestions. Its main features are: 1) constructing and visualizing a dependency model for a Golang project under test; Specially, the dependency model shows the dependency relationships among the client project’s downstream and upstream projects and their corresponding library-referencing modes; 2) diagnosing DM issues; 3) providing their detailed root causes and customized fixing solutions with analyses of potential benefits and consequences incurring to the ecosystem if certain fixing solutions are taken. For more detailed information, please refer to the "ABOUT" page of Hero.