Nessie comes with a simple web UI that allows you to understand what is in your Nessie repository. You can view existing tags and branches as well as the content within them.
The UI automatically runs as part of starting the Nessie service. If running locally, you can find the UI at localhost:19120.
The Swagger UI allows for testing the REST API and reading the API docs. It is available at localhost:19120/q/swagger-ui.