API Test Base application stores data in a folder called <APITestBase_Data>. To open this folder, locate the application’s system tray icon, click it and select Open Data Folder.

The first time you launch the application, two new folders are created automatically under the <APITestBase_Data> folder.

database - where system database and a sample database are located. Both are H2 databases. 
    System database is used to store all test cases, environments, endpoints, etc. you create using API Test Base.
    Sample database is for you to play with API Test Base basic features such as REST API testing or database testing. An Article table is in it.

logs - where API Test Base application runtime logs are located.

It is recommended that you back up <APITestBase_Data>/database folder regularly. Remember to exit the application before backing up.

You can tune API Test Base application to suit your runtime needs by changing contents of the config.yml under <APITestBase_Data>. For example, you can change the UI port number through the property server > applicationConnectors > port in config.yml. Refer to Dropwizard doc for more information. Re-launch API Test Base for the changes to take effect.