You can discover and play with JSON schema using online tools such as JSON Schema Validator (https://www.jsonschemavalidator.net/) . Such tools allow you to validate a schema against JSON data (such as to perform its data migration, located in tools/shell-commands/src/main/resources/META- INF/cxs/migration (https://github.com/apache/unomi/tree/master/tools/shell-commands/src/main/resources/META-INF/cxs/migration) twice. You can find existing painless scripts in tools/shell-commands/src/main/resources/requestBody/2.0.0 (https://github.com/apache/unomi/tree/master/tools/shell-commands/src/main/resources/requestBody/2