Run this command to use a data value and schema file together. You can see if you change a value in the values.yml to be the incorrect type, you will see an error catches this. ytt -f /values.yml -f schema.yml -f template.yml

Generate the OpenAPI schema from the schema.yml file. ytt -f schema.yml --data-values-schema-inspect -o openapi-v3 > openapi-schema.yml

You can use this OpenAPI schema as documentation, or use it in a a kapp-controller Custom Resource, to document what inputs are allowed in the package. ytt -f package-template.yml --data-value-file openapi=openapi-schema.yml > package.yml