# Schema Language

We use [JSON schema](https://json-schema.org/) as the Schema Definition Language as it offers several advantages:

* Easy to describe the structure and semantics of metadata models with readable documentation that is both human and machine consumable.
* Common types can be developed once and can be reused as building blocks in other schemas and become the basis of vocabulary development.
* Models can include structural validation, such as required/optional fields, default values, allowed values, regex that not only serve as automated testing and validation but also as documentation of API contract.
* A rich set of tools are available that supports JSON schema support for generating code and validation from JSON schema in various languages, reducing the manual boilerplate coding.
* Supports rich formats to convert schema types into native standard types during code generation, such as URI, date, and time.

## Reference

1. [JSON schema](https://json-schema.org/) specification version [Draft-07 to 2019-099](https://json-schema.org/draft/2019-09/release-notes.html)
2. [JSON schema 2 POJO](https://www.jsonschema2pojo.org/) tool used for Java code generation from JSON schema
3. [Data model code generator](https://github.com/koxudaxi/datamodel-code-generator) for generating python code from JSON schema

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