JSON - Schema

Schema

JSON Schema is a specification for a JSON-based format for defining the structure of JSON data. JSON Schema provides a contract for what JSON data is required for a given application and how it can be modified, much like the XML Schema provides for XML. JSON Schema is intended to provide validation, documentation, and interaction control of JSON data. JSON Schema is based on the concepts from XML Schema, RelaxNG, and Kwalify, but is intended to be JSON-based, so that JSON data in the form of a schema can be used to validate JSON data, the same serialization/deserialization tools can be used for the schema and data, and it can be self descriptive.

JSON Schema was written up as an IETF draft, which expired in 2011. However, there are several validators currently available for different programming languages, each with varying levels of conformance. Currently the most complete and compliant JSON Schema validator available is JSV.

Example JSON Schema:

{ "name": "Product", "properties": { "id": { "type": "number", "description": "Product identifier", "required": true }, "name": { "type": "string", "description": "Name of the product", "required": true }, "price": { "type": "number", "minimum": 0, "required": true }, "tags": { "type": "array", "items": { "type": "string" } }, "stock": { "type": "object", "properties": { "warehouse": { "type": "number" }, "retail": { "type": "number" } } } } }

The JSON Schema above can be used to test the validity of the JSON code below:

{ "id": 1, "name": "Foo", "price": 123, "tags":, "stock": { "warehouse": 300, "retail": 20 } }