json-schema.org

Here is a basic example of a JSON Schema:

{
	"title": "Example Schema",
	"type": "object",
	"properties": {
		"firstName": {
			"type": "string"
		},
		"lastName": {
			"type": "string"
		},
		"age": {
			"description": "Age in years",
			"type": "integer",
			"minimum": 0
		}
	},
	"required": ["firstName", "lastName"]
}

The two examples below are step-by-step guides into building a schema:

• a simple example which covers a classical product catalog description.
• a more advanced example, using JSON Schema to describe filesystem entries in a Unix-like /etc/fstab file.

The Space Telescope Science Institute has also published an guide aimed at schema authors.