Here is a basic example of a JSON Schema:

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

Example schemas

These sample schemas describe simple data structures which can be expressed as JSON:

Geographic Coordinate
(canonical url)
a location as longitude and latitude
Card
(canonical url)
a microformat-style representation of a person, company, organization, or place
Calendar
(canonical url)
a microformat-style representation of an event
Address
(canonical url)
a microformat-style representation of a street address

Walkthroughs

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

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