How to restrict json schema to not support a particular data type

Question

I want to restrict my application to only support "string" type values for json configuration. Json schema by default supports a set of datatypes such as integer, boolean, etc however, the parsing logic in my application only supports string values.

How do I make sure the schema does not define a property of any type except string.

Allow - { "key1": "A", "key2": "B" }

Reject - { "key1": "A", "key2": true} or { "key1": "A", "key2": ["1","2"]}

Answer 1

This would be the most basic example to match your requirements. Each property defines a type (data type). This type keyword is the constraint applied to that property

{
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "description": "a basic schema",
    "type": "object",
    "properties": {
        "key1": {
            "type": "string"
        },
        "key2": {
            "type": "string"
        }
    }
}

Take a look at this fundamentals post from the JSON Schema blog for a nice introduction to understanding JSON Schema.