How to do a basic JSON Schema sanity check against data

1. Paste the schema

   Drop your JSON Schema into the "Schema" field. The tool only looks at `type` ("object" / "array" / "string" / "number" / "boolean" / "null") and `required` (array of property names). Other keywords like `properties`, `enum`, `pattern`, `format`, `minimum`, `items` are NOT enforced.

2. Paste the JSON data

   Drop the candidate document into the "Data" field. Both fields must be valid JSON — syntax errors throw "Invalid Schema JSON." or "Invalid Data JSON." before validation runs.

3. Press Run

   Result returns `valid` (boolean) plus `errors` (array of strings). Errors look like "Type mismatch: expected number" or "Missing required: id". Empty `errors` and `valid: true` mean the smoke test passes.

4. When you need a real validator

   This is a smoke test, not a Draft-2020-12 implementation. For full Schema features ($ref, allOf/anyOf, format checks, conditionals) use a real library like ajv on a server or in Node — the precise feedback there is worth it.