Custom Properties in JSON Schema
<p>Is it valid to extend a JSON schema with custom properties?</p>

<p>The reason I am asking is, because I am using a schema to also render a form for the JSON the schema describes (each property described in the schema is  used as a form element with label and some sort of input).</p>

<p>It would be useful to be able to extend the schema with some properties that I mainly use for the form rendering, but that would be ignored when using the schema to validate the JSON object itself.</p>

<p>I could have two different representations for the JSON object (one being the schema and one being the schema like object with custom properties that I just for creating the form, but it would be easier for maintenance if I can combine both in one).</p>

<p>Unfortunately Google wasn't very helpful and I don't have a huge amount of experience using JSON schemas, so apologies if I am missing something obvious. </p>

<p><strong>Edit 1:</strong><br>
Example Schema Snippet: </p>

<pre><code>{
    "title": "Example Schema",
    "type": "object",
    "properties": {
        "firstName": {
            "type": "string",
            "CUSTOM_PROPERTY": "CUSTOM_VALUE"
        }
    }
}
</code></pre>

<p>Note the above is just a snippet and hence doesn't have <code>title</code>, <code>$schema</code> etc.</p>