curl --request POST \
  --url https://app.formbricks.com/api/v3/surveys/validate \
  --header 'Content-Type: application/json' \
  --cookie next-auth.session-token= \
  --data '
{
  "operation": "create",
  "data": {
    "workspaceId": "clxx1234567890123456789012",
    "name": "Product Feedback Survey",
    "defaultLanguage": "en-US",
    "blocks": [
      {
        "id": "clbk1234567890123456789012",
        "name": "Main Block",
        "elements": [
          {
            "id": "satisfaction",
            "type": "openText",
            "headline": {
              "en-US": "What should we improve?"
            },
            "required": true
          }
        ]
      }
    ]
  }
}
'

{
  "data": {
    "valid": false,
    "operation": "create",
    "invalid_params": [
      {
        "name": "blocks.0.elements.0.buttonUrl",
        "reason": "Unsupported field 'buttonUrl' for element type 'openText'. Allowed fields..."
      }
    ]
  }
}