Validation errors | quickforms

JSON clients get the standard Laravel 422 shape: a summary message and an errors object keyed by field name.

422 Unprocessable Contentjson

{
  "message": "The email field must be a valid email address. (and 2 more errors)",
  "errors": {
    "email": ["The email field must be a valid email address."],
    "plan": ["The selected plan is invalid."],
    "seats": ["The seats field must be at least 1."]
  }
}

Messages use the field label in lower case, or the field’s custom message when it has one.
Errors for list fields can be keyed by item, for example topics.0. The embed widget shows them on the parent field.
HTML posts get the hosted error page with the same messages, a 422 status and a link back.
Test submissions through the API and MCP are validated the same way and return the same errors.