# `VALIDATION_FAILED` (HTTP 422): the request body did not pass validation

One or more fields are missing, malformed, or over a limit. error.errors lists each field with its messages.

Typical causes: an email longer than 254 characters, more than 50 addresses in a batch or 100,000 in a bulk job, a callback_url that is not https, callback_secret missing or outside 16 to 128 characters, a bulk results variant that is not full, deliverable, risky or undeliverable, or a feedback outcome that is not delivered, bounced or complained.

Nothing runs and nothing is billed. The errors object is keyed by field name, with array items addressed as emails.3.

**What to do.** Read error.errors, fix the named fields, and resend. Validation rules are listed on each endpoint's reference page.

```json
{
    "success": false,
    "error": {
        "code": "VALIDATION_FAILED",
        "message": "The email field is required.",
        "errors": {
            "email": [
                "The email field is required."
            ]
        },
        "request_id": "req_01m1kgdm4xngzmbmff68g94w0c"
    }
}
```

Reference: https://spaw.co/docs/errors/VALIDATION_FAILED