API errors
Bad request
The request could not be parsed at the framework level, before schema validation even started. Nothing was processed or billed. A well-formed JSON body that merely violates the schema returns the more specific invalid-request error instead.
- Error type
https://normbill.com/docs/errors/bad-request- HTTP status
- 400
Common causes
- The body is not valid JSON — a syntax error, a truncated payload, or an empty body.
- The Content-Type is not application/json (the body was sent as text or form data). Unsupported media types are reported here too.
- The request was otherwise malformed before it reached the invoice endpoints.
How to fix it
- Send a well-formed JSON body with the header Content-Type: application/json.
- If your JSON is valid but a field is wrong, work from the invalid-request error and its errors array instead.
- Check for accidental double-encoding, or a proxy that rewrote the request body.
The error response format
Every non-2xx response from the API is an RFC 9457 problem-details body (application/problem+json) with at least type, title, status and detail. The type URL links back to this reference.
All error slugs: invalid-request, bad-request, payload-too-large, unauthorized, validation-failed, unparseable-document, plan-limit, quota-exceeded, rate-limited, overage-cap-reached, validate-fair-use, idempotency-key-invalid, idempotency-key-reuse, idempotency-conflict, pdf-unavailable, validator-unavailable, not-ready. Still stuck? Email support@normbill.com or start at the docs overview.