NONCE_TOO_LOW

The transaction nonce is below the account nonce on chain.

HTTP status	409
Group	Relay path
Retryable	No — sending it again changes nothing
Re-sign	NONE — do not ask the user to sign anything

What happened

The sender has moved on: the nonce in the signed transaction can never execute.

What to do

Read details.expectedNonce, rebuild with it, sign once.

Extra members

This code carries onchainNonce, poolLastNonce, expectedNonce in the problem document, on top of the common members.

The problem document

Every error is application/problem+json (RFC 9457) with the same shape:

{
  "type": "https://docs.co-relayer.com/errors/nonce-too-low",
  "title": "The transaction nonce is below the account nonce on chain.",
  "status": 409,
  "detail": "A sentence about this specific occurrence.",
  "instance": "req_01JB…",
  "code": "NONCE_TOO_LOW",
  "retryable": false,
  "resign": "NONE",
  "hint": "Read `details.expectedNonce`, rebuild with it, sign once."
}

See the error model for what each member means and how to handle unknown codes.