REPLACEMENT_UNDERPRICED

The replacement transaction does not pay enough to displace the one in the pool.

HTTP status	422
Group	Relay path
Retryable	No — sending it again changes nothing
Re-sign	NONE — do not ask the user to sign anything

What happened

Its gas price is at or below the gas price of the transaction that already occupies the nonce.

What to do

Sign a replacement with at least details.minGasPrice, or wait for the pending one to execute.

Extra members

This code carries minGasPrice 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/replacement-underpriced",
  "title": "The replacement transaction does not pay enough to displace the one in the pool.",
  "status": 422,
  "detail": "A sentence about this specific occurrence.",
  "instance": "req_01JB…",
  "code": "REPLACEMENT_UNDERPRICED",
  "retryable": false,
  "resign": "NONE",
  "hint": "Sign a replacement with at least `details.minGasPrice`, or wait for the pending one to execute."
}

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