SIMULATION_FAILED

Pre-flight simulation says the transaction would fail on chain.

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

The node returned an error for the simulated execution; relaying it would burn quota and gas for nothing.

What to do

Read details.returnMessage, fix the call, and sign a corrected transaction.

Extra members

This code carries returnMessage 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/simulation-failed",
  "title": "Pre-flight simulation says the transaction would fail on chain.",
  "status": 422,
  "detail": "A sentence about this specific occurrence.",
  "instance": "req_01JB…",
  "code": "SIMULATION_FAILED",
  "retryable": false,
  "resign": "NONE",
  "hint": "Read `details.returnMessage`, fix the call, and sign a corrected transaction."
}

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