Bundler Errors

All ERC-4337 error responses have the following format:

{
  "jsonrpc": "2.0",
  "id": 1
  "error": {
    code,
    message
  }
}

Below are the common error codes specified by the protocol. These are in addition to the standard JSON-RPC error codes returned by a bad method call.

Many of these errors will also be accompanied by an additional error message from the EntryPoint.

Code	Description
-32521	Transaction reverted (or will revert) during execution phase.
-32602	Invalid UserOperation struct/fields.
-32500	Transaction rejected by entryPoint's simulateValidation, during account creation or validation.
-32501	Transaction rejected by paymaster's `validatePaymasterUserOp`.
-32502	Transaction rejected because of opcode validation.
-32503	UserOperation out of time-range: either account or paymaster returned a time-range, and it is already expired (or will expire soon).
-32504	Transaction rejected because paymaster (or signature aggregator) is throttled/banned.
-32505	Transaction rejected because paymaster (or signature aggregator) stake or unstake-delay is too low.
-32506	Transaction rejected because account specified unsupported signature aggregator.
-32507	Either `validateUserOp` or `validatePaymasterUserOp` returned an invalid signature check.