bex_cancelBundle

Cancel a previously submitted BEX bundle identified by its replacementUuid. The bundle will not be executed in any future block.

Requires the X-Flashbots-Signature header. The signing key must match the one used when the bundle was submitted.

Parameters

Field	Type	Required	Description
replacementUuid	string	Yes	The UUID of the BEX bundle to cancel

Request

{
  "jsonrpc": "2.0",
  "method": "bex_cancelBundle",
  "params": [{
    "replacementUuid": "550e8400-e29b-41d4-a716-446655440000"
  }],
  "id": 1
}

Response

Returns true on success:

{
  "jsonrpc": "2.0",
  "result": true,
  "id": 1
}

Errors

Code	Message	Cause
-32602	X-Flashbots-Signature required for cancellation	Missing or invalid auth header

Notes

• Only bundles submitted with a replacementUuid can be cancelled.

• Cancellation is best-effort — if the builder has already committed the execute transaction to a block in progress, it may not be cancellable.