Cancel a bid

MEV Blocker provides bundle cancellation features. You can cancel a previously submitted bundle using either of the following methods. Both methods require the replacementUuid that was used when the bundle was originally submitted.

Option 1: Cancel using eth_sendBundle

To cancel a previously submitted bundle, send an empty bundle to eth_sendBundle with the same replacementUuid.

Example request

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "eth_sendBundle",
  "params": [
    {
      "txs": [],  // Empty array to cancel the bundle
      "replacementUuid": "blinklabsxyz"  // Same UUID as the bundle you want to cancel
    }
  ]
}

Example response

{
  "id": 1,
  "jsonrpc": "2.0",
  "result": "0x164d7d41f24b7f333af3b4a70b690cf93f636227165ea2b699fbb7eed09c46c7"
}

Option 2: Cancel using eth_cancelBundle

Cancel a bundle using the eth_cancelBundle method. This method supports an empty bundle with the UUID you want to cancel.

Use either:

• Websocket: wss://searchers.mevblocker.io
• HTTP RPC: https://rpc.mevblocker.io

Example request

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "eth_cancelBundle",
  "params": [
    {
      "replacementUuid": "mevblocker"   // String, any arbitrary string that can be used to replace or cancel this bundle
    }
  ]
}

Example response

A successful response returns 200:

{
  "id": 1,
  "jsonrpc": "2.0",
  "result": 200
}

Next steps

Consider following these next steps:

• Learn how to bid on transactions.
• See the eth_sendBundle method for API details.
• See the eth_cancelBundle method for API details.
• Learn how to listen for transactions.