eth_sendBundle

Submit an atomic bundle of transactions to be included in a specific block. Compatible with the Flashbots eth_sendBundle spec.

Requires the X-Flashbots-Signature header.

Parameters

A single object with the following fields:

Field	Type	Required	Description
txs	string[]	Yes	Array of signed transactions, each as a 0x-prefixed RLP-encoded hex string
blockNumber	string	Yes	Target block number as a hex string (e.g. "0x1234567")
minTimestamp	number	No	Minimum block timestamp (Unix seconds) for inclusion
maxTimestamp	number	No	Maximum block timestamp (Unix seconds) for inclusion
revertingTxHashes	string[]	No	Tx hashes allowed to revert without invalidating the bundle
droppingTxHashes	string[]	No	Tx hashes that, if already included on-chain, cause the bundle to be dropped rather than fail
replacementUuid	string	No	UUID string to enable bundle replacement (submit a new bundle with the same UUID to replace)
replacementNonce	number	No	Monotonically increasing nonce for replacement ordering. Auto-populated if omitted.
refundPercent	number	No	Percentage (0–100) of builder profit to refund to refundRecipient
refundRecipient	string	No	Address that receives the refund payment
refundTxHashes	string[]	No	Specific tx hashes whose execution profit is used for refund calculation
delayedRefund	boolean	No	If true, refund is sent in the next block instead of the same block
targetPools	string[]	No	Hint to the builder — list of DEX pool addresses this bundle interacts with

Request

{
  "jsonrpc": "2.0",
  "method": "eth_sendBundle",
  "params": [{
    "txs": [
      "0x02f8...",
      "0x02f9..."
    ],
    "blockNumber": "0x137f8a0",
    "revertingTxHashes": [],
    "replacementUuid": "550e8400-e29b-41d4-a716-446655440000"
  }],
  "id": 1
}

Response

{
  "jsonrpc": "2.0",
  "result": {
    "bundleHash": "0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890"
  },
  "id": 1
}

Field	Type	Description
bundleHash	string	0x-prefixed keccak256 hash identifying the bundle. Use with eureka_getBundleStats.

Bundle Replacement

To replace a previously submitted bundle, submit a new bundle with the same replacementUuid. The builder will discard the old bundle and process the new one. To cancel without submitting a replacement, use eth_cancelBundle.

Notes

• The bundle is only eligible for inclusion in the specified blockNumber. It is discarded after that block is built.

• All transactions in the bundle execute atomically — if any non-reverted tx fails, the entire bundle is excluded.

• Transactions listed in revertingTxHashes may revert without affecting bundle inclusion.

Examples