RPC docs

eth_sendRawTransaction

Sends a transaction to beaver. The transaction will stay private.

Also supported under the name: eth_sendPrivateRawTransaction (exact same RPC).

This RPC accepts a single argument: the hex-encoded, raw transaction.

eth_sendBundle

Sends a bundle to beaver. It will stay private.

This RPC accepts a dictionary of:

txs

List of hex-encoded, raw transactions. Can be empty for cancelling a bundle.

blockNumber

The block that this bundle will be valid for. 0 means it's valid for the next block (and only this one).

minTimestamp

Optional. If specified and >0, the bundle will only be valid if the block timestamp is greater or equal to minTimestamp.

maxTimestamp

Optional. If specified and >0, the bundle will only be valid if the block timestamp is smaller or equal to maxTimestamp.

revertingTxHashes

Optional. A list of transaction hashes contained in the bundle, that can be allowed to revert, or be removed from your bundle if it's deemed useful.

droppingTxHashes

Optional. A list of transaction hashes contained in the bundle, that can be allowed to be removed from your bundle if it's deemed useful (but not revert).

uuid

Optional. An UUID string, which allows you to update/cancel your bundles: if you specify an uuid and we already have a bundle with an identical one, we'll forget about the old bundle. So we can only have a single bundle with a certain uuid at all time (and we keep the most recent).

replacementUuid

Optional, deprecated, alias for uuid.

refundPercent

Optional. An integer between 1-99. How much of the total priority fee + coinbase payment you want to be refunded for. This will negatively impact your prioritization because this refund is gonna eat into your bundle payment. Example: if a bundle pays 0.2 ETH of priority fee plus 1 ETH to coinbase, a refundPercent set to 50 will result in a transaction being appended after the bundle, paying 0.59 ETH back to the EOA. This is assuming the payout tx will cost beaver 0.01 ETH in fees, which are deduced from the 0.6 ETH payout.

refundRecipient

Optional. You can specify an address that the funds from refundPercent will be sent to. If not specified, they will be sent to the from address of the first transaction.

refundTxHashes

Optional. The hash of the single transaction in the bundle that the refund will be based on. If it's empty, we'll use the last transaction. If there is more than one hash, the bundle will be rejected.

boost

Deprecated, can no longer be set to false. A boolean, defaults to true as of October 1, 2024. If set to true, will augment your bundle to bump the transactions total priority fee to increase inclusion and block position.

allowBuilderNetRefunds

A boolean, defaults to true since 1st May, 2025. If set to false, transactions may not be forwarded to BuilderNet for improved inclusion. Transactions forwarded to BuilderNet become eligible for refunds if builderNetRefundAddress is set.

builderNetRefundAddress

Optional. You can specify an address that will receive builderNet refunds in ETH when allowBuilderNetRefunds is not false. From 3rd November, 2025: must be set explicitly to be eligible for refunds.

Bundle cancellation: Say that you sent a bundle with uuid "10ba43b9c689ed0242b3". If you want to cancel it entirely, you can send a bundle with the same uuid, and an empty list of transactions.

Example of sending a bundle:

curl -X POST -H 'Content-Type: application/json' --data '{
    "id": 1,
    "jsonrpc": "2.0",
    "method": "eth_sendBundle",
    "params": [
        {
          "txs" : [
              "0x02f8b20181948449bdee618501dcd6500083016b93942dabcea55a12d73191aece59f508b191fb68adac80b844095ea7b300000000000000000000000054e44dbb92dba848ace27f44c0cb4268981ef1cc00000000000000000000000000000000000000000000000052616e065f6915ebc080a0c497b6e53d7cb78e68c37f6186c8bb9e1b8a55c3e22462163495979b25c2caafa052769811779f438b73159c4cc6a05a889da8c1a16e432c2e37e3415c9a0b9887"
          ],
          "blockNumber" : "0x1361bd3"
        }
    ]
}' https://rpc.beaverbuild.org/