Searcher

Introduction

Searchers can subscribe to transactions from the Private Mempool to execute backrun strategies, and then send bid to BlockRazor RPC to win the backrun auction.

Additionally, searchers can skip bundle subscriptions and directly send bundles to BlockRazor RPC. With the network acceleration service of the high-performance network, BlockRazor RPC can forward bundles to builders with minimal latency, eliminating the need to repeatedly connect to builder interfaces.

RPC Endpoint

{% hint style="info" %} Please keep the domain for subscribing to the bundle consistent with the domain for sending the bundle. For example, if subscribing to https://jp-ethscutum.blockrazor.xyz/stream, then send the bundle to https://jp-ethscutum.blockrazor.xyz {% endhint %}

Region	Endpoint
Tokyo	https://jp-ethscutum.blockrazor.xyz
New York	https://us-ethscutum.blockrazor.xyz

eth_sendBid

{% hint style="info" %} To protect private transactions, eth_sendBid is restricted to designated Searchers. Please contact us if you need to send a bid. {% endhint %}

Request Parameter

Parameter	Mandatory	Format	Example	Remark
txs	Mandatory	[]string	["tx_hash", "rawTxHex"]	tx_hash refers to the originator transaction in the Private Mempool, while rawTxHex is the backrun transaction being constructed. If the backrun target is a bundle, please fill in all tx_hash values from the bundle.
blockNumber	Optional	hex string	"0x102286B"	A hex-encoded block number indicating the latest valid block for the bundle. The default value is the current block number + 100.

Bid mechanism

BlockRazor will replace the tx_hash in the Bid with rawTxHex, and after adding refundPercent and refundRecipient, immediately forward it to the Builder for block inclusion.

From the Builder's perspective, the Bid's value is determined by the backrun transaction’s priority fee + coinbase.transfer(). Since the refundPercent for the same originator transaction remains consistent, the Bid with the highest total value will be successfully included.

Request Example

Backrun Originator Transaction

curl https://eth.blockrazor.xyz \
  -X POST \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <token>" \
  --data '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "eth_sendBid",
    "params": [
      {
        "txs": [
          "0x3a3c086bad1e765076986814939d2be70399e85ff75e4da8ec730aaf6ce3fea1",
          "0x02f86d0182149c808411e1a300830484e294fef10de0823f58df4f5f24856ab4274ededa6a5c8084c179306cc001a075d1f8fea39352c2da065aeef85be4b24789953f57a62ca7ad29b45bfc1e362aa043de44543083d0dafb80eaedd5764d6ef03336ff028ef02f238bccd5dfa9ece9"
        ],
        "blockNumber": "0x102286B"
      }
    ]
  }'

Backrun Originator Bundle

curl https://eth.blockrazor.xyz \
  -X POST \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <token>" \
  --data '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "eth_sendBid",
    "params": [
      {
        "txs": [
          "0x3a3c086bad1e765076986814939d2be70399e85ff75e4da8ec730aaf6ce3fea1",
          "0x47816242f30167d1525a98801355f49370fc83049cb070d5d3ae9fd6c83d2d9d",
          "0x02f86d0182149c808411e1a300830484e294fef10de0823f58df4f5f24856ab4274ededa6a5c8084c179306cc001a075d1f8fea39352c2da065aeef85be4b24789953f57a62ca7ad29b45bfc1e362aa043de44543083d0dafb80eaedd5764d6ef03336ff028ef02f238bccd5dfa9ece9"
        ],
        "blockNumber": "0x102286B"
      }
    ]
  }'

eth_sendBundle

Searchers can also act as project builders to send raw bundles. For details, please refer to Project Builder.