Private Transactions

The blxr_private_tx endpoint allows users to send a single transaction that is added directly to the blocks generated by block builders.

Private txs are automatically enrolled in the BackRunMe service and will pay back searchers a portion of the profit. The endpoint returns a transaction hash.

This service is available via both the Cloud API and Gateway API.

Submission Endpoint

• Method: blxr_private_tx

• Endpoint: api.blxrbdn.com (Cloud API)

• Gateway API Endpoint: 127.0.0.1:28333/ws (assumes WebSocket port 28333)

• Request type: HTTPS,WSS

Parameters

Parameter	Description
transaction	[Mandatory] Raw transaction bytes without 0x prefix.
timeout	[Optional] An integer value that represents the time, in seconds, needed to wait for a Private Transaction to be included in a block. If omitted, it defaults to 0. If timeout is not 0 and the transaction is not mined after the timeout value, it will be sent publicly. If the timeout is 0, no public transaction will be sent.
mev_builders	[Optional, default: all builder] A dictionary of MEV builders that should receive the private transaction. Please provide empty string as signature for each builder. Possible MEV builders are: flashbots: flashbots builder beaverbuild: beaverbuild.org rsync-builder : rsync-builder.xyz all: all builders Traders can refer to List of External Builders page for a full list.
node_validation	[Optional, default: false] Transaction would be validated by a blockchain node, and Cloud-API returns an error message (e.g. "invalid sender" or "nonce too low") in case the raw transaction byte fails validation check.
priority_fee_refund	[Optional, default: False] A boolean flag indicating if the bundle should be sent just to a single block builder who is participating in the priority fee refund program. Please refer to Priority Fee Refund for details of the priority fee refund program.
refund_recipient	[Optional] A string representing the wallet address to receive refund when priority_fee_refund flag is enabled.

Example

HTTPS - Cloud API

curl https://api.blxrbdn.com \
    --insecure \
    -X POST \
    -H "Content-Type: application/json" \
    -H "Authorization: <YOUR-AUTHORIZATION-HEADER>" \
    -d '{
         "id": "1", 
         "method": "blxr_private_tx", 
         "params": {
            "transaction": "f86b0184...e0b58219",
            "mev_builders": {
                "flashbots": "",
                "beaverbuild": "",
                "all": ""
	     }
          }
        }'

wscat - Cloud API

Response

Cloud-API

{
    "jsonrpc": "2.0", 
    "id": "1", 
    "result": "0xffd59870844e5...bfa54a69"        
}