Akita Builder — MEV Block Builder

Send Bundles

Submit transaction bundles to Akita Builder for inclusion in the next block. We build blocks and submit bids to all major MEV-Boost relays on Ethereum mainnet.

POST https://akitabuilder.com

eth_sendBundle

Submit a bundle of signed transactions targeting a specific block number. Transactions execute atomically and in order.

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "eth_sendBundle",
  "params": [{
    "txs": [
      "0x02f8..."   // signed transactions
    ],
    "blockNumber": "0x..."   // target block (hex)
  }]
}

Parameters

Field	Type	Description
`txs`	Array	Signed, RLP-encoded transactions as hex strings
`blockNumber`	String	Target block number in hex
`minTimestamp`	Number	Minimum block timestamp (optional)
`maxTimestamp`	Number	Maximum block timestamp (optional)
`revertingTxHashes`	Array	Tx hashes allowed to revert (optional)
`replacementUuid`	String	UUID for bundle replacement (optional)

Response

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "bundleHash": "0xabc123..."
  }
}

Examples

curl

curl -X POST https://akitabuilder.com \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "eth_sendBundle",
    "params": [{
      "txs": ["0x02f870..."],
      "blockNumber": "0x1234567"
    }]
  }'

Python (web3 / requests)

import requests

resp = requests.post("https://akitabuilder.com", json={
    "jsonrpc": "2.0",
    "id": 1,
    "method": "eth_sendBundle",
    "params": [{
        "txs": [signed_tx.rawTransaction.hex()],
        "blockNumber": hex(target_block),
    }]
})
print(resp.json())

ethers.js

const resp = await fetch("https://akitabuilder.com", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    jsonrpc: "2.0",
    id: 1,
    method: "eth_sendBundle",
    params: [{
      txs: [signedTx],
      blockNumber: `0x${targetBlock.toString(16)}`
    }]
  })
});
const data = await resp.json();

Details

How it works

Akita Builder receives your bundles, simulates them, and builds optimized blocks that include profitable bundles alongside public mempool transactions. Blocks are submitted as bids to MEV-Boost relays, where proposers select the highest-value block.

Relays

We submit to all major relays for maximum inclusion probability:

Relay	Type
Flashbots	Permissionless
Ultrasound	Permissionless
Aestus	Permissionless
Titan	Permissionless
Agnostic	Permissionless

Tip: Submit your bundle for multiple consecutive block numbers to maximize the chance of inclusion. The target block might be missed if another builder wins the slot.

Bundle Pricing

Bundles are prioritized by the effective gas price they pay. Higher tips = higher priority in block construction. Make sure your bundle's priority fee is competitive.

Rate Limits

Currently no rate limits. Be reasonable.