Auction Transaction Feed

Update:

A filter was added to the logs and stateDiffs. See Content of Logs and StateDiffs

newPendingAuctions: require 48 SP points to subscribe

newPendingAuctionsWithState: require 480 SP points to subscribe

Introduction

Introducing Auction Feed, a WebSocket-RPC based subscription data feed that delivers transaction-related data from the 48Club RPC service. Unlike traditional pending transaction subscriptions, Auction Feed focuses specifically on backrun opportunities, providing only the target hashes of these opportunities and the relevant logs and EVM state changes after simulation.

The tracked targets may be individual transactions or bundles, but this distinction is unimportant, as the searcher only needs to assess whether a backrun opportunity exists based on the logs or state changes triggered by the target. When you submit a SendBundle with a target hash, the server automatically prepends the target transaction to the front of your bundle.

How to Subscribe

Subscribing to Auction Feed push notifications requires no complex third-party packages. You can achieve this using go-ethereum. Simply connect to our WebSocket RPC service and subscribe to either the newPendingAuctions or newPendingAuctionsWithState event, depending on the data you need.

How to SendBundle

To submit a bundle that includes a backrun opportunity, use the eth_sendBundle method with the backrunTarget parameter configured.

• Please note that if the target’s gas price is below 1 gwei, it will not be considered a public pool transaction, so you must include it in your bundle’s average gas price calculation to meet the 1 gwei requirement. However, if the target’s gas price exceeds 1 gwei, you should not factor it into your bundle’s average gas price, as it is treated as a public pool transaction.

Data Format

Due to the high frequency of updates, we use gzip compression on the raw data to minimize transmission size and enhance delivery speed. This ensures efficient handling of the Auction Feed’s frequent push notifications.

Example code for decompressing gzip data

Subscription to newAuctions

Example code here

This provides essential data to check what a transaction has triggered. It is sufficient for arbitrage strategies, such as those on Uniswap v2 liquidity pools, without requiring simulation.

Field	Format	Description
hash	string (0x hash)	The auction target ID
extra_gas_fee	uint64	An additional total gas fee needs to be burned in your bundle to meet the 1 Gwei requirement for including this transaction.
logs	[] logData	The logs produced in target simulation
exp: logData.address	string (0x address)
exp: logData.topics	[] string (0x hash)
exp: logData.data	string (0x data)

• Note: if the target gas_price is below 1 gwei, you should included it into your bundle's average GasPrice calculation. Check here.

Subscription to newAuctionsWithStates

Example code here

This provides advanced data for simulation-based strategies. You can create a state from the current moment and apply the state changes provided in the data. Then, begin your simulation as though it were happening in real time on the target transaction.

• You have to sign current unix timestamp string by your 48SoulPoint EOA Example code here
• How to apply state changes on current StateDB Example code here
• newAuctionsWithStates has all data in newAuctions, plus states below

Field	Format	Description
`states`	map[str(1)]map[str(2)]str(3)	The state key/value changes on all state objects.
exp: states.str(1)	string (0x address)	The address of changed state object
exp: states.str(2)	string (0x hash)	changed Key in a changed state object
exp: states.str(3)	string (0x hash)	changed Value of Key

Content of Logs and StateDiffs

The broadcast logs of a transaction are filtered (see the topic list below), and only topics related to backrunning will be broadcasted, along with the stateDiffs corresponding to this Log.Address.

If you believe we should include additional topics for the backrunning auction, please let us know at @infra_48club.

Signature	topics[0]
Sync(uint256, uint256)	0xcf2aa50876cdfbb541206f89af0ee78d44a2abf8d328e37fa4917f982149848a
Sync(uint112, uint112)	0x1c411e9a96e071241c2f21f7726b17ae89e3cab4c78be50e062b03a9fffbbad1
Sync(uint112 reserve0, uint112 reserve1, uint256 totalSupply)	0x17be3acebd510daa18778e1ee1fbaf88237b124dc0803c3be2fd4f99f3e69d33
Sync(uint256 vReserve0, uint256 vReserve1, uint256 reserve0, uint256 reserve1)	0x2f9d55abfefdfd4c3a83e00a1b419b3c2fe4b83100c559f0e2213e57f6e0bba9
Swap(address,address,int256,int256,uint160,uint128,int24)	0xc42079f94a6350d7e6235f29174924f928cc2ac818eb64fed8004e115fbcca67
Burn(address,int24,int24,uint128,uint256,uint256)	0x0c396cd989a39f4459b5fa1aed6a9a8dcdbc45908acfd67e028cd568da98982c
Mint(address,address,int24,int24,uint128,uint256,uint256)	0x7a53080ba414158be7ec69b987b5fb7d07dee101fe85488f0853ae16239d0bde
Swap(address,uint256,uint256,uint256,uint256,address)	0xd78ad95fa46c994b6551d0da85fc275fe613ce37657fb8d5e3d130840159d822
Swap(index_topic_1 address sender, index_topic_2 address recipient, int256 amount0, int256 amount1, uint160 sqrtPriceX96, uint128 liquidity, int24 tick, uint128 protocolFeesToken0, uint128 protocolFeesToken1)	0x19b47279256b2a23a1665c810c8d55a1758940ee09377d4f8d26497a3577dc83
Swap(index_topic_1 address sender, uint256 amount0In, uint256 amount1In, uint256 amount0Out, uint256 amount1Out, index_topic_2 address to, uint256 feeInPrecision)	0x606ecd02b3e3b4778f8e97b2e03351de14224efaa5fa64e62200afc9395c2499
Swap(index_topic_1 bytes32 id, index_topic_2 address sender, int128 amount0, int128 amount1, uint160 sqrtPriceX96, uint128 liquidity, int24 tick, uint24 fee)	0x40e9cecb9f5f1f1c5b9c97dec2917b7ee92e57ba5563708daca94dd84ad7112f
ModifyLiquidity(index_topic_1 bytes32 id, index_topic_2 address sender, int24 tickLower, int24 tickUpper, int256 liquidityDelta, bytes32 salt)	0xf208f4912782fd25c7f114ca3723a2d5dd6f3bcc3ac8db5af63baa85f711d5ec
fourmeme Create	0x396d5e902b675b032348d3d2e9517ee8f0c4a926603fbc075d3d282ff00cad20