kdb+/q for EVM

What is kdb+/q?, see kx.com

Overview

kdb+ adapted for usage on Ethereum/EVM Chains

This code is no longer in usage at Manifold Finance, which is why we have open sourced it.

Setup

1. You will need a license for kdb+ to use this, here is the install instructions via code.kx.com

2. Get the 64bit License via the On-Demand Personal exemption

Required Libraries

These libraries are required

https://github.com/manifoldfinance/qBigInt

https://github.com/manifoldfinance/qQuarticRoots

https://github.com/manifoldfinance/qAbiEncode

Example: Aave

see /aave dir

Will start 4 processes.

q realtime db for user balances.
subscribe to all lender events to update db balances.
query snapshot of every user balance (will take a long time to complete but liquidations can still occur in the background).
scan for unstable health and try to liquidate (prompt will appear for unlocking your accounts).
logs folder will hold log info.

To view live user balances and health: http://localhost:5010.

Utils

Jupyter Notebook for Sushiswap/Uniswap Liquidity and Market Depth

Install

From https://code.kx.com/q4m3/14_Introduction_to_Kdb+/1481-the-environment-variables, set QHOME to the location of q.k. To pass in a license, invoke q with QLIC set to the directory in which kc.lic is located. Other .q (or .k) files are loaded with \l path/to/file. .so files are loaded by defining their name/path when defining the function:

Flashbots Overview

https://docs.flashbots.net/flashbots-auction/overview

Notes on the current state of flashbots docs with relevance to assumptions of bundle process.

Anatomy of a bundle

const blockNumber = await provider.getBlockNumber()
const minTimestamp = (await provider.getBlock(blockNumber)).timestamp
const maxTimestamp = minTimestamp + 120
const signedBundle = flashbotsProvider.signBundle(
    [
      {
        signedTransaction: SIGNED_ORACLE_UPDATE_FROM_PENDING_POOL // serialized signed transaction hex
      },
      {
        signer: wallet, // ethers signer
        transaction: transaction // ethers populated transaction object
      }
    ])
const bundleReceipt = await flashbotsProvider.sendRawBundle(
    signedBundle, // bundle we signed above
    targetBlockNumber, // block number at which this bundle is valid
    {
      minTimestamp, // optional minimum timestamp at which this bundle is valid (inclusive)
      maxTimestamp, // optional maximum timestamp at which this bundle is valid (inclusive)
      revertingTxHashes: [tx1, tx2] // optional list of transaction hashes allowed to revert. Without specifying here, any revert invalidates the entire bundle.
    }
  )
)

Miner reward through coinbase.transfer()

https://docs.flashbots.net/flashbots-auction/searchers/advanced/coinbase-payment

To include as last action of smart contract

block.coinbase.transfer(AMOUNT_TO_TRANSFER)

Edge case to deal with sending to a miner contract

block.coinbase.call{value: _ethAmountToCoinbase}(new bytes(0));

subject to reentrancy attacks

Bundle pricing

https://docs.flashbots.net/flashbots-auction/searchers/advanced/bundle-pricing

Conflicting bundles received by flashbots are ordered by the following formula:

Eligibility

https://docs.flashbots.net/flashbots-auction/miners/mev-geth-spec/v04

Bundles must have a target blockNumber and a priorityFeePerGas >= 1 Gwei.

Reverting txs

https://docs.flashbots.net/flashbots-auction/miners/mev-geth-spec/v04

"When constructing a block the node should reject any bundle or megabundle that has a reverting transaction unless its hash is included in the RevertingTxHashes list of the bundle"

Debugging

https://docs-staging.flashbots.net/flashbots-auction/searchers/advanced/troubleshooting

1. Transaction failure (ANY within the bundle)
2. Incentives (gas price/coinbase transfers) not high enough to offset value of block space

Simulate bundle:

  const signedTransactions = await flashbotsProvider.signBundle(transactionBundle)
  const simulation = await flashbotsProvider.simulate(signedTransactions, targetBlockNumber, targetBlockNumber + 1)
  console.log(JSON.stringify(simulation, null, 2))

3. Competitors paying more

Get conflicting bundles for a prior block:

const signedTransactions = await flashbotsProvider.signBundle(transactionBundle)
console.log(await flashbotsProvider.getConflictingBundle(
      signedTransactions,
      13140328 // blockNumber
  ))

4. Bundle received too late to appear in target block

Get submission time data and compare to block time:

console.log(
  await flashbotsProvider.getBundleStats("0x123456789abcdef123456789abcdef123456789abcdef123456789abcdef1234", 13509887)
  )

License

This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.