AntiSnipeRamp

How it works

The first block of a new pool is the most valuable block it will ever have. A bot that buys in it and sells an hour later takes the entire launch premium, and everyone who arrives through the front door pays for it. The usual answers are a whitelist, which is a promise rather than a mechanism, or a bonding curve that hands the premium to the deployer, which moves the extraction rather than removing it.

This hook makes the first block expensive to trade in and lets that expense decay: fee(t) = startFee - (startFee - endFee) * min(t, rampSeconds) / rampSeconds A sniper in the first second pays `startFee`, which can be set high enough that the trade is not worth making. A buyer twenty minutes later pays close to `endFee`. Because the fee is an LP fee, the premium the early trader surrenders is paid to the people who put the liquidity up, not to whoever deployed the token.

There is no address in this contract that can receive anything. A second lever handles the case where the fee alone is not enough. While the ramp is running, a single swap may not exceed `maxSwapDuringRamp` units of the specified currency.

This is a size cap, not an identity check, and it is deliberately not per-address: a hook sees the router that called the `PoolManager`, not the person behind it, so any per-address limit is a limit on routers and is defeated by a fresh key. Capping size is enforceable against everyone equally, including the deployer. Set it to zero to disable it.

Prior art: liquidity bootstrapping pools ramp the *price* down and were built for price discovery; several launchpad hooks charge a launch fee and route it to a creator or a protocol treasury. Ramping the *fee* down while directing the proceeds to liquidity is a different mechanism with a different beneficiary, and it composes with any curve rather than replacing it.

Using it

Uniswap v4 removed hookData from initialize, so per-pool parameters arrive out of band. Fix them for a pool key whose pool does not exist yet, then initialize. Nobody can change them afterwards, including you.

hook.configure(
    key,
    AntiSnipeRampHook.Config({
        startFee: /* uint24 */ 0,
        endFee: /* uint24 */ 0,
        rampSeconds: /* uint32 */ 0,
        maxSwapDuringRamp: /* uint128 */ 0
    })
);

poolManager.initialize(key, startingSqrtPriceX96);

The pool's fee field must be LPFeeLibrary.DYNAMIC_FEE_FLAG. The hook rejects a pool initialized without it, which is the most common integration failure.

Parameters

From TypeScript

npm i @hookforge/sdk

import {getHook, hookAddress, poolKeyFor} from "@hookforge/sdk";

const hook = getHook("anti-snipe-ramp");
const key  = poolKeyFor({
  hook: hookAddress("anti-snipe-ramp", 8453),   // Base
  currencyA: USDC, currencyB: WETH,
  tickSpacing: 60, dynamicFee: true,
});

What it reverts with

The callbacks it claims

Uniswap v4 reads a hook's permissions from the low fourteen bits of its own address, which is why deploying one means mining a CREATE2 salt. This hook claims 2, so every deployment of it has an address ending in 0x1080.

• beforeInitialize
• afterInitialize
• beforeAddLiquidity
• afterAddLiquidity
• beforeRemoveLiquidity
• afterRemoveLiquidity
• beforeSwap
• afterSwap
• beforeDonate
• afterDonate
• beforeSwapReturnsDelta
• afterSwapReturnsDelta
• afterAddLiquidityReturnsDelta
• afterRemoveLiquidityReturnsDelta

It says what it is, on-chain

Nothing about a hook's address tells an indexer, a wallet, a router or an agent what the pool does, which is why hook discovery today is a curated list. This hook answers for itself, in one eth_call, with no registry in the loop.

cast call $HOOK "hookName()(string)"    # AntiSnipeRamp
cast call $HOOK "specURI()(string)"     # https://anti-snipe-ramp.pages.dev/hook.json
cast call $HOOK "hookTags()(string[])"  # launch, anti-snipe, dynamic-fee, no-admin

Build, test and deploy

git clone --recurse-submodules https://github.com/nirholas/anti-snipe-ramp
cd anti-snipe-ramp
forge build && forge test

# Dry run: mines the salt, prints the address, sends nothing.
forge script script/Deploy.s.sol --rpc-url $RPC_URL

# For real.
forge script script/Deploy.s.sol --rpc-url $RPC_URL --broadcast --verify