DiceRandomHook

A trading tax hook. It changes its fee with the market, takes a tax on trades and burns tokens.

• Fee changes with the market

  Instead of a fixed fee, it picks the fee on every trade: higher when the price moves fast or drifts from its target, lower when things are calm.

  The code that does this (beforeSwap):

  function beforeSwap(address sender, PoolKey calldata key, SwapParams calldata params, bytes calldata)
      external
      onlyPoolManager
      returns (bytes4, BeforeSwapDelta, uint24)
  {
      if (params.amountSpecified >= 0) revert ExactOutputUnsupported();
      PoolId id = key.toId();
      PoolInfo storage p = _info(id);
  
      if (!params.zeroForOne) {
          // Sell: fixed policy, no roll. The platform fee is taken from the ETH output in afterSwap.
          (uint24 sf, int24 drop, bool armed) = _sellFee(id);
          emit SellPolicy(id, sf, drop, armed);
          return (IHooks.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, sf | LPFeeLibrary.OVERRIDE_FEE_FLAG);
      }
      // The hook's own buy-back-and-burn (BURN rolls) and the platform buyback: no dice or platform fee,
      // no roll, no launch cap. Platform money must never pay out a rebate or a CLOCK pot to whoever
      // triggered the swap (tx.origin).
      if (sender == address(this) || sender == _platformRecipient) {
          return (IHooks.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, BASE_FEE | LPFeeLibrary.OVERRIDE_FEE_FLAG);
      }
  
      uint256 amountIn = uint256(-params.amountSpecified);
      address buyer = _buyerOf(sender);
      RandomConfig storage c = _configs[id];
      if (block.timestamp < uint256(p.launchedAt) + c.guardWindow) {
          uint256 bought = _boughtInWindow[id][buyer] + amountIn;
          if (bought > c.guardMaxBuy) revert LaunchCapExceeded(bought, c.guardMaxBuy);
          _boughtInWindow[id][buyer] = bought;
      }
      // …

• Takes a tax on trades

  On top of the normal pool fee, it keeps part of each trade as a tax. Buys and sells can be taxed differently.

  The code that does this (beforeSwap):

  function beforeSwap(address sender, PoolKey calldata key, SwapParams calldata params, bytes calldata)
      external
      onlyPoolManager
      returns (bytes4, BeforeSwapDelta, uint24)
  {
      if (params.amountSpecified >= 0) revert ExactOutputUnsupported();
      PoolId id = key.toId();
      PoolInfo storage p = _info(id);
  
      if (!params.zeroForOne) {
          // Sell: fixed policy, no roll. The platform fee is taken from the ETH output in afterSwap.
          (uint24 sf, int24 drop, bool armed) = _sellFee(id);
          emit SellPolicy(id, sf, drop, armed);
          return (IHooks.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, sf | LPFeeLibrary.OVERRIDE_FEE_FLAG);
      }
      // The hook's own buy-back-and-burn (BURN rolls) and the platform buyback: no dice or platform fee,
      // no roll, no launch cap. Platform money must never pay out a rebate or a CLOCK pot to whoever
      // triggered the swap (tx.origin).
      if (sender == address(this) || sender == _platformRecipient) {
          return (IHooks.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, BASE_FEE | LPFeeLibrary.OVERRIDE_FEE_FLAG);
      }
  
      uint256 amountIn = uint256(-params.amountSpecified);
      address buyer = _buyerOf(sender);
      RandomConfig storage c = _configs[id];
      if (block.timestamp < uint256(p.launchedAt) + c.guardWindow) {
          uint256 bought = _boughtInWindow[id][buyer] + amountIn;
          if (bought > c.guardMaxBuy) revert LaunchCapExceeded(bought, c.guardMaxBuy);
          _boughtInWindow[id][buyer] = bought;
      }
      // …

• Burns tokens

  It destroys some tokens (or sends them to an address nobody controls), so there are fewer of them.

  The code that does this (unlockCallback):

  function unlockCallback(bytes calldata data) external onlyPoolManager returns (bytes memory) {
      (uint8 action, bytes memory inner) = abi.decode(data, (uint8, bytes));
      if (action == ACTION_REDEEM) {
          (Currency c, address to, uint256 amount) = abi.decode(inner, (Currency, address, uint256));
          poolManager().burn(address(this), c.toId(), amount);
          poolManager().take(c, to, amount);
          return "";
      }
      // FLOOR reinforcement and buy-back-and-burn live in the modules; run them on this storage.
      (bool ok, bytes memory ret) = module.delegatecall(abi.encodeWithSignature("unlockAction(uint8,bytes)", action, inner));
      if (!ok) {
          assembly ("memory-safe") {
              revert(add(ret, 32), mload(ret))
          }
      }
      return abi.decode(ret, (bytes));
  }

• Launch protection

  Around launch it limits trading, for example a max buy or wallet size or a cooldown, to stop bots grabbing the supply before real traders.

  The code that does this (beforeSwap):

  function beforeSwap(address sender, PoolKey calldata key, SwapParams calldata params, bytes calldata)
      external
      onlyPoolManager
      returns (bytes4, BeforeSwapDelta, uint24)
  {
      if (params.amountSpecified >= 0) revert ExactOutputUnsupported();
      PoolId id = key.toId();
      PoolInfo storage p = _info(id);
  
      if (!params.zeroForOne) {
          // Sell: fixed policy, no roll. The platform fee is taken from the ETH output in afterSwap.
          (uint24 sf, int24 drop, bool armed) = _sellFee(id);
          emit SellPolicy(id, sf, drop, armed);
          return (IHooks.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, sf | LPFeeLibrary.OVERRIDE_FEE_FLAG);
      }
      // The hook's own buy-back-and-burn (BURN rolls) and the platform buyback: no dice or platform fee,
      // no roll, no launch cap. Platform money must never pay out a rebate or a CLOCK pot to whoever
      // triggered the swap (tx.origin).
      if (sender == address(this) || sender == _platformRecipient) {
          return (IHooks.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, BASE_FEE | LPFeeLibrary.OVERRIDE_FEE_FLAG);
      }
  
      uint256 amountIn = uint256(-params.amountSpecified);
      address buyer = _buyerOf(sender);
      RandomConfig storage c = _configs[id];
      if (block.timestamp < uint256(p.launchedAt) + c.guardWindow) {
          uint256 bought = _boughtInWindow[id][buyer] + amountIn;
          if (bought > c.guardMaxBuy) revert LaunchCapExceeded(bought, c.guardMaxBuy);
          _boughtInWindow[id][buyer] = bought;
      }
      // …

• Rewards to claim

  It keeps track of rewards to be claimed later.

Who controls it: No admin functions: nobody can change its rules after deployment.

Based on the hook’s published code.