FoundationHookV2

Foundation runs one token's pool with a fee in the paired coin and a set of add-on modules fixed at launch. The fee is shared between the platform, the pool creator and the modules, which each get a set budget to use.

• Fee in the paired coin

  Each trade pays a platform fee plus a pool creator fee, taken from the paired coin before or after the swap.

  The code that does this (_beforeSwap):

  function _beforeSwap(address sender, PoolKey calldata key, SwapParams calldata params, bytes calldata)
      internal
      override
      returns (bytes4, BeforeSwapDelta, uint24)
  {
      // A standalone action may route a fee-paying swap through an external router. A swap callback
      // may never start another swap. Phase 3 restores the existing action only after full settlement.
      if (_phase != 0 && _phase != 2) revert ReentrantOperation();
      if (PoolId.unwrap(key.toId()) != poolId) revert InvalidSwap();
      _phase = _phase == 2 ? 3 : 1;
      uint256 specified = _specifiedAmount(params.amountSpecified);
      bool buy = params.zeroForOne == (quote < token);
      T.SwapContext memory context_ =
          T.SwapContext(poolId, sender, buy, params.amountSpecified < 0, specified, 0, 0, 0);
      _dispatch(T.BEFORE_SWAP, context_);
      if (buy != (params.amountSpecified < 0)) {
          return (IHooks.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, 0);
      }
      uint256 gross = specified;
      F.Result memory result;
      if (buy) result = F.quoteGross(gross, _creatorFeeBps(buy), feeCarry[buy]);
      else (gross, result) = F.quoteNet(specified, _creatorFeeBps(buy), feeCarry[buy]);
      // Carry is committed only after the actual full fill is validated in afterSwap.
      return (IHooks.beforeSwap.selector, toBeforeSwapDelta(int128(int256(_checkedFee(gross, result))), 0), 0);
  }

• Modules chosen at launch

  The pool is set up with a list of modules and their share of the token creator fees. The list cannot change after launch.

  The code that does this (_configureModules):

  function _configureModules(T.ModuleSelection[] memory selections) private {
      if (selections.length > T.MAX_MODULES) revert InvalidConfiguration();
      address[] memory instances = new address[](selections.length);
      uint16[] memory shares = new uint16[](selections.length);
      uint256 totalSwapGas;
      for (uint256 i; i < selections.length; ++i) {
          T.ModuleSelection memory selection = selections[i];
          if (
              selection.factory.code.length == 0 || selection.factory.codehash != selection.factoryCodeHash
                  || selection.configuration.length > 16_384
          ) revert InvalidConfiguration();
          T.ModuleContext memory context_ =
              T.ModuleContext(address(this), token, quote, creator, address(ledger), poolId);
          address instance =
              IFoundationModuleFactoryV1(selection.factory).createModule(context_, selection.configuration);
          if (
              instance.code.length == 0 || instance.codehash != selection.moduleCodeHash
                  || instance == address(poolManager) || instance == address(ledger) || instance == initializer
          ) {
              revert InvalidConfiguration();
          }
          IFoundationModuleV1 module = IFoundationModuleV1(instance);
          T.Descriptor memory d = module.descriptor();
          bytes32 configHash = keccak256(selection.configuration);
          if (
              keccak256(abi.encode(module.context())) != keccak256(abi.encode(context_))
                  || module.configurationHash() != configHash || keccak256(abi.encode(d)) != selection.descriptorHash
                  || d.abiVersion != 1 || d.moduleId == 0 || d.phases == 0 || d.phases > 7 || d.resources > 1
                  || d.beforeGas > 300_000 || d.afterGas > 300_000 || d.actionGas > 2_000_000
                  || ((d.phases & T.BEFORE_SWAP) != 0 && d.beforeGas < 10_000)
      // …

• Modules run on trades

  Modules are called during each trade with a gas limit. If one fails, the trade still goes through.

  The code that does this (_dispatch):

  function _dispatch(uint8 phase, T.SwapContext memory context_) private {
      for (uint256 i; i < _modules.length; ++i) {
          Module storage m = _modules[i];
          if ((m.descriptor.phases & phase) == 0) continue;
          bool before_ = phase == T.BEFORE_SWAP;
          bytes4 selector =
              before_ ? IFoundationModuleV1.onBeforeSwap.selector : IFoundationModuleV1.onAfterSwap.selector;
          bool ok = _call(
              m,
              abi.encodeWithSelector(selector, context_),
              before_ ? m.descriptor.beforeGas : m.descriptor.afterGas,
              selector
          );
          if (!ok) {
              if (before_ || !m.descriptor.failOpenAfter) revert ModuleFailure(i, phase);
              emit ModuleCallbackFailed(i, phase);
          }
      }
  }

• Fees held in a ledger

  Fees go to a ledger contract where the platform, the pool creator and each module claim their part.

  The code that does this (claimPlatform):

  function claimPlatform() external nonReentrant returns (uint256 amount) {
      amount = _bounded(platformReceived - platformClaimed);
      platformClaimed += amount;
      _pay(T.PLATFORM_RECIPIENT, amount);
      emit QuoteClaimed(T.PLATFORM_RECIPIENT, 0, amount);
  }

Who controls it: Nobody can change the fee or the modules after launch. The code cannot be upgraded.

Based on the hook’s published code.