Add BuyPexfi ignition module and fix pool tick spacing

evm/modules/01_Market.ts

@@ -84,7 +84,7 @@ export default buildModule('Market', (m) => {
     pexfi,
     universalRouter,
     m.getParameter('weth_address'),
-    [zeroAddress, pexfi, 10000, 60, zeroAddress],
+    [zeroAddress, pexfi, 10000, 200, zeroAddress],
   ])
   m.call(Market, 'changeImplementationAddress', [bytes32('FeeCollector'), feeCollector], {
     id: 'regFeeCollector',
@@ -129,9 +129,9 @@ export default buildModule('Market', (m) => {
     id: 'collateralWhitelist',
   })
   m.call(CollateralWhitelist, 'addToWhitelist', [pexfiVault])
-  // With OOv3 defaults (50% burn), Minimum Bond = Final Fee * 2 = 200,000 tokens.
+  // With OOv3 defaults (50% burn), Minimum Bond = Final Fee * 2 = 200 tokens.
   // This ensures only the deployer can assert/dispute initially.
-  const initialFinalFee = 100_000n * 10n ** 18n
+  const initialFinalFee = 100n * 10n ** 18n
   m.call(Store, 'setFinalFee', [pexfiVault, { rawValue: initialFinalFee }])
 
   // Placeholder Oracle address — syncUmaParams requires it at deploy time.

evm/modules/03_BuyPexfi.ts

@@ -0,0 +1,23 @@
+import { buildModule } from '@nomicfoundation/hardhat-ignition/modules'
+import { parseEther } from 'viem'
+
+/**
+ * This module performs a buyback of PEXFI tokens from the Uniswap v4 pool.
+ * It uses a standalone action contract to perform the swap in a single transaction.
+ */
+export default buildModule('BuyPexfi', (m) => {
+  const amount = parseEther('0.0003')
+  const pexfi = m.getParameter('pexfi_address', '0xCCA91e36E5c15163C5258832C57774072Db257C5')
+  const universalRouter = m.getParameter('uniswapUniversalRouter')
+
+  // Deploy the action contract
+  const action = m.contract('PexfiBuybackAction')
+
+  // Execute the buyback
+  m.call(action, 'run', [universalRouter, pexfi], {
+    id: 'buybackPexfi',
+    value: amount,
+  })
+
+  return { action }
+})

evm/protocol/PexfiBuybackAction.sol

@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.34;
+
+import {IUniversalRouter} from "@uniswap/universal-router/contracts/interfaces/IUniversalRouter.sol";
+import {Commands} from "@uniswap/universal-router/contracts/libraries/Commands.sol";
+import {Currency} from "@uniswap/v4-core/src/types/Currency.sol";
+import {PoolKey} from "@uniswap/v4-core/src/types/PoolKey.sol";
+import {IHooks} from "@uniswap/v4-core/src/interfaces/IHooks.sol";
+import {Actions} from "@uniswap/v4-periphery/src/libraries/Actions.sol";
+import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+
+/**
+ * @title PexfiBuybackAction
+ * @notice Standalone contract to buy PEXFI from Uniswap v4 pool in a single transaction.
+ */
+contract PexfiBuybackAction {
+    function run(address router, address pexfi) external payable {
+        require(msg.value > 0, "No ETH sent");
+
+        PoolKey memory poolKey = PoolKey({
+            currency0: Currency.wrap(address(0)),
+            currency1: Currency.wrap(pexfi),
+            fee: 10000,
+            tickSpacing: 200,
+            hooks: IHooks(address(0))
+        });
+
+        bytes memory v4Actions = abi.encodePacked(
+            uint8(Actions.SWAP_EXACT_IN_SINGLE),
+            uint8(Actions.SETTLE),
+            uint8(Actions.TAKE_ALL)
+        );
+
+        bytes[] memory v4Inputs = new bytes[](3);
+
+        // 1. Swap ETH for PEXFI
+        v4Inputs[0] = abi.encode(
+            poolKey,
+            true, // zeroForOne (ETH is currency0)
+            uint128(msg.value),
+            uint128(0), // amountOutMinimum
+            "" // hookData
+        );
+
+        // 2. Settle ETH (pay from the ETH sent to this contract)
+        v4Inputs[1] = abi.encode(
+            Currency.wrap(address(0)),
+            msg.value,
+            false // payerIsUser = false (take from this contract)
+        );
+
+        // 3. Take PEXFI (send to this contract)
+        v4Inputs[2] = abi.encode(
+            Currency.wrap(pexfi),
+            0 // minAmount
+        );
+
+        bytes memory commands = abi.encodePacked(bytes1(uint8(Commands.V4_SWAP)));
+        bytes[] memory inputs = new bytes[](1);
+        inputs[0] = abi.encode(v4Actions, v4Inputs);
+
+        // Execute the swap on Universal Router
+        IUniversalRouter(router).execute{value: msg.value}(commands, inputs, block.timestamp + 600);
+
+        // Send bought PEXFI tokens back to the caller
+        uint256 pexfiBal = IERC20(pexfi).balanceOf(address(this));
+        if (pexfiBal > 0) {
+            bool success = IERC20(pexfi).transfer(msg.sender, pexfiBal);
+            require(success, "Transfer failed");
+        }
+
+        // Send back any remaining ETH
+        if (address(this).balance > 0) {
+            (bool success, ) = msg.sender.call{value: address(this).balance}("");
+            require(success, "ETH refund failed");
+        }
+    }
+
+    receive() external payable {}
+}

tests/hardhat/ignition/03_BuyPexfi.test.ts

@@ -0,0 +1,22 @@
+import { describe, test } from 'node:test'
+import * as assert from 'node:assert'
+import BuyPexfiModule from '@evm/modules/03_BuyPexfi.ts'
+import deploy from './01_Market.test.ts'
+
+describe('BuyPexfi Module', () => {
+  test('should execute buyback successfully', async () => {
+    const { ignition, universalRouter, pexfi } = await deploy()
+
+    const parameters = {
+      BuyPexfi: {
+        pexfi_address: pexfi.address,
+        uniswapUniversalRouter: universalRouter.address,
+      },
+    }
+
+    // Deploy and run the BuyPexfi module
+    const { action } = await ignition.deploy(BuyPexfiModule, { parameters })
+
+    assert.ok(action.address, 'PexfiBuybackAction should be deployed')
+  })
+})