MegaEth

README.md

@@ -127,7 +127,7 @@ your integration.
   hardfork (Ethereum mainnet, Ethereum Sepolia testnet, Polygon, Base, Optimism,
   Arbitrum, Blast, Bnb, Mode, World Chain, Gnosis, Fantom Sonic, Ink, Monad
   testnet, Avalanche, Unichain, Berachain, Scroll, HyperEvm, Katana, Plasma,
-  Monad mainnet, Abstract, Linea)
+  Monad mainnet, Abstract, Linea, MegaEth)
 * `0x0000000000005E88410CcDFaDe4a5EfaE4b49562` on chains supporting the Shanghai
   hardfork (Mantle, Taiko)
 
@@ -1408,7 +1408,12 @@ Zeroth, verify the configuration for your chain in
 [`chain_config.json`](chain_config.json),
 [`api_secrets.json.template`](api_secrets.json.template), and
 [`script/SafeConfig.sol`](script/SafeConfig.sol). Add the new chain to the list
-of `AllowanceHolder` addresses at the top of this file.
+of `AllowanceHolder` addresses at the top of this file. Pay attention to the
+`extraFlags` and `extraScriptFlags` fields. `extraFlags` should be `--legacy` on
+L2s that bill the DA fee directly in the native asset (e.g. OP stack
+rollups). `extraScriptFlags` should have `--isolate` on chains that aren't
+EraVM. `extraScriptFlags` should have `--skip-simulation` on chains with weird
+gas rules (i.e. Arbitrum, Mantle, Monad, MegaEth).
 
 First, you need somebody to give you a copy of `secrets.json`. If you don't have
 this, give up. Install [`scrypt`](https://github.com/Tarsnap/scrypt) and use it

api_secrets.json.template

@@ -102,5 +102,9 @@
   "abstract": {
     "etherscanKey": "",
     "rpcUrl": ""
+  },
+  "megaeth": {
+    "rpcUrl": "",
+    "blockscoutApi": ""
   }
 }

chain_config.json

@@ -176,7 +176,7 @@
     "isCancun": true,
     "isEraVm": false,
     "extraFlags": "--legacy",
-    "extraScriptFlags": "--isolate",
+    "extraScriptFlags": "--isolate --skip-simulation",
     "gasMultiplierPercent": 300,
     "minGasPriceGwei": 1,
     "wnative": "0x82aF49447D8a07e3bd95BD0d56f35241523fBab1",
@@ -379,7 +379,7 @@
     "isCancun": false,
     "isEraVm": false,
     "extraFlags": "--legacy",
-    "extraScriptFlags": "--isolate",
+    "extraScriptFlags": "--isolate --skip-simulation",
     "gasMultiplierPercent": 200,
     "minGasPriceGwei": 1,
     "wnative": "0x78c1b0C915c4FAA5FffA6CAbf0219DA63d7f4cb8",
@@ -572,7 +572,8 @@
       "forwardingMultiCall": "0x00000000000000CF9E3c5A26621af382fA17f24f",
       "crossChainFactory": "0x00000000000000304861c3aDfb80dd5ebeC96325"
     },
-    "etherscanApi": "https://api.etherscan.io/v2/api?chainid=146"
+    "etherscanApi": "https://api.etherscan.io/v2/api?chainid=146",
+    "sourcifyApi": "https://sourcify.dev/server/"
   },
   "ink": {
     "chainId": 57073,
@@ -816,7 +817,7 @@
     "isCancun": true,
     "isEraVm": false,
     "extraFlags": "",
-    "extraScriptFlags": "--isolate",
+    "extraScriptFlags": "--isolate --skip-simulation",
     "gasMultiplierPercent": 110,
     "minGasPriceGwei": 52,
     "safe": {
@@ -906,5 +907,25 @@
       "pause": "0x1CeC01DC0fFEE5eB5aF47DbEc1809F2A7c601C30"
     },
     "etherscanApi": "https://api.etherscan.io/v2/api?chainid=2741"
+  },
+  "megaeth": {
+    "chainId": 4326,
+    "displayName": "MegaEth",
+    "wnative": "0x4200000000000000000000000000000000000006",
+    "isShanghai": true,
+    "isCancun": true,
+    "isEraVm": false,
+    "extraFlags": "",
+    "extraScriptFlags": "--isolate --skip-simulation",
+    "gasMultiplierPercent": 200,
+    "minGasPriceGwei": 1,
+    "safe": {
+      "toehold": "0x914d7Fec6aaC8cd542e72Bca78B30650d45643d7",
+      "singleton": "0xfb1bffC9d739B8D520DaF37dF666da4C687191EA",
+      "factory": "0xC22834581EbC8527d974F8a1c97E1bEA4EF910BC",
+      "fallback": "0x017062a1dE2FE6b99BE3d9d37841FeD19F573804",
+      "multiCall": "0xA1dabEF33b3B82c7814B6D82A79e50F4AC44102B",
+      "apiUrl": "NOT SUPPORTED"
+    }
   }
 }

script/SafeConfig.sol

@@ -24,6 +24,7 @@ library SafeConfig {
                 || block.chainid == 480 // worldchain
                 || block.chainid == 999 // hyperevm
                 || block.chainid == 2741 // abstract
+                || block.chainid == 4326 // megaeth
                 || block.chainid == 5000 // mantle
                 || block.chainid == 8453 // base
                 || block.chainid == 9745 // plasma
@@ -58,6 +59,7 @@ library SafeConfig {
                 || block.chainid == 480 // worldchain
                 || block.chainid == 999 // hyperevm
                 || block.chainid == 2741 // abstract
+                || block.chainid == 4326 // megaeth
                 || block.chainid == 5000 // mantle
                 || block.chainid == 8453 // base
                 || block.chainid == 9745 // plasma
@@ -97,6 +99,7 @@ library SafeConfig {
                 || block.chainid == 146 // sonic
                 || block.chainid == 480 // worldchain
                 || block.chainid == 999 // hyperevm
+                || block.chainid == 4326 // megaeth
                 || block.chainid == 5000 // mantle
                 || block.chainid == 8453 // base
                 || block.chainid == 9745 // plasma

sh/common.sh

@@ -116,15 +116,24 @@ function verify_contract {
     shift
 
     declare _verify_etherscanApi
-    _verify_etherscanApi="$(get_config etherscanApi)"
+    _verify_etherscanApi="$(get_api_secret etherscanApi)"
+    if [[ ${_verify_etherscanApi:-null} == [nN][uU][lL][lL] ]] ; then
+        _verify_etherscanApi="$(get_config etherscanApi)"
+    fi
     declare -r _verify_etherscanApi
 
     declare _verify_blockscoutApi
-    _verify_blockscoutApi="$(get_config blockscoutApi)"
+    _verify_blockscoutApi="$(get_api_secret blockscoutApi)"
+    if [[ ${_verify_blockscoutApi:-null} == [nN][uU][lL][lL] ]] ; then
+        _verify_blockscoutApi="$(get_config blockscoutApi)"
+    fi
     declare -r _verify_blockscoutApi
 
     declare _verify_sourcifyApi
-    _verify_sourcifyApi="$(get_config sourcifyApi)"
+    _verify_sourcifyApi="$(get_api_secret sourcifyApi)"
+    if [[ ${_verify_sourcifyApi:-null} == [nN][uU][lL][lL] ]] ; then
+        _verify_sourcifyApi="$(get_config sourcifyApi)"
+    fi
     declare -r _verify_sourcifyApi
 
     if [[ ${_verify_etherscanApi:-null} != [nN][uU][lL][lL] ]] ; then

sh/common_gas.sh

@@ -27,15 +27,15 @@ function apply_gas_multiplier {
     declare -i _gas_estimate="$1"
     shift
 
-    # Mantle has funky gas rules, exclude it from this logic
-    if (( chainid != 5000 )) && (( _gas_estimate > eip7825_gas_limit )) ; then
+    # Mantle and MegaEth have funky gas rules, exclude them from this logic
+    if (( chainid != 4326 )) && (( chainid != 5000 )) && (( _gas_estimate > eip7825_gas_limit )) ; then
         echo 'Gas estimate without buffer /already/ exceeds the EIP-7825 limit' >&2
         exit 1
     fi
 
     declare -i _gas_limit=$((_gas_estimate * gas_estimate_multiplier / 100))
 
-    if (( chainid != 5000 )) && (( _gas_limit > eip7825_gas_limit )) ; then
+    if (( chainid != 4326 )) && (( chainid != 5000 )) && (( _gas_limit > eip7825_gas_limit )) ; then
         declare _gas_limit_keep_going
         IFS='' read -p 'Gas limit with multiplier exceeds EIP-7825 limit. Cap gas limit and keep going? [y/N]: ' -e -r -i n _gas_limit_keep_going
         declare -r _gas_limit_keep_going

sh/deploy_new_bridge_settler.sh

@@ -144,7 +144,7 @@ while (( ${#deploy_calldatas[@]} >= 3 )) ; do
 
     declare packed_signatures
     packed_signatures="$(retrieve_signatures bridge_settler_confirmation "$deploy_calldata" $operation "$target")"
-    
+
     declare -a args=(
         "$safe_address" "$execTransaction_sig"
         # to, value, data, operation, safeTxGas, baseGas, gasPrice, gasToken, refundReceiver, signatures
@@ -157,7 +157,7 @@ while (( ${#deploy_calldatas[@]} >= 3 )) ; do
     declare -i gas_limit
     gas_limit="$(apply_gas_multiplier $gas_estimate)"
     declare -r -i gas_limit
-    
+
     if [[ $wallet_type = 'frame' ]] ; then
         cast send --confirmations 10 --from "$signer" --rpc-url 'http://127.0.0.1:1248/' --chain $chainid --gas-price $gas_price --gas-limit $gas_limit "${wallet_args[@]}" $(get_config extraFlags) "${args[@]}"
     else

src/chains/MegaEth/BridgeSettler.sol

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: MIT
+pragma solidity =0.8.25;
+
+import {IERC20} from "@forge-std/interfaces/IERC20.sol";
+import {SettlerAbstract} from "../../SettlerAbstract.sol";
+import {IBridgeSettlerActions} from "../../bridge/IBridgeSettlerActions.sol";
+import {BridgeSettler, BridgeSettlerBase} from "../../bridge/BridgeSettler.sol";
+
+contract MegaEthBridgeSettler is BridgeSettler {
+    constructor(bytes20 gitCommit) BridgeSettlerBase(gitCommit) {
+        assert(block.chainid == 4326 || block.chainid == 31337);
+    }
+
+    function _dispatch(uint256 i, uint256 action, bytes calldata data)
+        internal
+        override(BridgeSettlerBase, SettlerAbstract)
+        returns (bool)
+    {
+        if (super._dispatch(i, action, data)) {
+            return true;
+        } else {
+            return false;
+        }
+    }
+}

src/chains/MegaEth/Common.sol

@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: MIT
+pragma solidity =0.8.25;
+
+import {SettlerBase} from "../../SettlerBase.sol";
+
+import {IERC20} from "@forge-std/interfaces/IERC20.sol";
+import {FreeMemory} from "../../utils/FreeMemory.sol";
+
+import {ISettlerActions} from "../../ISettlerActions.sol";
+import {ISignatureTransfer} from "@permit2/interfaces/ISignatureTransfer.sol";
+import {revertUnknownForkId} from "../../core/SettlerErrors.sol";
+
+// Solidity inheritance is stupid
+import {SettlerAbstract} from "../../SettlerAbstract.sol";
+
+abstract contract MegaEthMixin is FreeMemory, SettlerBase {
+    constructor() {
+        assert(block.chainid == 4326 || block.chainid == 31337);
+    }
+
+    function _dispatch(uint256 i, uint256 action, bytes calldata data)
+        internal
+        virtual
+        override(/* SettlerAbstract, */ SettlerBase)
+        DANGEROUS_freeMemory
+        returns (bool)
+    {
+        // This does not make use of `super._dispatch`. This chain's Settler is extremely
+        // stripped-down and has almost no capabilities
+        if (action == uint32(ISettlerActions.BASIC.selector)) {
+            (IERC20 sellToken, uint256 bps, address pool, uint256 offset, bytes memory _data) =
+                abi.decode(data, (IERC20, uint256, address, uint256, bytes));
+
+            basicSellToPool(sellToken, bps, pool, offset, _data);
+        } else {
+            return false;
+        }
+        return true;
+    }
+
+    function _uniV3ForkInfo(uint8 forkId)
+        internal
+        pure
+        override
+        returns (address factory, bytes32 initHash, uint32 callbackSelector)
+    {
+        revertUnknownForkId(forkId);
+    }
+}

src/chains/MegaEth/Intent.sol

@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: MIT
+pragma solidity =0.8.25;
+
+import {MegaEthSettlerMetaTxn} from "./MetaTxn.sol";
+import {SettlerIntent} from "../../SettlerIntent.sol";
+
+import {IERC20} from "@forge-std/interfaces/IERC20.sol";
+import {ISignatureTransfer} from "@permit2/interfaces/ISignatureTransfer.sol";
+import {ISettlerActions} from "../../ISettlerActions.sol";
+
+// Solidity inheritance is stupid
+import {SettlerAbstract} from "../../SettlerAbstract.sol";
+import {SettlerBase} from "../../SettlerBase.sol";
+import {SettlerMetaTxn} from "../../SettlerMetaTxn.sol";
+import {SettlerIntent} from "../../SettlerIntent.sol";
+import {AbstractContext, Context} from "../../Context.sol";
+import {Permit2PaymentAbstract} from "../../core/Permit2PaymentAbstract.sol";
+import {Permit2PaymentMetaTxn} from "../../core/Permit2Payment.sol";
+
+/// @custom:security-contact security@0x.org
+contract MegaEthSettlerIntent is SettlerIntent, MegaEthSettlerMetaTxn {
+    constructor(bytes20 gitCommit) MegaEthSettlerMetaTxn(gitCommit) {}
+
+    // Solidity inheritance is stupid
+    function executeMetaTxn(
+        AllowedSlippage calldata slippage,
+        bytes[] calldata actions,
+        bytes32, /* zid & affiliate */
+        address msgSender,
+        bytes calldata sig
+    ) public override(SettlerIntent, SettlerMetaTxn) returns (bool) {
+        return super.executeMetaTxn(slippage, actions, bytes32(0), msgSender, sig);
+    }
+
+    function _dispatch(uint256 i, uint256 action, bytes calldata data)
+        internal
+        override(MegaEthSettlerMetaTxn, SettlerBase, SettlerAbstract)
+        returns (bool)
+    {
+        return super._dispatch(i, action, data);
+    }
+
+    function _isForwarded() internal view override(AbstractContext, Context, SettlerIntent) returns (bool) {
+        return super._isForwarded();
+    }
+
+    function _msgData() internal view override(AbstractContext, Context, SettlerIntent) returns (bytes calldata) {
+        return super._msgData();
+    }
+
+    function _msgSender() internal view override(SettlerIntent, MegaEthSettlerMetaTxn) returns (address) {
+        return super._msgSender();
+    }
+
+    function _witnessTypeSuffix()
+        internal
+        pure
+        override(SettlerIntent, Permit2PaymentMetaTxn)
+        returns (string memory)
+    {
+        return super._witnessTypeSuffix();
+    }
+
+    function _mandatorySlippageCheck() internal pure override(SettlerBase, SettlerIntent) returns (bool) {
+        return super._mandatorySlippageCheck();
+    }
+
+    function _tokenId() internal pure override(SettlerIntent, SettlerMetaTxn, SettlerAbstract) returns (uint256) {
+        return super._tokenId();
+    }
+
+    function _dispatchVIP(uint256 action, bytes calldata data, bytes calldata sig)
+        internal
+        override(MegaEthSettlerMetaTxn, SettlerMetaTxn)
+        returns (bool)
+    {
+        return super._dispatchVIP(action, data, sig);
+    }
+
+    function _permitToSellAmountCalldata(ISignatureTransfer.PermitTransferFrom calldata permit)
+        internal
+        view
+        override(SettlerIntent, Permit2PaymentAbstract, Permit2PaymentMetaTxn)
+        returns (uint256)
+    {
+        return super._permitToSellAmountCalldata(permit);
+    }
+
+    function _permitToSellAmount(ISignatureTransfer.PermitTransferFrom memory permit)
+        internal
+        view
+        override(SettlerIntent, Permit2PaymentAbstract, Permit2PaymentMetaTxn)
+        returns (uint256)
+    {
+        return super._permitToSellAmount(permit);
+    }
+}