feat: add WBTC OFT adapter

.env.example

@@ -27,6 +27,8 @@ ETHEREUM_SEPOLIA_RPC=
 ARBITRUM_SEPOLIA_RPC=https://sepolia-rollup.arbitrum.io/rpc
 OP_SEPOLIA_RPC=https://sepolia.optimism.io
 BASE_RPC=https://base-mainnet.public.blastapi.io
+# Pin Base fork to last block before Aave V3 froze WETH so Aave-dependent tests stay green.
+FORK_BLOCK_NUMBER=44880000
 ETHEREUM_RPC=https://eth-mainnet.public.blastapi.io
 ARBITRUM_ONE_RPC=https://arbitrum-one.public.blastapi.io
 OP_MAINNET_RPC=https://public-op-mainnet.fastnode.io

contracts/Repayer.sol

@@ -18,6 +18,7 @@ import {SuperchainStandardBridgeAdapter} from "./utils/SuperchainStandardBridgeA
 import {ArbitrumGatewayAdapter} from "./utils/ArbitrumGatewayAdapter.sol";
 import {GnosisOmnibridgeAdapter} from "./utils/GnosisOmnibridgeAdapter.sol";
 import {USDT0Adapter} from "./utils/USDT0Adapter.sol";
+import {WBTCOFTAdapter} from "./utils/WBTCOFTAdapter.sol";
 import {ERC7201Helper} from "./utils/ERC7201Helper.sol";
 
 /// @title Performs repayment to Liquidity Pools on same/different chains.
@@ -35,7 +36,8 @@ contract Repayer is
     SuperchainStandardBridgeAdapter,
     ArbitrumGatewayAdapter,
     GnosisOmnibridgeAdapter,
-    USDT0Adapter
+    USDT0Adapter,
+    WBTCOFTAdapter
 {
     using SafeERC20 for IERC20;
     using BitMaps for BitMaps.BitMap;
@@ -116,7 +118,8 @@ contract Repayer is
         address ethereumAmb,
         address usdt0Oft,
         address cctpV2TokenMessenger,
-        address cctpV2MessageTransmitter
+        address cctpV2MessageTransmitter,
+        address wbtcOft
     )
         CCTPV2Adapter(
             cctpTokenMessenger,
@@ -138,6 +141,7 @@ contract Repayer is
             ethereumAmb
         )
         USDT0Adapter(usdt0Oft)
+        WBTCOFTAdapter(wbtcOft)
     {
         ERC7201Helper.validateStorageLocation(
             STORAGE_LOCATION,
@@ -282,6 +286,9 @@ contract Repayer is
         } else
         if (provider == Provider.USDT0) {
             initiateTransferUSDT0(token, amount, destinationPool, destinationDomain, DOMAIN, _msgSender());
+        } else
+        if (provider == Provider.WBTC_OFT) {
+            initiateTransferWBTCOFT(token, amount, destinationPool, destinationDomain, DOMAIN, _msgSender());
         } else {
             // Unreachable atm, but could become so when more providers are added to enum.
             revert UnsupportedProvider();

contracts/interfaces/IRoute.sol

@@ -35,7 +35,8 @@ interface IRoute {
         ARBITRUM_GATEWAY,
         GNOSIS_OMNIBRIDGE,
         USDT0,
-        CCTP_V2
+        CCTP_V2,
+        WBTC_OFT
     }
 
     enum PoolType {
@@ -47,4 +48,5 @@ interface IRoute {
     error ProcessFailed();
     error UnsupportedDomain();
     error InvalidLength();
+    error InvalidToken();
 }

contracts/testing/TestRepayer.sol

@@ -22,7 +22,8 @@ contract TestRepayer is Repayer {
         address ethereumAmb,
         address usdt0Oft,
         address cctpV2TokenMessenger,
-        address cctpV2MessageTransmitter
+        address cctpV2MessageTransmitter,
+        address wbtcOft
     ) Repayer(
         localDomain,
         assets,
@@ -41,7 +42,8 @@ contract TestRepayer is Repayer {
         ethereumAmb,
         usdt0Oft,
         cctpV2TokenMessenger,
-        cctpV2MessageTransmitter
+        cctpV2MessageTransmitter,
+        wbtcOft
     ) {}
 
     function domainCCTP(Domain destinationDomain) public pure override returns (uint32) {

contracts/testing/TestWBTCOFT.sol

@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: LGPL-3.0-only
+pragma solidity 0.8.28;
+
+import {IERC20, SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import {IOFT} from "../interfaces/IOFT.sol";
+import {SendParam, MessagingFee} from "../interfaces/ILayerZero.sol";
+
+/// @notice Minimal WBTC-style token with permissioned burn for testing.
+/// The OFT calls burn() directly without needing an approval from the token holder.
+/// To simplify the test setup, burn function here can be called by anyone.
+contract TestWBTC is ERC20 {
+    constructor() ERC20("TestWBTC", "tWBTC") {}
+
+    function mint(address to, uint256 amount) external {
+        _mint(to, amount);
+    }
+
+    function burn(address from, uint256 amount) public {
+        _burn(from, amount);
+    }
+
+    function decimals() public pure override returns (uint8) {
+        return 8;
+    }
+}
+
+/// @notice Test mock for a WBTCOFTAdapter-style OFT (Ethereum adapter pattern).
+/// Locks the underlying token via transferFrom — requires approval from the sender.
+contract TestWBTCOFTAdapter is IOFT {
+    using SafeERC20 for IERC20;
+
+    address private immutable TOKEN;
+    uint256 public constant NATIVE_FEE = 1e10;
+
+    error EtherTransferFailed();
+
+    constructor(address _token) {
+        TOKEN = _token;
+    }
+
+    function token() public view returns (address) {
+        return TOKEN;
+    }
+
+    function quoteSend(SendParam calldata, bool) external pure returns (MessagingFee memory) {
+        return MessagingFee(NATIVE_FEE, 0);
+    }
+
+    function send(
+        SendParam calldata _sendParam,
+        MessagingFee calldata,
+        address refundAddress
+    ) external payable virtual {
+        IERC20(TOKEN).safeTransferFrom(msg.sender, address(this), _sendParam.amountLD);
+        (bool success,) = payable(refundAddress).call{value: msg.value - NATIVE_FEE}("");
+        if (!success) revert EtherTransferFailed();
+    }
+}
+
+/// @notice Test mock for a native-OFT-style WBTC OFT (non-Ethereum chains).
+/// Calls token.burn() directly — no approval needed because burn is permissioned to the OFT.
+contract TestWBTCOFTNative is TestWBTCOFTAdapter {
+    constructor(address _token) TestWBTCOFTAdapter(_token) {}
+
+    function send(
+        SendParam calldata _sendParam,
+        MessagingFee calldata,
+        address refundAddress
+    ) external payable override {
+        TestWBTC(token()).burn(msg.sender, _sendParam.amountLD);
+        (bool success,) = payable(refundAddress).call{value: msg.value - NATIVE_FEE}("");
+        if (!success) revert EtherTransferFailed();
+    }
+}

contracts/utils/USDT0Adapter.sol

@@ -14,8 +14,6 @@ abstract contract USDT0Adapter is LayerZeroHelper {
     /// On all other chains it is an OUpgradeable (burns/mints USDT0 directly — no approval needed).
     IOFT immutable public USDT0_OFT;
 
-    error InvalidToken();
-
     event USDT0Transfer(address token, address receiver, uint32 dstEid, uint256 amount);
 
     constructor(address usdt0Oft) {

contracts/utils/WBTCOFTAdapter.sol

@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: LGPL-3.0-only
+pragma solidity 0.8.28;
+
+import {IERC20, SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+import {SendParam, MessagingFee} from ".././interfaces/ILayerZero.sol";
+import {IOFT} from ".././interfaces/IOFT.sol";
+import {LayerZeroHelper} from "./LayerZeroHelper.sol";
+
+abstract contract WBTCOFTAdapter is LayerZeroHelper {
+    using SafeERC20 for IERC20;
+
+    /// @notice The WBTC OFT contract on the local chain.
+    /// On Ethereum this is a WBTCOFTAdapter (locks/unlocks canonical WBTC via transferFrom).
+    /// On all other supported chains it is an OFT that burns/mints WBTC directly — no approval needed.
+    IOFT immutable public WBTC_OFT;
+
+    event WBTCOFTTransfer(address token, address receiver, uint32 dstEid, uint256 amount);
+
+    constructor(address wbtcOft) {
+        // No check for address(0): allows deployment on chains where WBTC OFT is not available.
+        WBTC_OFT = IOFT(wbtcOft);
+    }
+
+    /// @notice Initiates a cross-chain transfer of WBTC via the LayerZero OFT.
+    /// @dev The caller must supply sufficient native currency (msg.value) to cover the LayerZero
+    /// messaging fee. Any excess is refunded to `caller` by the OFT contract.
+    /// amountLD and minAmountLD are set equal — no slippage is accepted.
+    /// @param token The ERC-20 token to bridge. Must match WBTC_OFT.token().
+    /// @param amount The amount to send in local decimals (8 for WBTC).
+    /// @param destinationPool The recipient address on the destination chain.
+    /// @param destinationDomain The destination domain.
+    /// @param localDomain The local domain; used to decide whether approval is needed.
+    /// @param caller The address that initiated the call; used as the LayerZero fee refund address.
+    function initiateTransferWBTCOFT(
+        IERC20 token,
+        uint256 amount,
+        address destinationPool,
+        Domain destinationDomain,
+        Domain localDomain,
+        address caller
+    ) internal {
+        IOFT oft = WBTC_OFT;
+        require(address(oft) != address(0), ZeroAddress());
+        require(address(token) == oft.token(), InvalidToken());
+
+        // On Ethereum the OFT is a WBTCOFTAdapter that pulls tokens via transferFrom.
+        // On other chains the OFT burns from msg.sender directly — no approval needed.
+        if (localDomain == Domain.ETHEREUM) {
+            token.forceApprove(address(oft), amount);
+        }
+
+        uint32 dstEid = layerZeroEndpointId(destinationDomain);
+
+        SendParam memory sendParam = SendParam({
+            dstEid: dstEid,
+            to: _addressToBytes32(destinationPool),
+            amountLD: amount,
+            minAmountLD: amount,
+            extraOptions: new bytes(0),
+            composeMsg: new bytes(0),
+            oftCmd: new bytes(0)
+        });
+
+        MessagingFee memory fee = MessagingFee(msg.value, 0);
+        // solhint-disable-next-line check-send-result
+        oft.send{value: msg.value}(sendParam, fee, caller);
+
+        emit WBTCOFTTransfer(address(token), destinationPool, dstEid, amount);
+    }
+}

coverage-baseline.json

@@ -1,6 +1,6 @@
 {
   "lines": "99.61",
   "functions": "99.56",
-  "branches": "92.65",
+  "branches": "92.73",
   "statements": "99.61"
 }

hardhat.config.ts

@@ -818,7 +818,13 @@ const config: HardhatUserConfig = {
         url: isSet(process.env.DRY_RUN) || isSet(process.env.FORK_TEST)
           ? process.env[`${process.env.DRY_RUN || process.env.FORK_TEST}_RPC`]!
           : (process.env.FORK_PROVIDER || process.env.BASE_RPC || "https://base-mainnet.public.blastapi.io"),
-        blockNumber: process.env.FORK_BLOCK_NUMBER ? parseInt(process.env.FORK_BLOCK_NUMBER) : undefined,
+        // FORK_BLOCK_NUMBER only applies to the default Base fork, not to FORK_TEST or DRY_RUN
+        // because each chain has its own block-number space.
+        blockNumber: process.env.FORK_BLOCK_NUMBER
+          && !isSet(process.env.DRY_RUN)
+          && !isSet(process.env.FORK_TEST)
+          ? parseInt(process.env.FORK_BLOCK_NUMBER)
+          : undefined,
       },
       accounts: isSet(process.env.DRY_RUN)
         ? [{privateKey: process.env.PRIVATE_KEY!, balance: "100000000000000000000"}]

network.config.ts

@@ -93,6 +93,7 @@ export enum Provider {
   GNOSIS_OMNIBRIDGE = "GNOSIS_OMNIBRIDGE",
   USDT0 = "USDT0",
   CCTP_V2 = "CCTP_V2",
+  WBTC_OFT = "WBTC_OFT",
 }
 
 export enum Token {
@@ -202,6 +203,7 @@ export interface NetworkConfig {
   GnosisUSDCxDAI?: string;
   GnosisUSDCTransmuter?: string;
   USDT0OFT?: string;
+  WBTCOFT?: string;
   Tokens: {
     [Token.USDC]: TokenInfo;
     [Token.USDT]?: TokenInfo;
@@ -260,6 +262,7 @@ export const networkConfig: NetworksConfig = {
     Omnibridge: "0x88ad09518695c6c3712AC10a214bE5109a655671",
     GnosisAMB: "0x4C36d2919e407f0Cc2Ee3c993ccF8ac26d9CE64e",
     USDT0OFT: "0x6C96dE32CEa08842dcc4058c14d3aaAD7Fa41dee",
+    WBTCOFT: "0x0555E30da8f98308EdB960aa94C0Db47230d2B9c",
     Tokens: {
       USDC: tokenInfo("0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48", 6),
       USDT: tokenInfo("0xdAC17F958D2ee523a2206206994597C13D831ec7", 6),
@@ -397,6 +400,7 @@ export const networkConfig: NetworksConfig = {
       Omnibridge: "0x88ad09518695c6c3712AC10a214bE5109a655671",
       GnosisAMB: "0x4C36d2919e407f0Cc2Ee3c993ccF8ac26d9CE64e",
       USDT0OFT: "0x6C96dE32CEa08842dcc4058c14d3aaAD7Fa41dee",
+      WBTCOFT: "0x0555E30da8f98308EdB960aa94C0Db47230d2B9c",
       Tokens: {
         USDC: tokenInfo("0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48", 6),
         USDT: tokenInfo("0xdAC17F958D2ee523a2206206994597C13D831ec7", 6),
@@ -634,6 +638,7 @@ export const networkConfig: NetworksConfig = {
     StargateTreasurer: "0x644abb1e17291b4403966119d15Ab081e4a487e9",
     EverclearFeeAdapter: "0xd0185bfb8107c5b2336bC73cE3fdd9Bfb504540e",
     OptimismStandardBridge: "0x4200000000000000000000000000000000000010",
+    WBTCOFT: "0xC3f854B2970f8727D28527ECE33176faC67FeF48",
     Tokens: {
       USDC: tokenInfo("0x0b2C639c533813f4Aa9D7837CAf62653d097Ff85", 6),
       USDT: tokenInfo("0x94b008aA00579c1307B0EF2c499aD98a8ce58e58", 6),
@@ -779,6 +784,7 @@ export const networkConfig: NetworksConfig = {
       AcrossV3SpokePool: "0x6f26Bf09B1C792e3228e5467807a900A503c0281",
       StargateTreasurer: "0x644abb1e17291b4403966119d15Ab081e4a487e9",
       EverclearFeeAdapter: "0xd0185bfb8107c5b2336bC73cE3fdd9Bfb504540e",
+      WBTCOFT: "0xC3f854B2970f8727D28527ECE33176faC67FeF48",
       Tokens: {
         USDC: tokenInfo("0x0b2C639c533813f4Aa9D7837CAf62653d097Ff85", 6),
         USDT: tokenInfo("0x94b008aA00579c1307B0EF2c499aD98a8ce58e58", 6),
@@ -1180,6 +1186,7 @@ export const networkConfig: NetworksConfig = {
     AcrossV3SpokePool: "0x09aea4b2242abC8bb4BB78D537A67a245A7bEC64",
     StargateTreasurer: "0xd47b03ee6d86Cf251ee7860FB2ACf9f91B9fD4d7",
     EverclearFeeAdapter: "0xd0185bfb8107c5b2336bC73cE3fdd9Bfb504540e",
+    WBTCOFT: "0x0555E30da8f98308EdB960aa94C0Db47230d2B9c",
     Tokens: {
       USDC: tokenInfo("0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913", 6),
       USDT: tokenInfo("0xfde4C96c8593536E31F229EA8f37b2ADa2699bb2", 6),
@@ -1303,6 +1310,7 @@ export const networkConfig: NetworksConfig = {
       AcrossV3SpokePool: "0x09aea4b2242abC8bb4BB78D537A67a245A7bEC64",
       StargateTreasurer: "0xd47b03ee6d86Cf251ee7860FB2ACf9f91B9fD4d7",
       EverclearFeeAdapter: "0xd0185bfb8107c5b2336bC73cE3fdd9Bfb504540e",
+      WBTCOFT: "0x0555E30da8f98308EdB960aa94C0Db47230d2B9c",
       Tokens: {
         USDC: tokenInfo("0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913", 6),
         USDT: tokenInfo("0xfde4C96c8593536E31F229EA8f37b2ADa2699bb2", 6),
@@ -1659,6 +1667,7 @@ export const networkConfig: NetworksConfig = {
     StargateTreasurer: "0x6D205337F45D6850c3c3006e28d5b52c8a432c35",
     EverclearFeeAdapter: "0x877Fd0A881B63eBE413124EeE6abbCD7E82cf10b",
     USDT0OFT: "0xc07bE8994D035631c36fb4a89C918CeFB2f03EC3",
+    WBTCOFT: "0x0555E30da8f98308EdB960aa94C0Db47230d2B9c",
     Tokens: {
       USDC: tokenInfo("0x078D782b760474a361dDA0AF3839290b0EF57AD6", 6),
       USDT: tokenInfo("0x9151434b16b9763660705744891fA906F660EcC5", 6),
@@ -1747,6 +1756,7 @@ export const networkConfig: NetworksConfig = {
       StargateTreasurer: "0x6D205337F45D6850c3c3006e28d5b52c8a432c35",
       EverclearFeeAdapter: "0x877Fd0A881B63eBE413124EeE6abbCD7E82cf10b",
       USDT0OFT: "0xc07bE8994D035631c36fb4a89C918CeFB2f03EC3",
+      WBTCOFT: "0x0555E30da8f98308EdB960aa94C0Db47230d2B9c",
       Tokens: {
         USDC: tokenInfo("0x078D782b760474a361dDA0AF3839290b0EF57AD6", 6),
         USDT: tokenInfo("0x9151434b16b9763660705744891fA906F660EcC5", 6),
@@ -1843,6 +1853,7 @@ export const networkConfig: NetworksConfig = {
     AcrossV3SpokePool: "0x4e8E101924eDE233C13e2D8622DC8aED2872d505",
     StargateTreasurer: "0x0a6A15964fEe494A881338D65940430797F0d97C",
     EverclearFeeAdapter: "0xd0185bfb8107c5b2336bC73cE3fdd9Bfb504540e",
+    WBTCOFT: "0x0555E30da8f98308EdB960aa94C0Db47230d2B9c",
     Tokens: {
       USDC: tokenInfo("0x8AC76a51cc950d9822D68b83fE1Ad97B32Cd580d", 18),
       WBTC: tokenInfo("0x7130d2A12B9BCbFAe4f2634d864A1Ee1Ce3Ead9c", 18),
@@ -1897,6 +1908,7 @@ export const networkConfig: NetworksConfig = {
       AcrossV3SpokePool: "0x4e8E101924eDE233C13e2D8622DC8aED2872d505",
       StargateTreasurer: "0x0a6A15964fEe494A881338D65940430797F0d97C",
       EverclearFeeAdapter: "0xd0185bfb8107c5b2336bC73cE3fdd9Bfb504540e",
+      WBTCOFT: "0x0555E30da8f98308EdB960aa94C0Db47230d2B9c",
       Tokens: {
         USDC: tokenInfo("0x8AC76a51cc950d9822D68b83fE1Ad97B32Cd580d", 18),
         WBTC: tokenInfo("0x7130d2A12B9BCbFAe4f2634d864A1Ee1Ce3Ead9c", 18),
@@ -2597,6 +2609,7 @@ export interface StandaloneRepayerConfig {
   GnosisUSDCTransmuter?: string;
   GnosisAMB?: string;
   USDT0OFT?: string;
+  WBTCOFT?: string;
   // Repayer tokens are used from the general network config.
   WrappedNativeToken: string;
   RepayerRoutes: RepayerRoutesConfig;

scripts/common.ts

@@ -52,6 +52,7 @@ export const ProviderSolidity = {
   GNOSIS_OMNIBRIDGE: 7n,
   USDT0: 8n,
   CCTP_V2: 9n,
+  WBTC_OFT: 10n,
 };
 
 export const DomainSolidity = {
@@ -109,6 +110,7 @@ export const SolidityProvider: { [n: number]: Provider } = {
   7: Provider.GNOSIS_OMNIBRIDGE,
   8: Provider.USDT0,
   9: Provider.CCTP_V2,
+  10: Provider.WBTC_OFT,
 };
 
 export const CCTPDomain: { [n: number]: Network } = {