feat(MayanFacet): signed arbitrary destination-call payloads (EXSC-604)

config/clearSigningProposal.json

@@ -1572,7 +1572,7 @@
         }
       ]
     },
-    "startBridgeTokensViaMayan((bytes32 transactionId, string bridge, string integrator, address referrer, address sendingAssetId, address receiver, uint256 minAmount, uint256 destinationChainId, bool hasSourceSwaps, bool hasDestinationCall) _bridgeData, (bytes32 nonEVMReceiver, address mayanProtocol, bytes protocolData, address swapProtocol, bytes swapData, address middleToken, uint256 minMiddleAmount, address refundRecipient) _mayanData)": {
+    "startBridgeTokensViaMayan((bytes32 transactionId, string bridge, string integrator, address referrer, address sendingAssetId, address receiver, uint256 minAmount, uint256 destinationChainId, bool hasSourceSwaps, bool hasDestinationCall) _bridgeData, (bytes32 nonEVMReceiver, address mayanProtocol, bytes protocolData, address swapProtocol, bytes swapData, address middleToken, uint256 minMiddleAmount, address refundRecipient, bytes signature, uint256 deadline) _mayanData)": {
       "intent": "Bridge via Mayan",
       "interpolatedIntent": "Bridge {_bridgeData.minAmount} via Mayan to chain {_bridgeData.destinationChainId} for {_bridgeData.receiver}",
       "fields": [
@@ -4756,7 +4756,7 @@
         }
       ]
     },
-    "swapAndStartBridgeTokensViaMayan((bytes32 transactionId, string bridge, string integrator, address referrer, address sendingAssetId, address receiver, uint256 minAmount, uint256 destinationChainId, bool hasSourceSwaps, bool hasDestinationCall) _bridgeData, (address callTo, address approveTo, address sendingAssetId, address receivingAssetId, uint256 fromAmount, bytes callData, bool requiresDeposit)[] _swapData, (bytes32 nonEVMReceiver, address mayanProtocol, bytes protocolData, address swapProtocol, bytes swapData, address middleToken, uint256 minMiddleAmount, address refundRecipient) _mayanData)": {
+    "swapAndStartBridgeTokensViaMayan((bytes32 transactionId, string bridge, string integrator, address referrer, address sendingAssetId, address receiver, uint256 minAmount, uint256 destinationChainId, bool hasSourceSwaps, bool hasDestinationCall) _bridgeData, (address callTo, address approveTo, address sendingAssetId, address receivingAssetId, uint256 fromAmount, bytes callData, bool requiresDeposit)[] _swapData, (bytes32 nonEVMReceiver, address mayanProtocol, bytes protocolData, address swapProtocol, bytes swapData, address middleToken, uint256 minMiddleAmount, address refundRecipient, bytes signature, uint256 deadline) _mayanData)": {
       "intent": "Swap & Bridge via Mayan",
       "interpolatedIntent": "Swap then bridge {_bridgeData.minAmount} via Mayan to chain {_bridgeData.destinationChainId} for {_bridgeData.receiver}",
       "fields": [

config/mayan.json

@@ -1,4 +1,10 @@
 {
+  "staging": {
+    "backendSigner": "0x981CCF8c09633F6F2AF3fe661C285ca1DB09caE1"
+  },
+  "production": {
+    "backendSigner": "0xAF4B7A83591a6c4c8B9d1341C3F08BBc3b800fc5"
+  },
   "bridges": {
     "mainnet": {
       "bridge": "0x337685fdaB40D39bd02028545a4FfA7D287cC3E2"

docs/MayanFacet.md

@@ -12,10 +12,38 @@ graph LR;
 
 ## Receiver validation
 
-Before forwarding to Mayan, the facet validates that the order's destination receiver matches `BridgeData.receiver`:
+The facet has two trust models, partitioned strictly by `BridgeData.hasDestinationCall`:
+
+- **Plain bridges (`hasDestinationCall == false`)** — permissionless, unchanged: before forwarding to Mayan, the facet validates that the order's destination receiver matches `BridgeData.receiver`:
+  - **EVM destinations:** the receiver parsed from the Mayan protocol data (`destAddr`) must equal `BridgeData.receiver`.
+  - **Non-EVM destinations** (`BridgeData.receiver == NON_EVM_ADDRESS`): the receiver parsed from the protocol data must equal `MayanData.nonEVMReceiver` (full 32-byte comparison).
+- **Destination calls (`hasDestinationCall == true`)** — signature-gated (see [Arbitrary destination calls](#arbitrary-destination-calls)): the on-chain `_parseReceiver` check is **skipped** and the receiver is instead attested by a backend EIP-712 signature.
+
+## Arbitrary destination calls
+
+A Mayan Swift v2 order can carry a `customPayload` that instructs Mayan's destination-side executor to perform an **arbitrary call** (target + calldata) after delivery. That target/calldata **cannot be validated on-chain** against `BridgeData.receiver` — the whole point of a destination call is that funds/control flow go somewhere other than a plain receiver.
+
+Following the repo's opaque-calldata convention, this capability is unlocked **only** behind a backend EIP-712 signature. When `BridgeData.hasDestinationCall == true`, both entrypoints verify — before any deposit or swap, over the **as-submitted** `protocolData` and **pre-swap** `minAmount` — a signature from the authorized backend signer over:
+
+```text
+MayanDestinationCallPayload(
+    bytes32 transactionId,
+    bytes32 receiver,            // NON_EVM-aware: nonEVMReceiver when receiver == NON_EVM_ADDRESS
+    uint256 minAmount,           // pre-swap minAmount, as submitted
+    address sendingAssetId,
+    uint256 destinationChainId,
+    bool    hasDestinationCall,
+    address mayanProtocol,
+    bytes32 protocolDataHash,    // keccak256(MayanData.protocolData), which contains the customPayload
+    uint256 deadline
+)
+```
+
+The domain separator binds `block.chainid` and `address(this)` (the diamond, under delegatecall), so a signature is valid on exactly one chain and one diamond. `deadline` time-boxes every signature, and `BridgeData.transactionId` is consumed in diamond storage (CEI, before the external Mayan call) to prevent same-chain replay.
+
+### Trust assumption (destination calls)
 
-- **EVM destinations:** the receiver parsed from the Mayan protocol data (`destAddr`) must equal `BridgeData.receiver`.
-- **Non-EVM destinations** (`BridgeData.receiver == NON_EVM_ADDRESS`): the receiver parsed from the protocol data must equal `MayanData.nonEVMReceiver` (full 32-byte comparison).
+On the destination-call path the receiver is **signer-attested, not on-chain-enforced**: the facet does not (and cannot) validate the opaque call target. The backend is trusted to only sign payloads it constructed for legitimate routes. A leaked signer key can authorize an arbitrary destination call, but the blast radius is bounded to the funds of the specific signed transaction — the facet custodies nothing persistently. The signer is **immutable**; rotation is a governance action (deploy a new facet with the new signer and run `diamondCut` through the Safe/timelock). There is deliberately **no owner setter** for it.
 
 ### HyperCore deposits
 
@@ -62,6 +90,8 @@ The methods listed above take a variable labeled `_mayanData`. This data is spec
 /// @param minMiddleAmount The minimum middleToken amount that must result from the swap
 /// @param refundRecipient The address that receives excess native value and swap leftovers;
 ///        must be the user, never the relayer, so refunds are not stranded on a relayer
+/// @param signature The backend EIP-712 signature; consumed only when hasDestinationCall
+/// @param deadline The signature expiry; enforced only on the signed destination-call path
 struct MayanData {
   bytes32 nonEVMReceiver;
   address mayanProtocol;
@@ -71,6 +101,8 @@ struct MayanData {
   address middleToken;
   uint256 minMiddleAmount;
   address refundRecipient;
+  bytes signature;
+  uint256 deadline;
 }
 ```
 

script/demoScripts/demoMayan.ts

@@ -85,6 +85,9 @@ const main = async () => {
     middleToken: '0x0000000000000000000000000000000000000000',
     minMiddleAmount: 0,
     refundRecipient: address,
+    // Destination-call signature fields; unused on this plain (non-dest-call) path
+    signature: '0x',
+    deadline: 0,
   }
 
   console.info('Dev Wallet Address: ', address)

script/deploy/facets/DeployMayanFacet.s.sol

@@ -27,6 +27,19 @@ contract DeployScript is DeployScriptBase {
             string.concat(".bridges.", network, ".bridge")
         );
 
-        return abi.encode(bridge);
+        string memory json = vm.readFile(path);
+
+        // check if production or staging
+        address backendSigner;
+        if (
+            keccak256(abi.encodePacked(fileSuffix)) ==
+            keccak256(abi.encodePacked("staging."))
+        ) {
+            backendSigner = json.readAddress(".staging.backendSigner");
+        } else {
+            backendSigner = json.readAddress(".production.backendSigner");
+        }
+
+        return abi.encode(bridge, backendSigner);
     }
 }

script/deploy/resources/deployRequirements.json

@@ -797,6 +797,20 @@
       }
     }
   },
+  "MayanFacet": {
+    "configData": {
+      "_mayan": {
+        "configFileName": "mayan.json",
+        "keyInConfigFile": ".bridges.<NETWORK>.bridge",
+        "allowToDeployWithZeroAddress": "false"
+      },
+      "_backendSigner": {
+        "configFileName": "mayan.json",
+        "keyInConfigFile": ".<ENVIRONMENT>.backendSigner",
+        "allowToDeployWithZeroAddress": "false"
+      }
+    }
+  },
   "NEARIntentsFacet": {
     "configData": {
       "_backendSigner": {