Add ExactEvmConfig for smart wallet deployment control and support EOA v,r,s signature overload

* Add ExactEvmConfig struct with deploy_erc4337_with_eip6492 flag to control smart wallet deployment behavior
* Implement Default trait for ExactEvmConfig with deployment disabled by default
* Add with_config and update with_networks constructors to accept custom configuration
* Reject undeployed smart wallet settlements when deployment is disabled via config
* Add transferWithAuthorizationVRS function

Author: gitctrlx

r402-evm/src/exact/facilitator.rs

@@ -17,9 +17,31 @@ use crate::chain::{NetworkConfig, parse_caip2};
 use crate::exact::types::{
     ExactPayload, ExactRequirementsExtra, SCHEME_EXACT, TransferWithAuthorization,
     authorizationStateCall, balanceOfCall, isValidSignatureCall, transferWithAuthorizationCall,
+    transferWithAuthorizationVRSCall,
 };
 use crate::networks::known_networks;
 
+/// Configuration options for the EVM exact scheme facilitator.
+///
+/// Corresponds to Python SDK's `ExactEvmSchemeConfig` in `exact/facilitator.py`.
+#[derive(Debug, Clone, Copy)]
+pub struct ExactEvmConfig {
+    /// Whether to deploy ERC-4337 smart wallets via ERC-6492 factory calls
+    /// during settlement. When `false`, payments from undeployed smart wallets
+    /// will be rejected at settlement time.
+    ///
+    /// Default: `false`.
+    pub deploy_erc4337_with_eip6492: bool,
+}
+
+impl Default for ExactEvmConfig {
+    fn default() -> Self {
+        Self {
+            deploy_erc4337_with_eip6492: false,
+        }
+    }
+}
+
 /// EVM facilitator implementation for the "exact" payment scheme.
 ///
 /// Verifies EIP-3009 authorization signatures and settles payments by
@@ -34,6 +56,7 @@ use crate::networks::known_networks;
 pub struct ExactEvmFacilitator<P> {
     provider: P,
     signer_address: Address,
+    config: ExactEvmConfig,
     #[allow(dead_code)]
     networks: Vec<NetworkConfig>,
 }
@@ -45,24 +68,37 @@ where
     /// Creates a new facilitator with the given provider and signer address.
     ///
     /// The `signer_address` is the facilitator's wallet that will submit
-    /// settlement transactions.
+    /// settlement transactions. Uses default configuration.
     pub fn new(provider: P, signer_address: Address) -> Self {
         Self {
             provider,
             signer_address,
+            config: ExactEvmConfig::default(),
+            networks: known_networks(),
+        }
+    }
+
+    /// Creates a facilitator with custom configuration.
+    pub fn with_config(provider: P, signer_address: Address, config: ExactEvmConfig) -> Self {
+        Self {
+            provider,
+            signer_address,
+            config,
             networks: known_networks(),
         }
     }
 
-    /// Creates a facilitator with custom network configurations.
+    /// Creates a facilitator with custom network configurations and config.
     pub fn with_networks(
         provider: P,
         signer_address: Address,
+        config: ExactEvmConfig,
         networks: Vec<NetworkConfig>,
     ) -> Self {
         Self {
             provider,
             signer_address,
+            config,
             networks,
         }
     }
@@ -352,6 +388,13 @@ where
         if has_deployment_info(&sig_data) {
             let code = self.get_code(from).await.unwrap_or_default();
             if code.is_empty() {
+                if !self.config.deploy_erc4337_with_eip6492 {
+                    return SettleResponse::error(
+                        "undeployed_smart_wallet",
+                        "Smart wallet deployment is disabled by configuration",
+                        &network,
+                    );
+                }
                 // Smart wallet not deployed — attempt factory deployment
                 let deploy_tx = alloy_rpc_types_eth::TransactionRequest::default()
                     .from(self.signer_address)
@@ -390,19 +433,39 @@ where
 
         // Use inner signature (stripped of ERC-6492 wrapper) for settlement
         let inner_sig = &sig_data.inner_signature;
-
-        // Build transferWithAuthorization calldata (always use bytes overload
-        // for compatibility with both EOA and smart wallet signatures)
-        let call = transferWithAuthorizationCall {
-            from,
-            to,
-            value,
-            validAfter: valid_after,
-            validBefore: valid_before,
-            nonce: nonce_bytes.into(),
-            signature: Bytes::from(inner_sig.clone()),
+        let is_ecdsa = inner_sig.len() == 65;
+
+        // Build transferWithAuthorization calldata.
+        // EOA (65-byte): use v,r,s overload for maximum compatibility.
+        // Smart wallet (non-65-byte): use bytes overload.
+        let calldata = if is_ecdsa {
+            let r = B256::from_slice(&inner_sig[..32]);
+            let s = B256::from_slice(&inner_sig[32..64]);
+            let v = inner_sig[64];
+            let call = transferWithAuthorizationVRSCall {
+                from,
+                to,
+                value,
+                validAfter: valid_after,
+                validBefore: valid_before,
+                nonce: nonce_bytes.into(),
+                v,
+                r,
+                s,
+            };
+            call.abi_encode()
+        } else {
+            let call = transferWithAuthorizationCall {
+                from,
+                to,
+                value,
+                validAfter: valid_after,
+                validBefore: valid_before,
+                nonce: nonce_bytes.into(),
+                signature: Bytes::from(inner_sig.clone()),
+            };
+            call.abi_encode()
         };
-        let calldata = call.abi_encode();
 
         // Submit settlement transaction
         let tx = alloy_rpc_types_eth::TransactionRequest::default()

r402-evm/src/exact/types.rs

@@ -64,7 +64,8 @@ pub struct ExactRequirementsExtra {
 }
 
 sol! {
-    /// ERC-3009 `transferWithAuthorization` function.
+    /// ERC-3009 `transferWithAuthorization` function (bytes overload).
+    /// Used for smart wallet signatures (EIP-1271).
     #[derive(Debug, PartialEq, Eq)]
     function transferWithAuthorization(
         address from,
@@ -76,6 +77,22 @@ sol! {
         bytes memory signature
     ) external;
 
+    /// ERC-3009 `transferWithAuthorization` function (v,r,s overload).
+    /// Used for EOA signatures (65 bytes decomposed into v, r, s).
+    #[derive(Debug, PartialEq, Eq)]
+    #[sol(rename = "transferWithAuthorization")]
+    function transferWithAuthorizationVRS(
+        address from,
+        address to,
+        uint256 value,
+        uint256 validAfter,
+        uint256 validBefore,
+        bytes32 nonce,
+        uint8 v,
+        bytes32 r,
+        bytes32 s
+    ) external;
+
     /// ERC-3009 `authorizationState` view function.
     #[derive(Debug, PartialEq, Eq)]
     function authorizationState(

r402-evm/src/networks.rs

@@ -30,8 +30,17 @@ pub const ETHEREUM_MAINNET: ChainId = 1;
 /// Celo Mainnet chain ID.
 pub const CELO_MAINNET: ChainId = 42220;
 
-/// `MegaETH` Testnet chain ID.
-pub const MEGAETH_TESTNET: ChainId = 6342;
+/// `MegaETH` Mainnet (Frontier) chain ID.
+pub const MEGAETH_MAINNET: ChainId = 4326;
+
+/// `MegaETH` Testnet v2 chain ID.
+pub const MEGAETH_TESTNET: ChainId = 6343;
+
+/// Monad Mainnet chain ID.
+pub const MONAD_MAINNET: ChainId = 143;
+
+/// Monad Testnet chain ID.
+pub const MONAD_TESTNET: ChainId = 10143;
 
 /// USDC contract address on Base Mainnet.
 pub const USDC_BASE: Address = address!("833589fCD6eDb6E08f4c7C32D4f71b54bdA02913");
@@ -57,8 +66,15 @@ pub const USDC_AVALANCHE_FUJI: Address = address!("5425890298aed601595a70AB815c9
 /// USDC contract address on Celo.
 pub const USDC_CELO: Address = address!("cebA9300f2b948710d2653dD7B07f33A8B32118C");
 
-/// USDC contract address on `MegaETH` Testnet.
-pub const USDC_MEGAETH: Address = address!("2F24De1820e846B6C14EB8ED4dDfc4fdF7cc5149");
+/// USDM contract address on `MegaETH` Mainnet (Frontier).
+/// MegaETH uses USDM (MegaUSD) instead of Circle USDC.
+pub const USDM_MEGAETH: Address = address!("FAfDdbb3FC7688494971a79cc65DCa3EF82079E7");
+
+/// USDC contract address on Monad Mainnet (Circle native).
+pub const USDC_MONAD: Address = address!("754704Bc059F8C67012fEd69BC8A327a5aafb603");
+
+/// USDC contract address on Monad Testnet (Circle native).
+pub const USDC_MONAD_TESTNET: Address = address!("534b2f3A21130d7a60830c2Df862319e593943A3");
 
 /// Default EIP-712 domain name for USDC.
 pub const DEFAULT_USDC_NAME: &str = "USD Coin";
@@ -146,10 +162,29 @@ pub fn known_networks() -> Vec<NetworkConfig> {
             )],
         },
         NetworkConfig {
-            network: format!("eip155:{MEGAETH_TESTNET}"),
-            chain_id: MEGAETH_TESTNET,
+            network: format!("eip155:{MEGAETH_MAINNET}"),
+            chain_id: MEGAETH_MAINNET,
+            assets: vec![AssetInfo {
+                address: USDM_MEGAETH,
+                decimals: 18,
+                name: "MegaUSD".to_owned(),
+                version: "1".to_owned(),
+            }],
+        },
+        NetworkConfig {
+            network: format!("eip155:{MONAD_MAINNET}"),
+            chain_id: MONAD_MAINNET,
+            assets: vec![usdc_asset(
+                USDC_MONAD,
+                DEFAULT_USDC_NAME,
+                DEFAULT_USDC_VERSION,
+            )],
+        },
+        NetworkConfig {
+            network: format!("eip155:{MONAD_TESTNET}"),
+            chain_id: MONAD_TESTNET,
             assets: vec![usdc_asset(
-                USDC_MEGAETH,
+                USDC_MONAD_TESTNET,
                 DEFAULT_USDC_NAME,
                 DEFAULT_USDC_VERSION,
             )],

r402/src/server.rs

@@ -185,9 +185,10 @@ impl X402ResourceServer {
     #[must_use]
     pub fn has_registered_scheme(&self, network: &str, scheme: &str) -> bool {
         if let Some(schemes) = self.schemes.get(network)
-            && schemes.contains_key(scheme) {
-                return true;
-            }
+            && schemes.contains_key(scheme)
+        {
+            return true;
+        }
         let prefix = network.split(':').next().unwrap_or("");
         let wildcard = format!("{prefix}:*");
         self.schemes