always fetch latest nonce for 7702 authorizations (#20)

Author: joaquim-verges

core/src/signer.rs

@@ -194,7 +194,7 @@ pub trait AccountSigner {
         options: Self::SigningOptions,
         chain_id: u64,
         address: Address,
-        nonce: alloy::primitives::U256,
+        nonce: u64,
         credentials: &SigningCredential,
     ) -> impl std::future::Future<Output = Result<SignedAuthorization, EngineError>> + Send;
 }
@@ -355,14 +355,14 @@ impl AccountSigner for EoaSigner {
         options: EoaSigningOptions,
         chain_id: u64,
         address: Address,
-        nonce: U256,
+        nonce: u64,
         credentials: &SigningCredential,
     ) -> Result<SignedAuthorization, EngineError> {
         // Create the Authorization struct that both clients expect
         let authorization = Authorization {
             chain_id: U256::from(chain_id),
             address,
-            nonce: nonce.to::<u64>(),
+            nonce,
         };
         match credentials {
             SigningCredential::Vault(auth_method) => {

executors/src/eip7702_executor/send.rs

@@ -96,6 +96,13 @@ pub enum Eip7702SendError {
         inner_error: Option<EngineError>,
     },
 
+    #[error("Failed to fetch nonce: {message}")]
+    #[serde(rename_all = "camelCase")]
+    NonceFetchError {
+        message: String,
+        inner_error: Option<EngineError>,
+    },
+
     #[error("Failed to call bundler: {message}")]
     BundlerCallError { message: String },
 
@@ -264,7 +271,13 @@ where
 
         // 5. Sign authorization if needed
         let authorization = if !is_minimal_account {
-            let nonce = job_data.nonce.unwrap_or_default();
+            let nonce = get_eoa_nonce(&chain, job_data.eoa_address)
+                .await
+                .map_err(|e| Eip7702SendError::NonceFetchError {
+                    message: format!("Failed to fetch nonce: {e}"),
+                    inner_error: Some(e),
+                })
+                .map_err_fail()?;
 
             let auth = self
                 .eoa_signer
@@ -511,3 +524,18 @@ async fn check_is_7702_minimal_account(
 
     Ok(is_delegated)
 }
+
+async fn get_eoa_nonce(chain: &impl Chain, eoa_address: Address) -> Result<u64, EngineError> {
+    chain
+        .provider()
+        .get_transaction_count(eoa_address)
+        .await
+        .map_err(|e| EngineError::RpcError {
+            chain_id: chain.chain_id(),
+            rpc_url: chain.rpc_url().to_string(),
+            message: format!("Failed to get nonce for address {}: {}", eoa_address, e),
+            kind: RpcErrorKind::InternalError {
+                message: e.to_string(),
+            },
+        })
+}