Merge pull request #22 from flashbots/tx-proxy

Proxy eth_sendRawTransaction to builder

Author: avalonche

src/proxy.rs

@@ -9,6 +9,8 @@ use std::{future::Future, pin::Pin};
 use tower::{Layer, Service};
 use tracing::debug;
 
+const MULTIPLEX_METHODS: [&str; 2] = ["engine_", "eth_sendRawTransaction"];
+
 #[derive(Debug, Clone)]
 pub struct ProxyLayer {
     target_url: Uri,
@@ -84,7 +86,7 @@ where
                 message = "received json rpc request for",
                 method = method.method
             );
-            if method.method.starts_with("engine_") {
+            if PROXY_METHODS.iter().any(|&m| method.method.starts_with(m)) {
                 // let rpc server handle engine rpc requests
                 let res = inner.call(req).await.map_err(|e| e.into())?;
                 Ok(res)

src/server.rs

@@ -1,4 +1,5 @@
 use alloy::primitives::B256;
+use alloy_primitives::Bytes;
 use alloy_rpc_types_engine::{
     ExecutionPayload, ExecutionPayloadV3, ForkchoiceState, ForkchoiceUpdated, PayloadId,
     PayloadStatus,
@@ -14,7 +15,7 @@ use op_alloy_rpc_types_engine::{
 };
 use reth_rpc_layer::AuthClientService;
 use std::sync::Arc;
-use tracing::{error, info};
+use tracing::{debug, error, info};
 
 #[rpc(server, client, namespace = "engine")]
 pub trait EngineApi {
@@ -40,6 +41,12 @@ pub trait EngineApi {
     ) -> RpcResult<PayloadStatus>;
 }
 
+#[rpc(server, client, namespace = "eth")]
+pub trait EthApi {
+    #[method(name = "sendRawTransaction")]
+    async fn send_raw_transaction(&self, bytes: Bytes) -> RpcResult<B256>;
+}
+
 pub struct EthEngineApi<S = AuthClientService<HttpBackend>> {
     l2_client: Arc<HttpClient<S>>,
     builder_client: Arc<HttpClient<S>>,
@@ -60,6 +67,36 @@ impl<S> EthEngineApi<S> {
     }
 }
 
+#[async_trait]
+impl EthApiServer for EthEngineApi {
+    async fn send_raw_transaction(&self, bytes: Bytes) -> RpcResult<B256> {
+        debug!(
+            message = "received send_raw_transaction",
+            "bytes_len" = bytes.len()
+        );
+        let builder = self.builder_client.clone();
+        let tx_bytes = bytes.clone();
+        tokio::spawn(async move {
+            builder.send_raw_transaction(tx_bytes).await.map_err(|e| {
+                error!(message = "error calling send_raw_transaction for builder", "error" = %e);
+            })
+        });
+        self.l2_client
+            .send_raw_transaction(bytes)
+            .await
+            .map_err(|e| match e {
+                ClientError::Call(err) => err, // Already an ErrorObjectOwned, so just return it
+                other_error => {
+                    error!(
+                        message = "error calling send_raw_transaction for l2 client",
+                        "error" = %other_error,
+                    );
+                    ErrorCode::InternalError.into()
+                }
+            })
+    }
+}
+
 #[async_trait]
 impl EngineApiServer for EthEngineApi {
     async fn fork_choice_updated_v3(