refactor: type the json-rpc in the flashbots rpc

Author: prestwich

src/tasks/submit/flashbots/provider.rs

@@ -1,16 +1,20 @@
 //! A generic Flashbots bundle API wrapper.
+use std::borrow::Cow;
+
 use crate::config::BuilderConfig;
 use alloy::{
     primitives::{BlockNumber, keccak256},
-    rpc::types::mev::{EthBundleHash, MevSendBundle, SimBundleResponse},
+    rpc::{
+        json_rpc::{Id, Response, ResponsePayload, RpcRecv, RpcSend},
+        types::mev::{EthBundleHash, MevSendBundle, SimBundleResponse},
+    },
     signers::Signer,
 };
-use eyre::Context as _;
 use init4_bin_base::utils::signer::LocalOrAws;
 use reqwest::header::CONTENT_TYPE;
 use serde_json::json;
 
-/// A wrapper over a `Provider` that adds Flashbots MEV bundle helpers.
+/// An RPC connection to relevant Flashbots endpoints.
 #[derive(Debug)]
 pub struct Flashbots {
     /// The base URL for the Flashbots API.
@@ -34,48 +38,43 @@ impl Flashbots {
     }
 
     /// Sends a bundle  via `mev_sendBundle`.
-    pub async fn send_bundle(&self, bundle: MevSendBundle) -> eyre::Result<EthBundleHash> {
-        let params = serde_json::to_value(bundle)?;
-        let v = self.raw_call("mev_sendBundle", params).await?;
-        let hash: EthBundleHash =
-            serde_json::from_value(v.get("result").cloned().unwrap_or(serde_json::Value::Null))?;
-        Ok(hash)
+    pub async fn send_bundle(&self, bundle: &MevSendBundle) -> eyre::Result<EthBundleHash> {
+        self.raw_call("mev_sendBundle", &[bundle]).await
     }
 
     /// Simulate a bundle via `mev_simBundle`.
-    pub async fn simulate_bundle(&self, bundle: MevSendBundle) -> eyre::Result<()> {
-        let params = serde_json::to_value(bundle)?;
-        let v = self.raw_call("mev_simBundle", params).await?;
-        let resp: SimBundleResponse =
-            serde_json::from_value(v.get("result").cloned().unwrap_or(serde_json::Value::Null))?;
+    pub async fn simulate_bundle(&self, bundle: &MevSendBundle) -> eyre::Result<()> {
+        let resp: SimBundleResponse = self.raw_call("mev_simBundle", &[bundle]).await?;
         dbg!("successfully simulated bundle", &resp);
         Ok(())
     }
 
     /// Fetches the bundle status by hash
     pub async fn bundle_status(
         &self,
-        _hash: EthBundleHash,
+        hash: EthBundleHash,
         block_number: BlockNumber,
     ) -> eyre::Result<()> {
-        let params = json!({ "bundleHash": _hash, "blockNumber": block_number });
-        let _ = self.raw_call("flashbots_getBundleStatsV2", params).await?;
+        let params = json!({ "bundleHash": hash, "blockNumber": block_number });
+        let _resp: serde_json::Value =
+            self.raw_call("flashbots_getBundleStatsV2", &[params]).await?;
+
         Ok(())
     }
 
     /// Makes a raw JSON-RPC call with the Flashbots signature header to the method with the given params.
-    async fn raw_call(
+    async fn raw_call<Params: RpcSend, Payload: RpcRecv>(
         &self,
         method: &str,
-        params: serde_json::Value,
-    ) -> eyre::Result<serde_json::Value> {
-        let params = match params {
-            serde_json::Value::Array(_) => params,
-            other => serde_json::Value::Array(vec![other]),
-        };
-
-        let body = json!({"jsonrpc":"2.0","id":1,"method":method,"params":params});
-        let body_bz = serde_json::to_vec(&body)?;
+        params: &Params,
+    ) -> eyre::Result<Payload> {
+        let req = alloy::rpc::json_rpc::Request::new(
+            Cow::Owned(method.to_string()),
+            Id::Number(1),
+            params,
+        );
+        let body_bz = serde_json::to_vec(&req)?;
+        drop(req);
 
         let value = self.compute_signature(&body_bz).await?;
 
@@ -88,18 +87,19 @@ impl Flashbots {
             .send()
             .await?;
 
-        let text = resp.text().await?;
-        let v: serde_json::Value =
-            serde_json::from_str(&text).wrap_err("failed to parse flashbots JSON")?;
-        if let Some(err) = v.get("error") {
-            eyre::bail!("flashbots error: {err}");
+        let resp: Response<Payload> = resp.json().await?;
+
+        match resp.payload {
+            ResponsePayload::Success(payload) => Ok(payload),
+            ResponsePayload::Failure(err) => {
+                eyre::bail!("flashbots error: {err}");
+            }
         }
-        Ok(v)
     }
 
     /// Builds an EIP-191 signature for the given body bytes.
     async fn compute_signature(&self, body_bz: &[u8]) -> Result<String, eyre::Error> {
-        let payload = format!("0x{:x}", keccak256(body_bz));
+        let payload = keccak256(body_bz).to_string();
         let signature = self.signer.sign_message(payload.as_ref()).await?;
         dbg!(signature.to_string());
         let address = self.signer.address();

src/tasks/submit/flashbots/task.rs

@@ -236,15 +236,13 @@ impl FlashbotsTask {
             };
 
             // simulate the bundle against Flashbots then send the bundle
-            if let Err(err) =
-                flashbots.simulate_bundle(bundle.clone()).instrument(span.clone()).await
-            {
+            if let Err(err) = flashbots.simulate_bundle(&bundle).instrument(span.clone()).await {
                 span_scoped!(span, debug!(%err, "bundle simulation failed"));
                 continue;
             }
 
             let _ = flashbots
-                .send_bundle(bundle)
+                .send_bundle(&bundle)
                 .instrument(span.clone())
                 .await
                 .inspect(|bundle_hash| {

tests/flashbots_provider_test.rs

@@ -40,7 +40,7 @@ async fn test_simulate_valid_bundle_sepolia() {
     dbg!("submitting bundle with 1 tx", &bundle_body);
     let bundle = MevSendBundle::new(latest_block, Some(0), ProtocolVersion::V0_1, bundle_body);
 
-    flashbots.simulate_bundle(bundle).await.expect("failed to simulate bundle");
+    flashbots.simulate_bundle(&bundle).await.expect("failed to simulate bundle");
 }
 
 async fn get_test_provider() -> Flashbots {