feat: add jsonrpsee trait for SuperchainSignal (#217)

related issues  paradigmxyz/reth#12275
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## Motivation

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## Solution

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## PR Checklist

- [ ] Added Tests
- [ ] Added Documentation
- [ ] Breaking changes

---------

Co-authored-by: Matthias Seitz <[email protected]>

crates/rpc-jsonrpsee/Cargo.toml

@@ -17,6 +17,7 @@ workspace = true
 [dependencies]
 # Alloy
 op-alloy-rpc-types.workspace = true
+op-alloy-rpc-types-engine = { workspace = true, features = ["serde"] }
 alloy-eips.workspace = true
 alloy-primitives.workspace = true
 

crates/rpc-jsonrpsee/src/traits.rs

@@ -12,6 +12,7 @@ use op_alloy_rpc_types::{
     safe_head::SafeHeadResponse,
     sync::SyncStatus,
 };
+use op_alloy_rpc_types_engine::{ProtocolVersion, SuperchainSignal};
 use std::net::IpAddr;
 
 /// Optimism specified rpc interface.
@@ -120,3 +121,21 @@ pub trait OpAdminApi {
     #[method(name = "sequencerActive")]
     async fn admin_sequencer_active(&self) -> RpcResult<bool>;
 }
+
+/// Engine API extension for Optimism superchain signaling
+#[cfg_attr(not(feature = "client"), rpc(server, namespace = "engine"))]
+#[cfg_attr(feature = "client", rpc(server, client, namespace = "engine"))]
+pub trait EngineApiExt {
+    /// Signal superchain v1 message
+    ///
+    /// The execution engine SHOULD warn when the recommended version is newer than the current
+    /// version. The execution engine SHOULD take safety precautions if it does not meet
+    /// the required version.
+    ///
+    /// # Returns
+    /// The latest supported OP-Stack protocol version of the execution engine.
+    ///
+    /// See: <https://specs.optimism.io/protocol/exec-engine.html#engine_signalsuperchainv1>
+    #[method(name = "signalSuperchainV1")]
+    async fn signal_superchain_v1(&self, signal: SuperchainSignal) -> RpcResult<ProtocolVersion>;
+}