grandinetech · hangleang · Mar 12, 2026
diff --git a/bindings/c/src/containers.rs b/bindings/c/src/containers.rs
@@ -6,8 +6,8 @@ use execution_engine::{
     BlobAndProofV1, BlobAndProofV2, BlobsBundleV1, BlobsBundleV2, EngineGetPayloadV2Response,
     EngineGetPayloadV3Response, EngineGetPayloadV4Response, EngineGetPayloadV5Response,
     ExecutionPayloadV1, ExecutionPayloadV2, ExecutionPayloadV3, ForkChoiceStateV1,
-    PayloadAttributesV1, PayloadAttributesV2, PayloadAttributesV3, PayloadStatusV1,
-    PayloadValidationStatus, RawExecutionRequests, RequestType, WithdrawalV1,
+    PayloadAttributesV1, PayloadAttributesV2, PayloadAttributesV3, PayloadAttributesV4,
+    PayloadStatusV1, PayloadValidationStatus, RawExecutionRequests, RequestType, WithdrawalV1,
 };
 use generic_array::ArrayLength;
 use ssz::{ByteVector, ContiguousList, ContiguousVector, SszReadDefault, SszWrite};
@@ -407,6 +407,30 @@ impl From<PayloadAttributesV3<Mainnet>> for CPayloadAttributesV3 {
     }
 }
 
+#[derive(Debug, Default)]
+#[repr(C)]
+pub struct CPayloadAttributesV4 {
+    timestamp: u64,
+    prev_randao: CH256,
+    suggested_fee_recipient: CH160,
+    withdrawals: CVec<CWithdrawalV1>,
+    parent_beacon_block_root: CH256,
+    slot_number: u64,
+}
+
+impl From<PayloadAttributesV4<Mainnet>> for CPayloadAttributesV4 {
+    fn from(value: PayloadAttributesV4<Mainnet>) -> Self {
+        Self {
+            timestamp: value.timestamp,
+            prev_randao: value.prev_randao.into(),
+            suggested_fee_recipient: value.suggested_fee_recipient.into(),
+            withdrawals: value.withdrawals.into_iter().map(Into::into).collect(),
+            parent_beacon_block_root: value.parent_beacon_block_root.into(),
+            slot_number: value.slot_number,
+        }
+    }
+}
+
 #[derive(Debug)]
 #[repr(C)]
 #[allow(unused, reason = "constructed from the C side of bindings")]

diff --git a/bindings/c/src/lib.rs b/bindings/c/src/lib.rs
@@ -11,7 +11,8 @@ use execution_engine::{
     BlobAndProofV1, EngineGetPayloadV1Response, EngineGetPayloadV2Response,
     EngineGetPayloadV3Response, EngineGetPayloadV4Response, EngineGetPayloadV5Response,
     ExecutionPayloadV1, ExecutionPayloadV2, ExecutionPayloadV3, ForkChoiceStateV1,
-    PayloadAttributesV1, PayloadAttributesV2, PayloadAttributesV3, PayloadStatusV1,
+    PayloadAttributesV1, PayloadAttributesV2, PayloadAttributesV3, PayloadAttributesV4,
+    PayloadStatusV1,
 };
 use runtime::{grandine_args::GrandineArgs, run, shutdown};
 use tracing::error;
@@ -28,7 +29,7 @@ use crate::{
         CEngineGetPayloadV3Response, CEngineGetPayloadV4Response, CEngineGetPayloadV5Response,
         CExecutionPayloadV1, CExecutionPayloadV2, CExecutionPayloadV3, CExecutionRequests,
         CForkChoiceStateV1, CForkChoiceUpdatedResponse, CPayloadAttributesV1, CPayloadAttributesV2,
-        CPayloadAttributesV3, CPayloadStatusV1,
+        CPayloadAttributesV3, CPayloadAttributesV4, CPayloadStatusV1,
     },
     generic::{CGrandineString, COption, CResult, CVec, GRANDINE_ERROR_GENERIC},
     layout::{CLayout, repeat_layout},
@@ -68,6 +69,10 @@ pub struct CEmbedAdapter {
         state: CForkChoiceStateV1,
         payload: COption<CPayloadAttributesV3>,
     ) -> CResult<CForkChoiceUpdatedResponse>,
+    engine_forkchoice_updated_v4: unsafe extern "C" fn(
+        state: CForkChoiceStateV1,
+        payload: COption<CPayloadAttributesV4>,
+    ) -> CResult<CForkChoiceUpdatedResponse>,
     engine_get_payload_v1: unsafe extern "C" fn(payload_id: CH64) -> CResult<CExecutionPayloadV1>,
     engine_get_payload_v2:
         unsafe extern "C" fn(payload_id: CH64) -> CResult<CEngineGetPayloadV2Response>,
@@ -214,6 +219,19 @@ impl eth1_api::EmbedAdapter for CEmbedAdapter {
         Result::<_>::from(result).map(Into::into)
     }
 
+    fn engine_forkchoice_updated_v4(
+        &self,
+        state: ForkChoiceStateV1,
+        payload: Option<PayloadAttributesV4<types::preset::Mainnet>>,
+    ) -> Result<eth1_api::RawForkChoiceUpdatedResponse> {
+        let state: CForkChoiceStateV1 = state.into();
+        let payload: Option<CPayloadAttributesV4> = payload.map(Into::into);
+        let payload = payload.into();
+        let result = unsafe { (self.engine_forkchoice_updated_v4)(state, payload) };
+
+        Result::<_>::from(result).map(Into::into)
+    }
+
     fn engine_get_payload_v1(
         &self,
         payload_id: web3::types::H64,

diff --git a/bindings/csharp/Grandine.NethermindPlugin/GrandineClient.cs b/bindings/csharp/Grandine.NethermindPlugin/GrandineClient.cs
@@ -27,6 +27,9 @@
 [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
 internal delegate CResult_CForkChoiceUpdatedResponse EngineForkchoiceUpdatedV3Delegate(CForkChoiceStateV1 state, COption_CPayloadAttributesV3 attributes);
 
+[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
+internal delegate CResult_CForkChoiceUpdatedResponse EngineForkchoiceUpdatedV4Delegate(CForkChoiceStateV1 state, COption_CPayloadAttributesV4 attributes);
+
 [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
 internal delegate CResult_CExecutionPayloadV1 EngineGetPayloadV1Delegate(CH64 payloadId);
 
@@ -65,6 +68,7 @@ public class GrandineClient : IAsyncDisposable
     private readonly EngineForkchoiceUpdatedV1Delegate engineForkchoiceUpdatedV1;
     private readonly EngineForkchoiceUpdatedV2Delegate engineForkchoiceUpdatedV2;
     private readonly EngineForkchoiceUpdatedV3Delegate engineForkchoiceUpdatedV3;
+    private readonly EngineForkchoiceUpdatedV4Delegate engineForkchoiceUpdatedV4;
     private readonly EngineGetPayloadV1Delegate engineGetPayloadV1;
     private readonly EngineGetPayloadV2Delegate engineGetPayloadV2;
     private readonly EngineGetPayloadV3Delegate engineGetPayloadV3;
@@ -97,6 +101,7 @@ public GrandineClient(IGrandineEngineApi engineApi)
             this.engineForkchoiceUpdatedV1 = this.engineApi.EngineForkchoiceUpdatedV1;
             this.engineForkchoiceUpdatedV2 = this.engineApi.EngineForkchoiceUpdatedV2;
             this.engineForkchoiceUpdatedV3 = this.engineApi.EngineForkchoiceUpdatedV3;
+            this.engineForkchoiceUpdatedV4 = this.engineApi.EngineForkchoiceUpdatedV4;
             this.engineGetPayloadV1 = this.engineApi.EngineGetPayloadV1;
             this.engineGetPayloadV2 = this.engineApi.EngineGetPayloadV2;
             this.engineGetPayloadV3 = this.engineApi.EngineGetPayloadV3;
@@ -113,6 +118,7 @@ public GrandineClient(IGrandineEngineApi engineApi)
             IntPtr engine_forkchoiceUpdatedV1Ptr = Marshal.GetFunctionPointerForDelegate(this.engineForkchoiceUpdatedV1);
             IntPtr engine_forkchoiceUpdatedV2Ptr = Marshal.GetFunctionPointerForDelegate(this.engineForkchoiceUpdatedV2);
             IntPtr engine_forkchoiceUpdatedV3Ptr = Marshal.GetFunctionPointerForDelegate(this.engineForkchoiceUpdatedV3);
+            IntPtr engine_forkchoiceUpdatedV4Ptr = Marshal.GetFunctionPointerForDelegate(this.engineForkchoiceUpdatedV4);
             IntPtr engine_getPayloadV1Ptr = Marshal.GetFunctionPointerForDelegate(this.engineGetPayloadV1);
             IntPtr engine_getPayloadV2Ptr = Marshal.GetFunctionPointerForDelegate(this.engineGetPayloadV2);
             IntPtr engine_getPayloadV3Ptr = Marshal.GetFunctionPointerForDelegate(this.engineGetPayloadV3);
@@ -131,6 +137,7 @@ public GrandineClient(IGrandineEngineApi engineApi)
                 engine_forkchoice_updated_v1 = (delegate* unmanaged[Cdecl]<CForkChoiceStateV1, COption_CPayloadAttributesV1, CResult_CForkChoiceUpdatedResponse>)engine_forkchoiceUpdatedV1Ptr,
                 engine_forkchoice_updated_v2 = (delegate* unmanaged[Cdecl]<CForkChoiceStateV1, COption_CPayloadAttributesV2, CResult_CForkChoiceUpdatedResponse>)engine_forkchoiceUpdatedV2Ptr,
                 engine_forkchoice_updated_v3 = (delegate* unmanaged[Cdecl]<CForkChoiceStateV1, COption_CPayloadAttributesV3, CResult_CForkChoiceUpdatedResponse>)engine_forkchoiceUpdatedV3Ptr,
+                engine_forkchoice_updated_v4 = (delegate* unmanaged[Cdecl]<CForkChoiceStateV1, COption_CPayloadAttributesV4, CResult_CForkChoiceUpdatedResponse>)engine_forkchoiceUpdatedV4Ptr,
                 engine_get_payload_v1 = (delegate* unmanaged[Cdecl]<CH64, CResult_CExecutionPayloadV1>)engine_getPayloadV1Ptr,
                 engine_get_payload_v2 = (delegate* unmanaged[Cdecl]<CH64, CResult_CEngineGetPayloadV2Response>)engine_getPayloadV2Ptr,
                 engine_get_payload_v3 = (delegate* unmanaged[Cdecl]<CH64, CResult_CEngineGetPayloadV3Response>)engine_getPayloadV3Ptr,

diff --git a/bindings/csharp/Grandine.NethermindPlugin/GrandineEngineApi.cs b/bindings/csharp/Grandine.NethermindPlugin/GrandineEngineApi.cs
@@ -255,6 +255,27 @@ public CResult_CForkChoiceUpdatedResponse EngineForkchoiceUpdatedV3(CForkChoiceS
         }
     }
 
+    public CResult_CForkChoiceUpdatedResponse EngineForkchoiceUpdatedV4(CForkChoiceStateV1 state, COption_CPayloadAttributesV4 payload)
+    {
+        this.logger.Debug("Received engine_forkchoiceUpdatedV4 request from grandine");
+
+        try
+        {
+            var forkchoiceUpdatedResult = this.engineRpc.engine_forkchoiceUpdatedV4(
+                state.ToForkchoiceStateV1(),
+                GrandineUtils.ConvertPayloadAttributes(payload)).Result;
+
+            return forkchoiceUpdatedResult.Result != Result.Success
+                ? CResult_CForkChoiceUpdatedResponse.Fail(NativeMethods.GRANDINE_ERROR_ENGINE_API, forkchoiceUpdatedResult.Result.Error)
+                : CResult_CForkChoiceUpdatedResponse.Success(new CForkChoiceUpdatedResponse(forkchoiceUpdatedResult.Data));
+        }
+        catch (Exception e)
+        {
+            this.logger.Error("Unexpected exception occurred during engine_forkchoiceUpdatedV4 function invocation", e);
+            return CResult_CForkChoiceUpdatedResponse.Fail(NativeMethods.GRANDINE_ERROR_GENERIC, e.Message);
+        }
+    }
+
     public CResult_CExecutionPayloadV1 EngineGetPayloadV1(CH64 payloadId)
     {
         this.logger.Debug("Received engine_getPayloadV1 request from grandine");

diff --git a/bindings/csharp/Grandine.NethermindPlugin/GrandineUtils.cs b/bindings/csharp/Grandine.NethermindPlugin/GrandineUtils.cs
@@ -251,6 +251,24 @@ public static CPayloadValidationStatus ConvertPayloadValidationStatus(string sta
         };
     }
 
+    public static PayloadAttributes? ConvertPayloadAttributes(COption_CPayloadAttributesV4 attr)
+    {
+        if (!attr.is_something)
+        {
+            return null;
+        }
+
+        return new PayloadAttributes
+        {
+            Timestamp = attr.value.timestamp,
+            PrevRandao = attr.value.prev_randao.ToHash256(),
+            SuggestedFeeRecipient = attr.value.suggested_fee_recipient.ToAddress(),
+            Withdrawals = WithdrawalsFromNative(attr.value.withdrawals),
+            ParentBeaconBlockRoot = attr.value.parent_beacon_block_root.ToHash256(),
+            SlotNumber = attr.value.slot_number,
+        };
+    }
+
     public static IEnumerable<string> ConvertCapabilities(CVec_CGrandineString capabilities)
     {
         var span = capabilities.AsSpan();

diff --git a/bindings/csharp/Grandine.NethermindPlugin/IGrandineEngineApi.cs b/bindings/csharp/Grandine.NethermindPlugin/IGrandineEngineApi.cs
@@ -18,6 +18,8 @@ public interface IGrandineEngineApi
 
     CResult_CForkChoiceUpdatedResponse EngineForkchoiceUpdatedV3(CForkChoiceStateV1 state, COption_CPayloadAttributesV3 payload);
 
+    CResult_CForkChoiceUpdatedResponse EngineForkchoiceUpdatedV4(CForkChoiceStateV1 state, COption_CPayloadAttributesV4 payload);
+
     CResult_CExecutionPayloadV1 EngineGetPayloadV1(CH64 payloadId);
 
     CResult_CEngineGetPayloadV2Response EngineGetPayloadV2(CH64 payloadId);

diff --git a/block_producer/src/block_producer.rs b/block_producer/src/block_producer.rs
@@ -12,7 +12,7 @@ use dedicated_executor::{DedicatedExecutor, Job};
 use eth1_api::{ApiController, ClientVersions, Eth1ExecutionEngine, WithClientVersions};
 use execution_engine::{
     ExecutionEngine as _, PayloadAttributes, PayloadAttributesV1, PayloadAttributesV2,
-    PayloadAttributesV3, PayloadId,
+    PayloadAttributesV3, PayloadAttributesV4, PayloadId,
 };
 use features::Feature;
 use fork_choice_control::Wait;
@@ -1627,12 +1627,13 @@ impl<P: Preset, W: Wait> BlockBuildContext<P, W> {
                 let parent_beacon_block_root =
                     accessors::get_block_root_at_slot(state, state.slot().saturating_sub(1))?;
 
-                PayloadAttributes::Gloas(PayloadAttributesV3 {
+                PayloadAttributes::Gloas(PayloadAttributesV4 {
                     timestamp,
                     prev_randao,
                     suggested_fee_recipient,
                     withdrawals,
                     parent_beacon_block_root,
+                    slot_number: state.slot(),
                 })
             }
         };

diff --git a/eth1_api/src/eth1_api/embed_api.rs b/eth1_api/src/eth1_api/embed_api.rs
@@ -9,7 +9,7 @@ use execution_engine::{
     EngineGetPayloadV3Response, EngineGetPayloadV4Response, EngineGetPayloadV5Response,
     ExecutionPayloadV1, ExecutionPayloadV2, ExecutionPayloadV3, ForkChoiceStateV1,
     ForkChoiceUpdatedResponse, PayloadAttributes, PayloadAttributesV1, PayloadAttributesV2,
-    PayloadAttributesV3, PayloadId, PayloadStatusV1,
+    PayloadAttributesV3, PayloadAttributesV4, PayloadId, PayloadStatusV1,
 };
 use futures::channel::mpsc::UnboundedSender;
 use prometheus_metrics::Metrics;
@@ -41,9 +41,10 @@ use crate::{
     deposit_event::DepositEvent,
     eth1_api::{
         ENGINE_FORKCHOICE_UPDATED_V1, ENGINE_FORKCHOICE_UPDATED_V2, ENGINE_FORKCHOICE_UPDATED_V3,
-        ENGINE_GET_EL_BLOBS_V1, ENGINE_GET_EL_BLOBS_V2, ENGINE_GET_PAYLOAD_V1,
-        ENGINE_GET_PAYLOAD_V2, ENGINE_GET_PAYLOAD_V3, ENGINE_GET_PAYLOAD_V4, ENGINE_GET_PAYLOAD_V5,
-        ENGINE_NEW_PAYLOAD_V1, ENGINE_NEW_PAYLOAD_V2, ENGINE_NEW_PAYLOAD_V3, ENGINE_NEW_PAYLOAD_V4,
+        ENGINE_FORKCHOICE_UPDATED_V4, ENGINE_GET_EL_BLOBS_V1, ENGINE_GET_EL_BLOBS_V2,
+        ENGINE_GET_PAYLOAD_V1, ENGINE_GET_PAYLOAD_V2, ENGINE_GET_PAYLOAD_V3, ENGINE_GET_PAYLOAD_V4,
+        ENGINE_GET_PAYLOAD_V5, ENGINE_NEW_PAYLOAD_V1, ENGINE_NEW_PAYLOAD_V2, ENGINE_NEW_PAYLOAD_V3,
+        ENGINE_NEW_PAYLOAD_V4,
     },
     eth1_block::Eth1Block,
 };
@@ -98,6 +99,11 @@ pub trait EmbedAdapter: Send + Sync {
         state: ForkChoiceStateV1,
         payload: Option<PayloadAttributesV3<Mainnet>>,
     ) -> Result<RawForkChoiceUpdatedResponse>;
+    fn engine_forkchoice_updated_v4(
+        &self,
+        state: ForkChoiceStateV1,
+        payload: Option<PayloadAttributesV4<Mainnet>>,
+    ) -> Result<RawForkChoiceUpdatedResponse>;
 
     fn engine_get_payload_v1(&self, payload_id: H64)
     -> Result<EngineGetPayloadV1Response<Mainnet>>;
@@ -451,14 +457,15 @@ impl Eth1Api {
         }
     }
 
-    /// Calls [`engine_forkchoiceUpdatedV1`] or [`engine_forkchoiceUpdatedV2`] or [`engine_forkchoiceUpdatedV3`] depending on `payload_attributes`.
+    /// Calls [`engine_forkchoiceUpdatedV1`] or [`engine_forkchoiceUpdatedV2`] or [`engine_forkchoiceUpdatedV3`] or [`engine_forkchoiceUpdatedV4`] depending on `payload_attributes`.
     ///
     /// Later versions of `engine_forkchoiceUpdated` accept parameters of all prior versions,
     /// but using the earlier versions allows the application to work with old execution clients.
     ///
     /// [`engine_forkchoiceUpdatedV1`]: https://github.com/ethereum/execution-apis/blob/b7c5d3420e00648f456744d121ffbd929862924d/src/engine/paris.md#engine_forkchoiceupdatedv1
     /// [`engine_forkchoiceUpdatedV2`]: https://github.com/ethereum/execution-apis/blob/b7c5d3420e00648f456744d121ffbd929862924d/src/engine/shanghai.md#engine_forkchoiceupdatedv2
     /// [`engine_forkchoiceUpdatedV3`]: https://github.com/ethereum/execution-apis/blob/a0d03086564ab1838b462befbc083f873dcf0c0f/src/engine/cancun.md#engine_forkchoiceupdatedv3
+    /// [`engine_forkchoiceUpdatedV4`]: https://github.com/ethereum/execution-apis/blob/ffe6c839567f931ece3276d8242963744f09bf67/src/engine/amsterdam.md#engine_forkchoiceupdatedv4
     pub async fn forkchoice_updated<P: Preset>(
         &self,
         head_block_hash: ExecutionBlockHash,
@@ -507,8 +514,7 @@ impl Eth1Api {
                             Err(Error::InvalidParameters)
                         }
                     })
-                    .transpose()?
-                    .clone();
+                    .transpose()?;
 
                 self.exec(move |adapter| {
                     adapter.engine_forkchoice_updated_v1(fork_choice_state, payload_attributes)
@@ -531,15 +537,14 @@ impl Eth1Api {
                             Err(Error::InvalidParameters)
                         }
                     })
-                    .transpose()?
-                    .clone();
+                    .transpose()?;
 
                 self.exec(move |adapter| {
                     adapter.engine_forkchoice_updated_v2(fork_choice_state, payload_attributes)
                 })
                 .await?
             }
-            Phase::Deneb | Phase::Electra | Phase::Fulu | Phase::Gloas => {
+            Phase::Deneb | Phase::Electra | Phase::Fulu => {
                 let _timer = self.metrics.as_ref().map(|metrics| {
                     prometheus_metrics::start_timer_vec(
                         &metrics.eth1_api_request_times,
@@ -551,22 +556,43 @@ impl Eth1Api {
                     .map(|value| {
                         if let PayloadAttributes::Deneb(value)
                         | PayloadAttributes::Electra(value)
-                        | PayloadAttributes::Fulu(value)
-                        | PayloadAttributes::Gloas(value) = value
+                        | PayloadAttributes::Fulu(value) = value
                         {
                             Ok(value)
                         } else {
                             Err(Error::InvalidParameters)
                         }
                     })
-                    .transpose()?
-                    .clone();
+                    .transpose()?;
 
                 self.exec(move |adapter| {
                     adapter.engine_forkchoice_updated_v3(fork_choice_state, payload_attributes)
                 })
                 .await?
             }
+            Phase::Gloas => {
+                let _timer = self.metrics.as_ref().map(|metrics| {
+                    prometheus_metrics::start_timer_vec(
+                        &metrics.eth1_api_request_times,
+                        ENGINE_FORKCHOICE_UPDATED_V4,
+                    )
+                });
+
+                let payload_attributes = payload_attributes
+                    .map(|value| {
+                        if let PayloadAttributes::Gloas(value) = value {
+                            Ok(value)
+                        } else {
+                            Err(Error::InvalidParameters)
+                        }
+                    })
+                    .transpose()?;
+
+                self.exec(move |adapter| {
+                    adapter.engine_forkchoice_updated_v4(fork_choice_state, payload_attributes)
+                })
+                .await?
+            }
             _ => {
                 // This match arm will silently match any new phases.
                 // Cause a compilation error if a new phase is added.