diff --git a/packages/beacon-node/src/execution/engine/http.ts b/packages/beacon-node/src/execution/engine/http.ts
index 0d2656ae46e..58acec5018b 100644
--- a/packages/beacon-node/src/execution/engine/http.ts
+++ b/packages/beacon-node/src/execution/engine/http.ts
@@ -24,6 +24,7 @@ import {
   ExecutionEngineState,
   ExecutionPayloadStatus,
   IExecutionEngine,
+  InclusionList,
   PayloadAttributes,
   PayloadId,
   VersionedHashes,
@@ -202,10 +203,13 @@ export class ExecutionEngineHttp implements IExecutionEngine {
     executionPayload: ExecutionPayload,
     versionedHashes?: VersionedHashes,
     parentBlockRoot?: Root,
-    executionRequests?: ExecutionRequests
+    executionRequests?: ExecutionRequests,
+    inclusionList?: InclusionList,  // TODO FOCIL: figure out how to get IL when process_execution_payload
   ): Promise<ExecutePayloadResponse> {
     const method =
-      ForkSeq[fork] >= ForkSeq.electra
+      ForkSeq[fork] >= ForkSeq.focil
+        ? "engine_newPayloadV5"
+        : ForkSeq[fork] >= ForkSeq.electra
         ? "engine_newPayloadV4"
         : ForkSeq[fork] >= ForkSeq.deneb
           ? "engine_newPayloadV3"
@@ -215,6 +219,7 @@ export class ExecutionEngineHttp implements IExecutionEngine {
 
     const serializedExecutionPayload = serializeExecutionPayload(fork, executionPayload);
 
+    // TODO FOCIL: Add V5. Current code is ugly with all the nested if
     let engineRequest: EngineRequest;
     if (ForkSeq[fork] >= ForkSeq.deneb) {
       if (versionedHashes === undefined) {
diff --git a/packages/beacon-node/src/execution/engine/interface.ts b/packages/beacon-node/src/execution/engine/interface.ts
index c32cc1bc721..df6017f1151 100644
--- a/packages/beacon-node/src/execution/engine/interface.ts
+++ b/packages/beacon-node/src/execution/engine/interface.ts
@@ -109,6 +109,10 @@ export type ClientVersion = {
 
 export type VersionedHashes = Uint8Array[];
 
+export type InclusionList = {
+  transactions: Uint8Array[];
+}
+
 /**
  * Execution engine represents an abstract protocol to interact with execution clients. Potential transports include:
  * - JSON RPC over network
@@ -135,7 +139,8 @@ export interface IExecutionEngine {
     executionPayload: ExecutionPayload,
     versionedHashes?: VersionedHashes,
     parentBeaconBlockRoot?: Root,
-    executionRequests?: ExecutionRequests
+    executionRequests?: ExecutionRequests,
+    inclusionList?: InclusionList,
   ): Promise<ExecutePayloadResponse>;
 
   /**
diff --git a/packages/beacon-node/src/execution/engine/mock.ts b/packages/beacon-node/src/execution/engine/mock.ts
index 8a84d2b0148..f85ea93e4cb 100644
--- a/packages/beacon-node/src/execution/engine/mock.ts
+++ b/packages/beacon-node/src/execution/engine/mock.ts
@@ -89,6 +89,7 @@ export class ExecutionEngineMockBackend implements JsonRpcBackend {
       engine_newPayloadV2: this.notifyNewPayload.bind(this),
       engine_newPayloadV3: this.notifyNewPayload.bind(this),
       engine_newPayloadV4: this.notifyNewPayload.bind(this),
+      engine_newPayloadV5: this.notifyNewPayload.bind(this),
       engine_forkchoiceUpdatedV1: this.notifyForkchoiceUpdate.bind(this),
       engine_forkchoiceUpdatedV2: this.notifyForkchoiceUpdate.bind(this),
       engine_forkchoiceUpdatedV3: this.notifyForkchoiceUpdate.bind(this),
@@ -100,6 +101,8 @@ export class ExecutionEngineMockBackend implements JsonRpcBackend {
       engine_getPayloadBodiesByRangeV1: this.getPayloadBodiesByRange.bind(this),
       engine_getClientVersionV1: this.getClientVersionV1.bind(this),
       engine_getBlobsV1: this.getBlobs.bind(this),
+      engine_getInclusionListV1: () => ({transactions: []}),
+      engine_updatePayloadWithInclusionListV1: () => ({payloadId: ""})
     };
   }
 
diff --git a/packages/beacon-node/src/execution/engine/types.ts b/packages/beacon-node/src/execution/engine/types.ts
index f35a63aa3d9..22826ef9cb7 100644
--- a/packages/beacon-node/src/execution/engine/types.ts
+++ b/packages/beacon-node/src/execution/engine/types.ts
@@ -28,6 +28,7 @@ export type EngineApiRpcParamTypes = {
   engine_newPayloadV2: [ExecutionPayloadRpc];
   engine_newPayloadV3: [ExecutionPayloadRpc, VersionedHashesRpc, DATA];
   engine_newPayloadV4: [ExecutionPayloadRpc, VersionedHashesRpc, DATA, ExecutionRequestsRpc];
+  engine_newPayloadV5: [ExecutionPayloadRpc, VersionedHashesRpc, DATA, ExecutionRequestsRpc, InclusionListRpc];
   /**
    * 1. Object - Payload validity status with respect to the consensus rules:
    *   - blockHash: DATA, 32 Bytes - block hash value of the payload
@@ -70,6 +71,17 @@ export type EngineApiRpcParamTypes = {
   engine_getClientVersionV1: [ClientVersionRpc];
 
   engine_getBlobsV1: [DATA[]];
+
+  /**
+   * 1. DATA - 32 bytes - parent hash which returned inclusion list should be built upon
+   */
+  engine_getInclusionListV1: [DATA];
+
+  /**
+   * 1. DATA - 8 bytes - Identifier of the payload build process
+   * 2. DATA[] aka InclusionListV1
+   */
+  engine_updatePayloadWithInclusionListV1: [QUANTITY, InclusionListRpc];
 };
 
 export type PayloadStatus = {
@@ -87,6 +99,7 @@ export type EngineApiRpcReturnTypes = {
   engine_newPayloadV2: PayloadStatus;
   engine_newPayloadV3: PayloadStatus;
   engine_newPayloadV4: PayloadStatus;
+  engine_newPayloadV5: PayloadStatus;
   engine_forkchoiceUpdatedV1: {
     payloadStatus: PayloadStatus;
     payloadId: QUANTITY | null;
@@ -114,6 +127,10 @@ export type EngineApiRpcReturnTypes = {
   engine_getClientVersionV1: ClientVersionRpc[];
 
   engine_getBlobsV1: (BlobAndProofRpc | null)[];
+
+  engine_getInclusionListV1: InclusionListRpc;
+
+  engine_updatePayloadWithInclusionListV1: UpdateInclusionListResponse;
 };
 
 type ExecutionPayloadRpcWithValue = {
@@ -212,6 +229,16 @@ export interface BlobsBundleRpc {
   proofs: DATA[]; // some ELs could also provide proofs, each 48 bytes
 }
 
+type InclusionListRpc = {
+  /** Array of DATA - Array of transaction objects */
+  transactions: DATA[];
+}
+
+type UpdateInclusionListResponse = {
+  /** DATA, 8 Bytes - Identifier of the payload build process */
+  payloadId: QUANTITY;
+}
+
 export function serializeExecutionPayload(fork: ForkName, data: ExecutionPayload): ExecutionPayloadRpc {
   const payload: ExecutionPayloadRpc = {
     parentHash: bytesToData(data.parentHash),
diff --git a/packages/types/src/types.ts b/packages/types/src/types.ts
index 3f3105a6c96..042be9cd0d6 100644
--- a/packages/types/src/types.ts
+++ b/packages/types/src/types.ts
@@ -12,6 +12,7 @@ import {ts as bellatrix} from "./bellatrix/index.js";
 import {ts as capella} from "./capella/index.js";
 import {ts as deneb} from "./deneb/index.js";
 import {ts as electra} from "./electra/index.js";
+import {ts as focil} from "./focil/index.js";
 import {ts as phase0} from "./phase0/index.js";
 import {Slot} from "./primitive/types.js";
 
@@ -22,6 +23,7 @@ export {ts as bellatrix} from "./bellatrix/index.js";
 export {ts as capella} from "./capella/index.js";
 export {ts as deneb} from "./deneb/index.js";
 export {ts as electra} from "./electra/index.js";
+export {ts as focil} from "./focil/index.js";
 
 /** Common non-spec type to represent roots as strings */
 export type RootHex = string;