diff --git a/nimbus/beacon/api_handler/api_forkchoice.nim b/nimbus/beacon/api_handler/api_forkchoice.nim
index ee77a1482c..24a06892f9 100644
--- a/nimbus/beacon/api_handler/api_forkchoice.nim
+++ b/nimbus/beacon/api_handler/api_forkchoice.nim
@@ -39,7 +39,7 @@ template validateVersion(attrsOpt, com, expectedVersion) =
         raise invalidParams("if timestamp is earlier than Shanghai," &
           " payloadAttributes must be PayloadAttributesV1")
 
-    if version != expectedVersion:
+    if expectedVersion == Version.V3 and version != expectedVersion:
       raise invalidParams("forkChoiceUpdated" & $expectedVersion &
       " expect PayloadAttributes" & $expectedVersion &
       " but got PayloadAttributes" & $version)
diff --git a/nimbus/beacon/api_handler/api_getpayload.nim b/nimbus/beacon/api_handler/api_getpayload.nim
index 5375ad77e0..45faa084c2 100644
--- a/nimbus/beacon/api_handler/api_getpayload.nim
+++ b/nimbus/beacon/api_handler/api_getpayload.nim
@@ -18,17 +18,25 @@ import
 
 {.push gcsafe, raises:[CatchableError].}
 
-proc getPayload*(ben: BeaconEngineRef, id: PayloadID): GetPayloadV2Response =
+proc getPayload*(ben: BeaconEngineRef,
+                 expectedVersion: Version,
+                 id: PayloadID): GetPayloadV2Response =
   trace "Engine API request received",
     meth = "GetPayload", id
 
-  var payload: ExecutionPayloadV1OrV2
+  var payloadGeneric: ExecutionPayload
   var blockValue: UInt256
-  if not ben.get(id, blockValue, payload):
+  if not ben.get(id, blockValue, payloadGeneric):
     raise unknownPayload("Unknown payload")
 
+  let version = payloadGeneric.version
+  if version > expectedVersion:
+    raise unsupportedFork("getPayload" & $expectedVersion &
+    " expect ExecutionPayload" & $expectedVersion &
+    " but get ExecutionPayload" & $version)
+
   GetPayloadV2Response(
-    executionPayload: payload,
+    executionPayload: payloadGeneric.V1V2,
     blockValue: blockValue
   )
 
@@ -36,11 +44,16 @@ proc getPayloadV3*(ben: BeaconEngineRef, id: PayloadID): GetPayloadV3Response =
   trace "Engine API request received",
     meth = "GetPayload", id
 
-  var payload: ExecutionPayloadV3
+  var payloadGeneric: ExecutionPayload
   var blockValue: UInt256
-  if not ben.get(id, blockValue, payload):
+  if not ben.get(id, blockValue, payloadGeneric):
     raise unknownPayload("Unknown payload")
 
+  let version = payloadGeneric.version
+  if version != Version.V3:
+    raise unsupportedFork("getPayloadV3 expect ExecutionPayloadV3 but get ExecutionPayload" & $version)
+
+  let payload = payloadGeneric.V3
   let com = ben.com
   if not com.isCancunOrLater(ethTime payload.timestamp):
     raise unsupportedFork("payload timestamp is less than Cancun activation")
diff --git a/nimbus/beacon/api_handler/api_newpayload.nim b/nimbus/beacon/api_handler/api_newpayload.nim
index f679aac513..7527f98fcf 100644
--- a/nimbus/beacon/api_handler/api_newpayload.nim
+++ b/nimbus/beacon/api_handler/api_newpayload.nim
@@ -38,7 +38,7 @@ template validateVersion(com, timestamp, version, expectedVersion) =
       raise invalidParams("if timestamp is earlier than Shanghai, " &
         "payload must be ExecutionPayloadV1")
 
-  if version != expectedVersion:
+  if expectedVersion == Version.V3 and version != expectedVersion:
     raise invalidParams("newPayload" & $expectedVersion &
     " expect ExecutionPayload" & $expectedVersion &
     " but got ExecutionPayload" & $version)
@@ -54,6 +54,10 @@ proc newPayload*(ben: BeaconEngineRef,
     number = payload.blockNumber,
     hash = payload.blockHash
 
+  if expectedVersion == Version.V3:
+    if beaconRoot.isNone:
+      raise invalidParams("newPayloadV3 expect beaconRoot but got none")
+
   let
     com = ben.com
     db  = com.db
diff --git a/nimbus/beacon/web3_eth_conv.nim b/nimbus/beacon/web3_eth_conv.nim
index 8c02bbc300..05b59102cf 100644
--- a/nimbus/beacon/web3_eth_conv.nim
+++ b/nimbus/beacon/web3_eth_conv.nim
@@ -71,6 +71,9 @@ func w3PrevRandao*(): Web3PrevRandao =
 func w3Address*(): Web3Address =
   discard
 
+func w3Hash*(): Web3Hash =
+  discard
+
 # ------------------------------------------------------------------------------
 # Web3 types to Eth types
 # ------------------------------------------------------------------------------
@@ -144,6 +147,19 @@ func ethTxs*(list: openArray[Web3Tx], removeBlobs = false):
 func w3Hash*(x: common.Hash256): Web3Hash =
   Web3Hash x.data
 
+func w3Hashes*(list: openArray[common.Hash256]): seq[Web3Hash] =
+  for x in list:
+    result.add Web3Hash x.data
+
+func w3Hashes*(z: Option[seq[common.Hash256]]): Option[seq[Web3Hash]] =
+  if z.isNone: none(seq[Web3Hash])
+  else:
+    let list = z.get
+    var v = newSeq[Web3Hash](list.len)
+    for x in list:
+      v.add Web3Hash x.data
+    some(v)
+
 func w3Hash*(x: Option[common.Hash256]): Option[BlockHash] =
   if x.isNone: none(BlockHash)
   else: some(BlockHash x.get.data)
diff --git a/nimbus/core/tx_pool/tx_tasks/tx_classify.nim b/nimbus/core/tx_pool/tx_tasks/tx_classify.nim
index 7460af04bf..6a5bb6872f 100644
--- a/nimbus/core/tx_pool/tx_tasks/tx_classify.nim
+++ b/nimbus/core/tx_pool/tx_tasks/tx_classify.nim
@@ -37,7 +37,13 @@ logScope:
 # ------------------------------------------------------------------------------
 
 proc checkTxBasic(xp: TxPoolRef; item: TxItemRef): bool =
-  let res = validateTxBasic(item.tx.removeNetworkPayload, xp.chain.nextFork)
+  let res = validateTxBasic(
+    item.tx.removeNetworkPayload,
+    xp.chain.nextFork,
+    # A new transaction of the next fork may be
+    # coming before the fork activated
+    validateFork = false
+  )
   if res.isOk:
     return true
   item.info = res.error
diff --git a/nimbus/core/validate.nim b/nimbus/core/validate.nim
index bd4257566b..1922366409 100644
--- a/nimbus/core/validate.nim
+++ b/nimbus/core/validate.nim
@@ -226,16 +226,18 @@ func gasCost*(tx: Transaction): UInt256 =
 
 proc validateTxBasic*(
     tx:       Transaction;     ## tx to validate
-    fork:     EVMFork): Result[void, string] =
-
-  if tx.txType == TxEip2930 and fork < FkBerlin:
-    return err("invalid tx: Eip2930 Tx type detected before Berlin")
-
-  if tx.txType == TxEip1559 and fork < FkLondon:
-    return err("invalid tx: Eip1559 Tx type detected before London")
-
-  if tx.txType == TxEip4844 and fork < FkCancun:
-    return err("invalid tx: Eip4844 Tx type detected before Cancun")
+    fork:     EVMFork,
+    validateFork: bool = true): Result[void, string] =
+
+  if validateFork:
+    if tx.txType == TxEip2930 and fork < FkBerlin:
+      return err("invalid tx: Eip2930 Tx type detected before Berlin")
+  
+    if tx.txType == TxEip1559 and fork < FkLondon:
+      return err("invalid tx: Eip1559 Tx type detected before London")
+  
+    if tx.txType == TxEip4844 and fork < FkCancun:
+      return err("invalid tx: Eip4844 Tx type detected before Cancun")
 
   if fork >= FkShanghai and tx.contractCreation and tx.payload.len > EIP3860_MAX_INITCODE_SIZE:
     return err("invalid tx: initcode size exceeds maximum")
diff --git a/nimbus/rpc/engine_api.nim b/nimbus/rpc/engine_api.nim
index b284d4866c..5d0a0300fb 100644
--- a/nimbus/rpc/engine_api.nim
+++ b/nimbus/rpc/engine_api.nim
@@ -15,7 +15,8 @@ import
   ../beacon/api_handler,
   ../beacon/beacon_engine,
   ../beacon/web3_eth_conv,
-  ../beacon/execution_types
+  ../beacon/execution_types,
+  ../beacon/api_handler/api_utils
 
 {.push raises: [].}
 
@@ -50,17 +51,19 @@ proc setupEngineAPI*(engine: BeaconEngineRef, server: RpcServer) =
     return engine.newPayload(Version.V2, payload)
 
   server.rpc("engine_newPayloadV3") do(payload: ExecutionPayload,
-                                       expectedBlobVersionedHashes: seq[Web3Hash],
-                                       parentBeaconBlockRoot: Web3Hash) -> PayloadStatusV1:
-    if not validateVersionedHashed(payload, expectedBlobVersionedHashes):
+                                       expectedBlobVersionedHashes: Option[seq[Web3Hash]],
+                                       parentBeaconBlockRoot: Option[Web3Hash]) -> PayloadStatusV1:
+    if expectedBlobVersionedHashes.isNone:
+      raise invalidParams("newPayloadV3 expect blobVersionedHashes but got none")
+    if not validateVersionedHashed(payload, expectedBlobVersionedHashes.get):
       return invalidStatus()
-    return engine.newPayload(Version.V3, payload, some(parentBeaconBlockRoot))
+    return engine.newPayload(Version.V3, payload, parentBeaconBlockRoot)
 
   server.rpc("engine_getPayloadV1") do(payloadId: PayloadID) -> ExecutionPayloadV1:
-    return engine.getPayload(payloadId).executionPayload.V1
+    return engine.getPayload(Version.V1, payloadId).executionPayload.V1
 
   server.rpc("engine_getPayloadV2") do(payloadId: PayloadID) -> GetPayloadV2Response:
-    return engine.getPayload(payloadId)
+    return engine.getPayload(Version.V2, payloadId)
 
   server.rpc("engine_getPayloadV3") do(payloadId: PayloadID) -> GetPayloadV3Response:
     return engine.getPayloadV3(payloadId)