diff --git a/hive_integration/nodocker/engine/base_spec.nim b/hive_integration/nodocker/engine/base_spec.nim
new file mode 100644
index 000000000..be502a018
--- /dev/null
+++ b/hive_integration/nodocker/engine/base_spec.nim
@@ -0,0 +1,70 @@
+import
+  std/[options],
+  eth/common,
+  ./clmock,
+  ./types,
+  ../../../tools/common/helpers,
+  ../../../nimbus/common/chain_config
+
+func getBlockTimeIncrements*(s: BaseSpec): int =
+  if s.blockTimestampIncrement == 0:
+    return 1
+  return s.blockTimestampIncrement
+
+proc configureCLMock*(s: BaseSpec, cl: CLMocker) =
+  if s.slotsToSafe != 0:
+    cl.slotsToSafe = s.slotsToSafe
+
+  if s.slotsToFinalized != 0:
+    cl.slotsToFinalized = s.slotsToFinalized
+
+  if s.safeSlotsToImportOptimistically != 0:
+    cl.safeSlotsToImportOptimistically = s.safeSlotsToImportOptimistically
+
+  cl.blockTimestampIncrement = some(s.getBlockTimeIncrements())
+
+func getMainFork*(s: BaseSpec): string =
+  let mainFork = s.mainFork
+  if mainFork == "":
+    return ForkParis
+  return mainFork
+
+func getGenesisTimestamp*(s: BaseSpec): uint64 =
+  var genesisTimestamp = GenesisTimestamp
+  if s.genesisTimestamp != 0:
+    genesisTimestamp = s.genesisTimestamp
+  return genesisTimestamp.uint64
+
+func getBlockTime*(s: BaseSpec, blockNumber: uint64): uint64 =
+  return s.getGenesisTimestamp() + blockNumber*s.getBlockTimeIncrements().uint64
+
+func getForkTime*(s: BaseSpec): uint64 =
+  var forkTime = s.forkTime
+  if s.forkHeight > 0:
+    forkTime = s.getBlockTime(s.forkHeight.uint64)
+  return forkTime
+
+func getForkConfig*(s: BaseSpec): ChainConfig =
+  let
+    forkTime = s.getForkTime()
+    previousForkTime = s.previousForkTime
+    mainFork = s.getMainFork()
+    forkConfig = getChainConfig(mainFork)
+    genesisTimestamp = s.getGenesisTimestamp()
+
+  doAssert(previousForkTime <= forkTime,
+    "previous fork time cannot be greater than fork time")
+
+  if mainFork == ForkParis:
+    let cond = forkTime > genesisTimestamp or previousForkTime != 0
+    doAssert(not cond, "Cannot configure a fork before Paris, skip test")
+  elif mainFork == ForkShanghai:
+    doAssert(previousForkTime == 0, "Cannot configure a fork before Shanghai")
+    forkConfig.shanghaiTime = some(forkTime.EthTime)
+  elif mainFork == ForkCancun:
+    forkConfig.shanghaiTime = some(previousForkTime.EthTime)
+    forkConfig.cancunTime = some(forkTime.EthTime)
+  else:
+    doAssert(false, "unknown fork: " & mainFork)
+
+  return forkConfig
diff --git a/hive_integration/nodocker/engine/cancun/blobs.nim b/hive_integration/nodocker/engine/cancun/blobs.nim
new file mode 100644
index 000000000..1e59b962c
--- /dev/null
+++ b/hive_integration/nodocker/engine/cancun/blobs.nim
@@ -0,0 +1,144 @@
+import
+  eth/common/eth_types,
+  stint,
+  kzg4844/kzg_ex as kzg,
+  stew/endians2,
+  nimcrypto/sha2,
+  stew/results,
+  ../../../nimbus/core/eip4844
+
+type
+  BlobID* = uint64
+  BlobIDs* = seq[BlobID]
+
+  BlobCommitment* = object
+    blob*: kzg.KzgBlob
+    commitment*: kzg.KZGCommitment
+
+  BlobTxWrapData* = object
+    hashes*: seq[Hash256]
+    blobs*: seq[kzg.KzgBlob]
+    commitments*: seq[kzg.KZGCommitment]
+    proofs*: seq[kzg.KzgProof]
+
+func getBlobList*(startId: BlobID, count: int): BlobIDs =
+  result = newSeq[BlobID](count)
+  for i in 0..<count:
+    result[i] = startId + BlobID(i)
+
+func getBlobListByIndex*(startIndex: BlobID, endIndex: BlobID): BlobIDs =
+  var count = uint64(0)
+  if endIndex > startIndex:
+    count = uint64(endIndex - startIndex + 1)
+  else:
+    count = uint64(startIndex - endIndex + 1)
+
+  result = newSeq[BlobID](count)
+  if endIndex > startIndex:
+    for i in 0..<count:
+      result[i] = startIndex + BlobID(i)
+  else:
+    for i in 0..<count:
+      result[i] = endIndex - BlobID(i)
+
+func verifyBlob*(blobId: BlobID, blob: kzg.KzgBlob): bool =
+  if blobId == 0:
+    # Blob zero is empty blob
+    var emptyFieldElem: kzg.KzgBlob
+    return emptyFieldElem == blob
+
+  # Check the blob against the deterministic data
+  let blobIdBytes = toBytesBE blobId
+
+  # First 32 bytes are the hash of the blob ID
+  var currentHashed = sha256.digest(blobIdBytes)
+
+  for chunkIdx in 0..<FIELD_ELEMENTS_PER_BLOB:
+    var expectedFieldElem = currentHashed.data
+
+    # Check that no 32 bytes chunks are greater than the BLS modulus
+    for i in 0..<32:
+      # blobByteIdx = 32 - i - 1
+      let blobByteIdx = i
+      if expectedFieldElem[blobByteIdx] < BLS_MODULUS[i]:
+        # done with this field element
+        break
+      elif expectedFieldElem[blobByteIdx] >= BLS_MODULUS[i]:
+        if BLS_MODULUS[i] > 0:
+          # This chunk is greater than the modulus, and we can reduce it in this byte position
+          expectedFieldElem[blobByteIdx] = BLS_MODULUS[i] - 1
+          # done with this field element
+          break
+        else:
+          # This chunk is greater than the modulus, but we can't reduce it in this byte position, so we will try in the next byte position
+          expectedFieldElem[blobByteIdx] = BLS_MODULUS[i]
+
+    if not equalMem(blob[chunkIdx*32].unsafeaddr, expectedFieldElem[0].addr, 32):
+      return false
+
+    # Hash the current hash
+    currentHashed = sha256.digest(currentHashed.data)
+
+  return true
+
+proc fillBlob(blobid: BlobID): KzgBlob =
+  if blobId == 0:
+    # Blob zero is empty blob, so leave as is
+    return
+
+  # Fill the blob with deterministic data
+  let blobIdBytes = toBytesBE blobId
+
+  # First 32 bytes are the hash of the blob ID
+  var currentHashed = sha256.digest(blobIdBytes)
+
+  for chunkIdx in 0..<FIELD_ELEMENTS_PER_BLOB:
+    copyMem(result[chunkIdx*32].addr, currentHashed.data[0].addr, 32)
+
+    # Check that no 32 bytes chunks are greater than the BLS modulus
+    for i in 0..<32:
+      #blobByteIdx = ((chunkIdx + 1) * 32) - i - 1
+      let blobByteIdx = (chunkIdx * 32) + i
+      if result[blobByteIdx] < BLS_MODULUS[i]:
+        # go to next chunk
+        break
+      elif result[blobByteIdx] >= BLS_MODULUS[i]:
+        if BLS_MODULUS[i] > 0:
+          # This chunk is greater than the modulus, and we can reduce it in this byte position
+          result[blobByteIdx] = BLS_MODULUS[i] - 1
+          # go to next chunk
+          break
+        else:
+          # This chunk is greater than the modulus, but we can't reduce it in this byte position, so we will try in the next byte position
+          result[blobByteIdx] = BLS_MODULUS[i]
+
+    # Hash the current hash
+    currentHashed = sha256.digest(currentHashed.data)
+
+proc generateBlob(blobid: BlobID): BlobCommitment =
+  result.blob = blobId.fillBlob()
+  let res = blobToKzgCommitment(result.blob)
+  if res.isErr:
+    doAssert(false, res.error)
+  result.commitment = res.get
+
+proc getVersionedHash*(blobid: BlobID, commitmentVersion: byte): Hash256 =
+  let res = blobId.generateBlob()
+  result = sha256.digest(res.commitment)
+  result.data[0] = commitmentVersion
+
+proc blobDataGenerator*(startBlobId: BlobID, blobCount: int): BlobTxWrapData =
+  result.blobs = newSeq[kzg.KzgBlob](blobCount)
+  result.commitments = newSeq[kzg.KZGCommitment](blobCount)
+  result.hashes = newSeq[Hash256](blobCount)
+  result.proofs = newSeq[kzg.KzgProof](blobCount)
+
+  for i in 0..<blobCount:
+    let res = generateBlob(startBlobId + BlobID(i))
+    result.blobs[i] = res.blob
+    result.commitments[i] = res.commitment
+    result.hashes[i] = kzgToVersionedHash(result.commitments[i])
+    let z = computeBlobKzgProof(result.blobs[i], result.commitments[i])
+    if z.isErr:
+      doAssert(false, z.error)
+    result.proofs[i] = z.get()
diff --git a/hive_integration/nodocker/engine/cancun/customizer.nim b/hive_integration/nodocker/engine/cancun/customizer.nim
new file mode 100644
index 000000000..b16b4002b
--- /dev/null
+++ b/hive_integration/nodocker/engine/cancun/customizer.nim
@@ -0,0 +1,683 @@
+import
+  std/[options, strutils, typetraits, random],
+  nimcrypto/sysrand,
+  stew/byteutils,
+  ./blobs,
+  ../tx_sender,
+  ../../../../nimbus/constants,
+  ../../../../nimbus/utils/utils,
+  ../../../../nimbus/common as nimbus_common,
+  ../../../../nimbus/beacon/web3_eth_conv,
+  ../../../../nimbus/beacon/payload_conv,
+  ../../../../nimbus/beacon/execution_types
+
+type
+  EngineAPIVersionResolver* = ref object of RootRef
+    com: CommonRef
+
+method setEngineAPIVersionResolver*(cust: EngineAPIVersionResolver, v: CommonRef) {.base.} =
+  cust.com = v
+
+method forkchoiceUpdatedVersion*(cust: EngineAPIVersionResolver,
+  headTimestamp: uint64, payloadAttributesTimestamp: Option[uint64]): Version {.base.} =
+  let ts = if payloadAttributesTimestamp.isNone: headTimestamp.EthTime
+           else: payloadAttributesTimestamp.get().EthTime
+  if cust.com.isCancunOrLater(ts):
+    Version.V3
+  elif cust.com.isShanghaiOrLater(ts):
+    Version.V2
+  else:
+    Version.V1
+
+method newPayloadVersion*(cust: EngineAPIVersionResolver, timestamp: uint64): Version {.base.} =
+  let ts = timestamp.EthTime
+  if cust.com.isCancunOrLater(ts):
+    Version.V3
+  elif cust.com.isShanghaiOrLater(ts):
+    Version.V2
+  else:
+    Version.V1
+
+method getPayloadVersion*(cust: EngineAPIVersionResolver, timestamp: uint64): Version {.base.} =
+  let ts = timestamp.EthTime
+  if cust.com.isCancunOrLater(ts):
+    Version.V3
+  elif cust.com.isShanghaiOrLater(ts):
+    Version.V2
+  else:
+    Version.V1
+
+type
+  GetPayloadCustomizer* = ref object of EngineAPIVersionResolver
+
+method getPayloadID*(cust: GetPayloadCustomizer,
+         basePayloadID: PayloadID): PayloadID {.base.} =
+  doAssert(false, "getPayloadID unimplemented")
+
+method getExpectedError*(cust: GetPayloadCustomizer): int {.base.} =
+  doAssert(false, "getExpectedError unimplemented")
+
+type
+  BaseGetPayloadCustomizer* = ref object of GetPayloadCustomizer
+    customPayloadID: Option[PayloadID]
+    expectedError  : int
+
+method getPayloadID(cust: BaseGetPayloadCustomizer,
+         basePayloadID: PayloadID): PayloadID =
+  if cust.customPayloadID.isSome:
+    return cust.customPayloadID.get
+  return basePayloadID
+
+method getExpectedError(cust: BaseGetPayloadCustomizer): int =
+  cust.expectedError
+
+type
+  UpgradegetPayloadVersion* = ref object of GetPayloadCustomizer
+
+method getPayloadVersion(cust: UpgradegetPayloadVersion, timestamp: uint64): Version =
+  let version = procCall getPayloadVersion(cust.GetPayloadCustomizer, timestamp)
+  doAssert(version != Version.high, "cannot upgrade version " & $Version.high)
+  version.succ
+
+type
+  DowngradegetPayloadVersion* = ref object of GetPayloadCustomizer
+
+method getPayloadVersion(cust: DowngradegetPayloadVersion, timestamp: uint64): Version =
+  let version = procCall getPayloadVersion(cust.GetPayloadCustomizer, timestamp)
+  doAssert(version != Version.V1, "cannot downgrade version 1")
+  version.pred
+
+type
+  PayloadAttributesCustomizer* = ref object of GetPayloadCustomizer
+
+method getPayloadAttributes*(cust: PayloadAttributesCustomizer, basePayloadAttributes: PayloadAttributes): PayloadAttributes {.base.} =
+  doAssert(false, "getPayloadAttributes unimplemented")
+
+type
+  BasePayloadAttributesCustomizer* = ref object of PayloadAttributesCustomizer
+    timestamp             : Option[uint64]
+    prevRandao            : Option[common.Hash256]
+    suggestedFeeRecipient : Option[common.EthAddress]
+    withdrawals           : Option[seq[Withdrawal]]
+    removeWithdrawals     : bool
+    beaconRoot            : Option[common.Hash256]
+    removeBeaconRoot      : bool
+
+method getPayloadAttributes(cust: BasePayloadAttributesCustomizer, basePayloadAttributes: PayloadAttributes): PayloadAttributes =
+  var customPayloadAttributes = PayloadAttributes(
+    timestamp:             basePayloadAttributes.timestamp,
+    prevRandao:            basePayloadAttributes.prevRandao,
+    suggestedFeeRecipient: basePayloadAttributes.suggestedFeeRecipient,
+    withdrawals:           basePayloadAttributes.withdrawals,
+    parentBeaconBlockRoot: basePayloadAttributes.parentBeaconBlockRoot,
+  )
+
+  if cust.timestamp.isSome:
+    customPayloadAttributes.timestamp = w3Qty cust.timestamp.get
+
+  if cust.prevRandao.isSome:
+    customPayloadAttributes.prevRandao = w3Hash cust.prevRandao.get
+
+  if cust.suggestedFeeRecipient.isSome:
+    customPayloadAttributes.suggestedFeeRecipient = w3Addr cust.suggestedFeeRecipient.get
+
+  if cust.removeWithdrawals:
+    customPayloadAttributes.withdrawals = none(seq[WithdrawalV1])
+  elif cust.withdrawals.isSome:
+    customPayloadAttributes.withdrawals = w3Withdrawals cust.withdrawals
+
+  if cust.removeBeaconRoot:
+    customPayloadAttributes.parentBeaconBlockRoot = none(Web3Hash)
+  elif cust.beaconRoot.isSome:
+    customPayloadAttributes.parentBeaconBlockRoot = w3Hash cust.beaconRoot
+
+  return customPayloadAttributes
+
+type
+  TimestampDeltaPayloadAttributesCustomizer* = ref object of BasePayloadAttributesCustomizer
+    timestampDelta: uint64
+
+method getPayloadAttributes(cust: TimestampDeltaPayloadAttributesCustomizer, basePayloadAttributes: PayloadAttributes): PayloadAttributes =
+  var customPayloadAttributes = procCall getPayloadAttributes(cust.BasePayloadAttributesCustomizer, basePayloadAttributes)
+  customPayloadAttributes.timestamp = w3Qty(customPayloadAttributes.timestamp, cust.timestampDelta)
+  return customPayloadAttributes
+
+type
+  ForkchoiceUpdatedCustomizer* = ref object of BasePayloadAttributesCustomizer
+
+method getForkchoiceState*(cust: ForkchoiceUpdatedCustomizer,
+  baseForkchoiceUpdate: ForkchoiceStateV1): ForkchoiceStateV1 {.base.} =
+  doAssert(false, "getForkchoiceState unimplemented")
+
+method getExpectInvalidStatus*(cust: ForkchoiceUpdatedCustomizer): bool {.base.} =
+  doAssert(false, "getExpectInvalidStatus unimplemented")
+
+# Customizer that makes no modifications to the forkchoice directive call.
+# Used as base to other customizers.
+type
+  BaseForkchoiceUpdatedCustomizer* = ref object of ForkchoiceUpdatedCustomizer
+    expectedError      : int
+    expectInvalidStatus: bool
+
+method getPayloadAttributes(cust: BaseForkchoiceUpdatedCustomizer, basePayloadAttributes: PayloadAttributes): PayloadAttributes =
+  var customPayloadAttributes = procCall getPayloadAttributes(cust.BasePayloadAttributesCustomizer, basePayloadAttributes)
+  return customPayloadAttributes
+
+method getForkchoiceState(cust: BaseForkchoiceUpdatedCustomizer, baseForkchoiceUpdate: ForkchoiceStateV1): ForkchoiceStateV1 =
+  return baseForkchoiceUpdate
+
+method getExpectedError(cust: BaseForkchoiceUpdatedCustomizer): int =
+  return cust.expectedError
+
+method getExpectInvalidStatus(cust: BaseForkchoiceUpdatedCustomizer): bool =
+  return cust.expectInvalidStatus
+
+# Customizer that upgrades the version of the forkchoice directive call to the next version.
+type
+  UpgradeforkchoiceUpdatedVersion* = ref object of BaseForkchoiceUpdatedCustomizer
+
+method forkchoiceUpdatedVersion(cust: UpgradeforkchoiceUpdatedVersion, headTimestamp: uint64, payloadAttributesTimestamp: Option[uint64]): Version =
+  let version = procCall forkchoiceUpdatedVersion(EngineAPIVersionResolver(cust), headTimestamp, payloadAttributesTimestamp)
+  doAssert(version != Version.high, "cannot upgrade version " & $Version.high)
+  version.succ
+
+# Customizer that downgrades the version of the forkchoice directive call to the previous version.
+type
+  DowngradeforkchoiceUpdatedVersion* = ref object of BaseForkchoiceUpdatedCustomizer
+
+method forkchoiceUpdatedVersion(cust: DowngradeforkchoiceUpdatedVersion, headTimestamp: uint64, payloadAttributesTimestamp: Option[uint64]): Version =
+  let version = procCall forkchoiceUpdatedVersion(EngineAPIVersionResolver(cust), headTimestamp, payloadAttributesTimestamp)
+  doAssert(version != Version.V1, "cannot downgrade version 1")
+  version.pred
+
+type
+  VersionedHashRef* = ref object of RootRef
+    blobs*: seq[BlobID]
+    hashVersions*: seq[byte]
+
+proc getVersionedHashes*(v: VersionedHashRef): seq[common.Hash256] =
+  if v.blobs.len == 0:
+    return @[]
+
+  result = newSeq[common.Hash256](v.blobs.len)
+
+  var version: byte
+  for i, blobID in v.blobs:
+    if v.hashVersions.len > i:
+      version = v.hashVersions[i]
+    result[i] = blobID.getVersionedHash(version)
+
+proc description*(v: VersionedHashRef): string =
+  result = "VersionedHashes: "
+  for x in v.blobs:
+    result.add x.toHex
+
+  if v.hashVersions.len > 0:
+    result.add " with versions "
+    result.add v.hashVersions.toHex
+
+type
+  VersionedHashesCustomizer* = ref object of RootRef
+  IncreaseVersionVersionedHashes* = ref object of VersionedHashesCustomizer
+
+method getVersionedHashes*(cust: VersionedHashesCustomizer, baseVersionedHashes: openArray[common.Hash256]): seq[common.Hash256] {.base.} =
+  doAssert(false, "getVersionedHashes unimplemented")
+
+method getVersionedHashes(cust: IncreaseVersionVersionedHashes, baseVersionedHashes: openArray[common.Hash256]): seq[common.Hash256] =
+  doAssert(baseVersionedHashes.len > 0, "no versioned hashes available for modification")
+
+  result = newSeq[common.Hash256](baseVersionedHashes.len)
+  for i, h in baseVersionedHashes:
+    result[i] = h
+    result[i].data[0] = result[i].data[0] + 1
+
+type
+  CorruptVersionedHashes* = ref object of VersionedHashesCustomizer
+
+method getVersionedHashes(cust: CorruptVersionedHashes, baseVersionedHashes: openArray[common.Hash256]): seq[common.Hash256] =
+  doAssert(baseVersionedHashes.len > 0, "no versioned hashes available for modification")
+
+  result = newSeq[common.Hash256](baseVersionedHashes.len)
+  for i, h in baseVersionedHashes:
+    result[i] = h
+    result[i].data[h.data.len-1] = result[i].data[h.data.len-1] + 1
+
+type
+  RemoveVersionedHash* = ref object of VersionedHashesCustomizer
+
+method getVersionedHashes(cust: RemoveVersionedHash, baseVersionedHashes: openArray[common.Hash256]): seq[common.Hash256] =
+  doAssert(baseVersionedHashes.len > 0, "no versioned hashes available for modification")
+
+  result = newSeq[common.Hash256](baseVersionedHashes.len - 1)
+  for i, h in baseVersionedHashes:
+    if i < baseVersionedHashes.len-1:
+      result[i] = h
+      result[i].data[h.data.len-1] = result[i].data[h.data.len-1] + 1
+
+type
+  ExtraVersionedHash* = ref object of VersionedHashesCustomizer
+
+method getVersionedHashes(cust: ExtraVersionedHash, baseVersionedHashes: openArray[common.Hash256]): seq[common.Hash256] =
+  result = newSeq[common.Hash256](baseVersionedHashes.len + 1)
+  for i, h in baseVersionedHashes:
+    result[i] = h
+
+  var extraHash: common.Hash256
+  doAssert randomBytes(extraHash.data) == 32
+  extraHash.data[0] = VERSIONED_HASH_VERSION_KZG
+  result[^1] = extraHash
+
+
+type
+  PayloadCustomizer* = ref object of EngineAPIVersionResolver
+
+  ExecutableData* = object
+    basePayload*: ExecutionPayload
+    beaconRoot* : Option[common.Hash256]
+    attr*       : PayloadAttributes
+    versionedHashes*: seq[common.Hash256]
+
+method customizePayload(cust: PayloadCustomizer, data: ExecutableData): ExecutableData {.base.} =
+  doAssert(false, "customizePayload unimplemented")
+
+method getTimestamp(cust: PayloadCustomizer, basePayload: ExecutionPayload): uint64 {.base.} =
+  doAssert(false, "getTimestamp unimplemented")
+
+type
+  NewPayloadCustomizer* = ref object of PayloadCustomizer
+
+method getExpectedError(cust: NewPayloadCustomizer): int {.base.} =
+  doAssert(false, "getExpectedError unimplemented")
+
+method getExpectInvalidStatus(cust: NewPayloadCustomizer): bool {.base.} =
+  doAssert(false, "getExpectInvalidStatus unimplemented")
+
+type
+  CustomPayloadData = object
+    parentHash*               : Option[common.Hash256]
+    feeRecipient*             : Option[common.EthAddress]
+    stateRoot*                : Option[common.Hash256]
+    receiptsRoot*             : Option[common.Hash256]
+    logsBloom*                : Option[BloomFilter]
+    prevRandao*               : Option[common.Hash256]
+    number*                   : Option[uint64]
+    gasLimit*                 : Option[GasInt]
+    gasUsed*                  : Option[GasInt]
+    timestamp*                : Option[uint64]
+    extraData*                : Option[common.Blob]
+    baseFeePerGas*            : Option[UInt256]
+    blockHash*                : Option[common.Hash256]
+    transactions*             : Option[seq[Transaction]]
+    withdrawals*              : Option[seq[Withdrawal]]
+    removeWithdrawals*        : bool
+    blobGasUsed*              : Option[uint64]
+    removeBlobGasUsed*        : bool
+    excessBlobGas*            : Option[uint64]
+    removeExcessBlobGas*      : bool
+    parentBeaconRoot*         : Option[common.Hash256]
+    removeParentBeaconRoot*   : bool
+    versionedHashesCustomizer*: VersionedHashesCustomizer
+
+func getTimestamp*(cust: CustomPayloadData, basePayload: ExecutionPayload): uint64 =
+  if cust.timestamp.isSome:
+    return cust.timestamp.get
+  return basePayload.timestamp.uint64
+
+# Construct a customized payload by taking an existing payload as base and mixing it CustomPayloadData
+# blockHash is calculated automatically.
+proc customizePayload*(cust: CustomPayloadData, data: ExecutableData): ExecutableData =
+  var customHeader = blockHeader(data.basePayload, data.beaconRoot)
+
+  if cust.transactions.isSome:
+    customHeader.txRoot = calcTxRoot(cust.transactions.get)
+
+  # Overwrite custom information
+  if cust.parentHash.isSome:
+    customHeader.parentHash = cust.parentHash.get
+
+  if cust.feeRecipient.isSome:
+    customHeader.coinbase = cust.feeRecipient.get
+
+  if cust.stateRoot.isSome:
+    customHeader.stateRoot = cust.stateRoot.get
+
+  if cust.receiptsRoot.isSome:
+    customHeader.receiptRoot = cust.receiptsRoot.get
+
+  if cust.logsBloom.isSome:
+    customHeader.bloom = cust.logsBloom.get
+
+  if cust.prevRandao.isSome:
+    customHeader.mixDigest = cust.prevRandao.get
+
+  if cust.number.isSome:
+    customHeader.blockNumber = cust.number.get.u256
+
+  if cust.gasLimit.isSome:
+    customHeader.gasLimit = cust.gasLimit.get
+
+  if cust.gasUsed.isSome:
+    customHeader.gasUsed = cust.gasUsed.get
+
+  if cust.timestamp.isSome:
+    customHeader.timestamp = cust.timestamp.get.EthTime
+
+  if cust.extraData.isSome:
+    customHeader.extraData = cust.extraData.get
+
+  if cust.baseFeePerGas.isSome:
+    customHeader.fee = cust.baseFeePerGas
+
+  if cust.removeWithdrawals:
+    customHeader.withdrawalsRoot = none(common.Hash256)
+  elif cust.withdrawals.isSome:
+    let h = calcWithdrawalsRoot(cust.withdrawals.get)
+    customHeader.withdrawalsRoot = some(h)
+
+  if cust.removeBlobGasUsed:
+    customHeader.blobGasUsed = none(uint64)
+  elif cust.blobGasUsed.isSome:
+    customHeader.blobGasUsed = cust.blobGasUsed
+
+  if cust.removeExcessBlobGas:
+    customHeader.excessBlobGas = none(uint64)
+  elif cust.excessBlobGas.isSome:
+    customHeader.excessBlobGas = cust.excessBlobGas
+
+  if cust.removeParentBeaconRoot:
+    customHeader.parentBeaconBlockRoot = none(common.Hash256)
+  elif cust.parentBeaconRoot.isSome:
+    customHeader.parentBeaconBlockRoot = cust.parentBeaconRoot
+
+  var blk = EthBlock(
+    header: customHeader,
+  )
+
+  if cust.removeWithdrawals:
+    blk.withdrawals = none(seq[Withdrawal])
+  elif cust.withdrawals.isSome:
+    blk.withdrawals = cust.withdrawals
+  elif data.basePayload.withdrawals.isSome:
+    blk.withdrawals = ethWithdrawals data.basePayload.withdrawals
+
+  result = ExecutableData(
+    basePayload    : executionPayload(blk),
+    beaconRoot     : blk.header.parentBeaconBlockRoot,
+    attr           : data.attr,
+    versionedHashes: data.versionedHashes,
+  )
+
+  if cust.versionedHashesCustomizer.isNil.not:
+    result.versionedHashes = cust.versionedHashesCustomizer.getVersionedHashes(data.versionedHashes)
+
+
+# Base new payload directive call cust.
+# Used as base to other customizers.
+type
+  BaseNewPayloadVersionCustomizer* = ref object of NewPayloadCustomizer
+    payloadCustomizer*  : CustomPayloadData
+    expectedError*      : int
+    expectInvalidStatus*: bool
+
+method customizePayload(cust: BaseNewPayloadVersionCustomizer, data: ExecutableData): ExecutableData =
+  cust.payloadCustomizer.customizePayload(data)
+
+method getExpectedError(cust: BaseNewPayloadVersionCustomizer): int =
+  cust.expectedError
+
+method getExpectInvalidStatus(cust: BaseNewPayloadVersionCustomizer): bool =
+  cust.expectInvalidStatus
+
+# Customizer that upgrades the version of the payload to the next version.
+type
+  UpgradeNewPayloadVersion* = ref object of NewPayloadCustomizer
+
+method newPayloadVersion(cust: UpgradeNewPayloadVersion, timestamp: uint64): Version =
+  let version = procCall newPayloadVersion(EngineAPIVersionResolver(cust), timestamp)
+  doAssert(version != Version.high, "cannot upgrade version " & $Version.high)
+  version.succ
+
+# Customizer that downgrades the version of the payload to the previous version.
+type
+  DowngradeNewPayloadVersion* = ref object of NewPayloadCustomizer
+
+method newPayloadVersion(cust: DowngradeNewPayloadVersion, timestamp: uint64): Version =
+  let version = procCall newPayloadVersion(EngineAPIVersionResolver(cust), timestamp)
+  doAssert(version != Version.V1, "cannot downgrade version 1")
+  version.pred
+
+proc customizePayloadTransactions*(data: ExecutableData, customTransactions: openArray[Transaction]): ExecutableData =
+  let cpd = CustomPayloadData(
+    transactions: some(@customTransactions),
+  )
+  customizePayload(cpd, data)
+
+proc `$`*(cust: CustomPayloadData): string =
+  var fieldList = newSeq[string]()
+
+  if cust.parentHash.isSome:
+    fieldList.add "parentHash=" & cust.parentHash.get.short
+
+  if cust.feeRecipient.isSome:
+    fieldList.add "Coinbase=" & $cust.feeRecipient.get
+
+  if cust.stateRoot.isSome:
+    fieldList.add "stateRoot=" & cust.stateRoot.get.short
+
+  if cust.receiptsRoot.isSome:
+    fieldList.add "receiptsRoot=" & cust.receiptsRoot.get.short
+
+  if cust.logsBloom.isSome:
+    fieldList.add "logsBloom=" & cust.logsBloom.get.toHex
+
+  if cust.prevRandao.isSome:
+    fieldList.add "prevRandao=" & cust.prevRandao.get.short
+
+  if cust.number.isSome:
+    fieldList.add "Number=" & $cust.number.get
+
+  if cust.gasLimit.isSome:
+    fieldList.add "gasLimit=" & $cust.gasLimit.get
+
+  if cust.gasUsed.isSome:
+    fieldList.add "gasUsed=" & $cust.gasUsed.get
+
+  if cust.timestamp.isSome:
+    fieldList.add "timestamp=" & $cust.timestamp.get
+
+  if cust.extraData.isSome:
+    fieldList.add "extraData=" & cust.extraData.get.toHex
+
+  if cust.baseFeePerGas.isSome:
+    fieldList.add "baseFeePerGas=" & $cust.baseFeePerGas.get
+
+  if cust.transactions.isSome:
+    fieldList.add "transactions=" & $cust.transactions.get.len
+
+  if cust.withdrawals.isSome:
+    fieldList.add "withdrawals=" & $cust.withdrawals.get.len
+
+  fieldList.join(", ")
+
+type
+  InvalidPayloadBlockField* = enum
+    InvalidParentHash
+    InvalidStateRoot
+    InvalidReceiptsRoot
+    InvalidNumber
+    InvalidGasLimit
+    InvalidGasUsed
+    InvalidTimestamp
+    InvalidPrevRandao
+    RemoveTransaction
+    InvalidTransactionSignature
+    InvalidTransactionNonce
+    InvalidTransactionGas
+    InvalidTransactionGasPrice
+    InvalidTransactionValue
+    InvalidTransactionGasTipPrice
+    InvalidTransactionChainID
+    InvalidParentBeaconBlockRoot
+    InvalidExcessBlobGas
+    InvalidBlobGasUsed
+    InvalidBlobCountGasUsed
+    InvalidVersionedHashesVersion
+    InvalidVersionedHashes
+    IncompleteVersionedHashes
+    ExtraVersionedHashes
+    InvalidWithdrawals
+
+func scramble(data: Web3Hash): Option[common.Hash256] =
+  var h = ethHash data
+  h.data[^1] = byte(255 - h.data[^1])
+  some(h)
+
+func scramble(data: common.Hash256): Option[common.Hash256] =
+  var h = data
+  h.data[^1] = byte(255 - h.data[^1])
+  some(h)
+
+# This function generates an invalid payload by taking a base payload and modifying the specified field such that it ends up being invalid.
+# One small consideration is that the payload needs to contain transactions and specially transactions using the PREVRANDAO opcode for all the fields to be compatible with this function.
+proc generateInvalidPayload*(sender: TxSender, data: ExecutableData, payloadField: InvalidPayloadBlockField): ExecutableData =
+  var customPayloadMod: CustomPayloadData
+  let basePayload = data.basePayload
+
+  case payloadField
+  of InvalidParentHash:
+    customPayloadMod = CustomPayloadData(
+      parentHash: scramble(basePayload.parentHash),
+    )
+  of InvalidStateRoot:
+    customPayloadMod = CustomPayloadData(
+      stateRoot: scramble(basePayload.stateRoot),
+    )
+  of InvalidReceiptsRoot:
+    customPayloadMod = CustomPayloadData(
+      receiptsRoot: scramble(basePayload.receiptsRoot),
+    )
+  of InvalidNumber:
+    let modNumber = basePayload.blockNumber.uint64 - 1
+    customPayloadMod = CustomPayloadData(
+      number: some(modNumber),
+    )
+  of InvalidGasLimit:
+    let modGasLimit = basePayload.gasLimit.GasInt * 2
+    customPayloadMod = CustomPayloadData(
+      gasLimit: some(modGasLimit),
+    )
+  of InvalidGasUsed:
+    let modGasUsed = basePayload.gasUsed.GasInt - 1
+    customPayloadMod = CustomPayloadData(
+      gasUsed: some(modGasUsed),
+    )
+  of InvalidTimestamp:
+    let modTimestamp = basePayload.timestamp.uint64 - 1
+    customPayloadMod = CustomPayloadData(
+      timestamp: some(modTimestamp),
+    )
+  of InvalidPrevRandao:
+    # This option potentially requires a transaction that uses the PREVRANDAO opcode.
+    # Otherwise the payload will still be valid.
+    var randomHash: common.Hash256
+    doAssert randomBytes(randomHash.data) == 32
+    customPayloadMod = CustomPayloadData(
+      prevRandao: some(randomHash),
+    )
+  of InvalidParentBeaconBlockRoot:
+    doAssert(data.beaconRoot.isSome,
+      "no parent beacon block root available for modification")
+    customPayloadMod = CustomPayloadData(
+      parentBeaconRoot: scramble(data.beaconRoot.get),
+    )
+  of InvalidBlobGasUsed:
+    doAssert(basePayload.blobGasUsed.isSome, "no blob gas used available for modification")
+    let modBlobGasUsed = basePayload.blobGasUsed.get.uint64 + 1
+    customPayloadMod = CustomPayloadData(
+      blobGasUsed: some(modBlobGasUsed),
+    )
+  of InvalidBlobCountGasUsed:
+    doAssert(basePayload.blobGasUsed.isSome, "no blob gas used available for modification")
+    let modBlobGasUsed = basePayload.blobGasUsed.get.uint64 + GAS_PER_BLOB
+    customPayloadMod = CustomPayloadData(
+      blobGasUsed: some(modBlobGasUsed),
+    )
+  of InvalidExcessBlobGas:
+    doAssert(basePayload.excessBlobGas.isSome, "no excess blob gas available for modification")
+    let modExcessBlobGas = basePayload.excessBlobGas.get.uint64 + 1
+    customPayloadMod = CustomPayloadData(
+      excessBlobGas: some(modExcessBlobGas),
+    )
+  of InvalidVersionedHashesVersion:
+    doAssert(data.versionedHashes.len > 0, "no versioned hashes available for modification")
+    customPayloadMod = CustomPayloadData(
+      versionedHashesCustomizer: IncreaseVersionVersionedHashes(),
+    )
+  of InvalidVersionedHashes:
+    doAssert(data.versionedHashes.len > 0, "no versioned hashes available for modification")
+    customPayloadMod = CustomPayloadData(
+      versionedHashesCustomizer: CorruptVersionedHashes(),
+    )
+  of IncompleteVersionedHashes:
+    doAssert(data.versionedHashes.len > 0, "no versioned hashes available for modification")
+    customPayloadMod = CustomPayloadData(
+      versionedHashesCustomizer: RemoveVersionedHash(),
+    )
+  of ExtraVersionedHashes:
+    doAssert(data.versionedHashes.len > 0, "no versioned hashes available for modification")
+    customPayloadMod = CustomPayloadData(
+      versionedHashesCustomizer: ExtraVersionedHash(),
+    )
+  of InvalidWithdrawals:
+    # These options are not supported yet.
+    # TODO: Implement
+    doAssert(false, "invalid payload field not supported yet: " & $payloadField)
+  of RemoveTransaction:
+    let emptyTxs = newSeq[Transaction]()
+    customPayloadMod = CustomPayloadData(
+      transactions: some(emptyTxs),
+    )
+  of InvalidTransactionSignature,
+    InvalidTransactionNonce,
+    InvalidTransactionGas,
+    InvalidTransactionGasPrice,
+    InvalidTransactionGasTipPrice,
+    InvalidTransactionValue,
+    InvalidTransactionChainID:
+
+    doAssert(basePayload.transactions.len > 0, "no transactions available for modification")
+    let baseTx = rlp.decode(distinctBase basePayload.transactions[0], Transaction)
+    var custTx: CustomTransactionData
+
+    case payloadField
+    of InvalidTransactionSignature:
+      custTx.signature = some(baseTx.R - 1.u256)
+    of InvalidTransactionNonce:
+      custTx.nonce = some(baseTx.nonce - 1)
+    of InvalidTransactionGas:
+      custTx.gas = some(0.GasInt)
+    of InvalidTransactionGasPrice:
+      custTx.gasPriceOrGasFeeCap = some(0.GasInt)
+    of InvalidTransactionGasTipPrice:
+      custTx.gasTipCap = some(gasTipPrice.GasInt * 2.GasInt)
+    of InvalidTransactionValue:
+      # Vault account initially has 0x123450000000000000000, so this value should overflow
+      custTx.value = some(UInt256.fromHex("0x123450000000000000001"))
+    of InvalidTransactionChainID:
+      custTx.chainId = some(ChainId(baseTx.chainId.uint64 + 1))
+    else: discard
+
+    let modifiedTx = sender.customizeTransaction(baseTx, custTx)
+    customPayloadMod = CustomPayloadData(
+      transactions: some(@[modifiedTx]),
+    )
+
+  customPayloadMod.customizePayload(data)
+
+# Generates an alternative withdrawals list that contains the same
+# amounts and accounts, but the order in the list is different, so
+# stateRoot of the resulting payload should be the same.
+
+proc randomizeWithdrawalsOrder(src: openArray[Withdrawal]): seq[Withdrawal] =
+  result = @src
+  result.shuffle
diff --git a/hive_integration/nodocker/engine/cancun/helpers.nim b/hive_integration/nodocker/engine/cancun/helpers.nim
new file mode 100644
index 000000000..1105aa731
--- /dev/null
+++ b/hive_integration/nodocker/engine/cancun/helpers.nim
@@ -0,0 +1,216 @@
+import
+  std/[tables, strutils, typetraits],
+  stint,
+  eth/[common, rlp],
+  eth/common/eth_types_rlp,
+  chronicles,
+  stew/[results, byteutils],
+  kzg4844/kzg_ex as kzg,
+  ../types,
+  ../engine_client,
+  ../../../../nimbus/constants,
+  ../../../../nimbus/core/eip4844,
+  ../../../../nimbus/rpc/rpc_types,
+  ../../../../nimbus/beacon/execution_types,
+  ../../../../nimbus/beacon/web3_eth_conv,
+  ./blobs
+
+type
+  TestBlobTxPool* = ref object
+    currentBlobID* : BlobID
+    currentTxIndex*: int
+    transactions*  : Table[common.Hash256, Transaction]
+    hashesByIndex* : Table[int, common.Hash256]
+
+const
+  HISTORY_BUFFER_LENGTH* = 8191
+
+  # Test constants
+  DATAHASH_START_ADDRESS* = toAddress(0x20000.u256)
+  DATAHASH_ADDRESS_COUNT* = 1000
+
+func getMinExcessBlobGasForBlobGasPrice(data_gas_price: uint64): uint64 =
+  var
+    current_excess_data_gas = 0'u64
+    current_data_gas_price  = 1'u64
+
+  while current_data_gas_price < data_gas_price:
+    current_excess_data_gas += GAS_PER_BLOB.uint64
+    current_data_gas_price = getBlobGasPrice(current_excess_data_gas).truncate(uint64)
+
+  return current_excess_data_gas
+
+func getMinExcessBlobsForBlobGasPrice*(data_gas_price: uint64): uint64 =
+  return getMinExcessBlobGasForBlobGasPrice(data_gas_price) div GAS_PER_BLOB.uint64
+
+proc addBlobTransaction*(pool: TestBlobTxPool, tx: Transaction) =
+  let txHash = rlpHash(tx)
+  pool.transactions[txHash] = tx
+
+proc `==`(a: openArray[rpc_types.AccessTuple], b: openArray[AccessPair]): bool =
+  if a.len != b.len:
+    return false
+
+  for i in 0..<a.len:
+    if a[i].address != b[i].address:
+      return false
+    if a[i].storageKeys.len != b[i].storageKeys.len:
+      return false
+    for j in 0..<a[i].storageKeys.len:
+      if a[i].storageKeys[j].data != b[i].storageKeys[j]:
+        return false
+
+  return true
+
+# Test two different transactions with the same blob, and check the blob bundle.
+proc verifyTransactionFromNode*(client: RpcClient, tx: Transaction): Result[void, string] =
+  let txHash = tx.rlpHash
+  let res = client.txByHash(txHash)
+  if res.isErr:
+    return err(res.error)
+  let returnedTx = res.get()
+
+  # Verify that the tx fields are all the same
+  if returnedTx.nonce != tx.nonce:
+    return err("nonce mismatch: $1 != $2" % [$returnedTx.nonce, $tx.nonce])
+
+  if returnedTx.gasLimit != tx.gasLimit:
+    return err("gas mismatch: $1 != $2" % [$returnedTx.gasLimit, $tx.gasLimit])
+
+  if returnedTx.gasPrice != tx.gasPrice:
+    return err("gas price mismatch: $1 != $2" % [$returnedTx.gasPrice, $tx.gasPrice])
+
+  if returnedTx.value != tx.value:
+    return err("value mismatch: $1 != $2" % [$returnedTx.value, $tx.value])
+
+  if returnedTx.to != tx.to:
+    return err("to mismatch: $1 != $2" % [$returnedTx.to, $tx.to])
+
+  if returnedTx.payload != tx.payload:
+    return err("data mismatch: $1 != $2" % [returnedTx.payload.toHex, tx.payload.toHex])
+
+  if returnedTx.accessList.isNone:
+    return err("expect accessList is some")
+
+  let ac = returnedTx.accessList.get
+  if ac != tx.accessList:
+    return err("access list mismatch")
+
+  if returnedTx.chainId.isNone:
+    return err("chain id is none, expect is some")
+
+  if returnedTx.chainId.get.uint64 != tx.chainId.uint64:
+    return err("chain id mismatch: $1 != $2" % [$returnedTx.chainId.get.uint64, $tx.chainId.uint64])
+
+  if returnedTx.maxFeePerGas != tx.maxFee:
+    return err("max fee per gas mismatch: $1 != $2" % [$returnedTx.maxFeePerGas, $tx.maxFee])
+
+  if returnedTx.maxPriorityFeePerGas != tx.maxPriorityFee:
+    return err("max priority fee per gas mismatch: $1 != $2" % [$returnedTx.maxPriorityFeePerGas, $tx.maxPriorityFee])
+
+  if returnedTx.maxFeePerBlobGas.isNone:
+    return err("expect maxFeePerBlobGas is some")
+
+  if returnedTx.maxFeePerBlobGas.get != tx.maxFeePerBlobGas:
+    return err("max fee per data gas mismatch: $1 != $2" % [$returnedTx.maxFeePerBlobGas.get, $tx.maxFeePerBlobGas])
+
+  if returnedTx.versionedHashes.isNone:
+    return err("expect versioned hashes is some")
+
+  let vs = returnedTx.versionedHashes.get
+  if vs != tx.versionedHashes:
+    return err("blob versioned hashes mismatch")
+
+  if returnedTx.txType != tx.txType:
+    return err("type mismatch: $1 != $2" % [$returnedTx.txType, $tx.txType])
+
+  ok()
+
+proc beaconRootStorageIndexes*(timestamp: uint64): (UInt256, UInt256) =
+  # Calculate keys
+  let
+    timestampReduced = timestamp mod HISTORY_BUFFER_LENGTH
+    timestampExtended = timestampReduced + HISTORY_BUFFER_LENGTH
+
+  (timestampReduced.u256, timestampExtended.u256)
+
+
+type
+  BlobWrapData* = object
+    versionedHash*: common.Hash256
+    blob*         : kzg.KzgBlob
+    commitment*   : kzg.KZGCommitment
+    proof*        : kzg.KzgProof
+
+  BlobData* = ref object
+    txs*  : seq[Transaction]
+    data*: seq[BlobWrapData]
+
+proc getBlobDataInPayload*(pool: TestBlobTxPool, payload: ExecutionPayload): Result[BlobData, string] =
+  var blobData = BlobData()
+
+  # Find all blob transactions included in the payload
+  for binaryTx in payload.transactions:
+    # Unmarshal the tx from the payload, which should be the minimal version
+    # of the blob transaction
+    let txData = rlp.decode(distinctBase binaryTx, Transaction)
+    if txData.txType != TxEIP4844:
+      continue
+
+    let txHash = rlpHash(txData)
+
+    # Find the transaction in the current pool of known transactions
+    if not pool.transactions.hasKey(txHash):
+      return err("could not find transaction in the pool")
+
+    let blobTx = pool.transactions[txHash]
+    if blobTx.networkPayload.isNil:
+      return err("blob data is nil")
+
+    let np = blobTx.networkPayload
+    if blobTx.versionedHashes.len != np.commitments.len or
+       np.commitments.len != np.blobs.len or
+       np.blobs.len != np.proofs.len:
+      return err("invalid blob wrap data")
+
+    for i in 0..<blobTx.versionedHashes.len:
+      blobData.data.add BlobWrapData(
+        versionedHash: blobTx.versionedHashes[i],
+        commitment   : np.commitments[i],
+        blob         : np.blobs[i],
+        proof        : np.proofs[i],
+      )
+    blobData.txs.add blobTx
+
+  return ok(blobData)
+
+proc verifyBeaconRootStorage*(client: RpcClient, payload: ExecutionPayload): bool =
+  # Read the storage keys from the stateful precompile that stores the beacon roots and verify
+  # that the beacon root is the same as the one in the payload
+  let
+    blockNumber = u256 payload.blockNumber
+    precompileAddress = BEACON_ROOTS_ADDRESS
+    (timestampKey, beaconRootKey) = beaconRootStorageIndexes(payload.timestamp.uint64)
+
+  # Verify the timestamp key
+  var r = client.storageAt(precompileAddress, timestampKey, blockNumber)
+  if r.isErr:
+    error "verifyBeaconRootStorage", msg=r.error
+    return false
+
+  if r.get != payload.timestamp.uint64.u256:
+    error "verifyBeaconRootStorage storage 1",
+      expect=payload.timestamp.uint64.u256,
+      get=r.get
+    return false
+
+  # Verify the beacon root key
+  r = client.storageAt(precompileAddress, beaconRootKey, blockNumber)
+  let parentBeaconBlockRoot = timestampToBeaconRoot(payload.timestamp)
+  if parentBeaconBlockRoot != beaconRoot(r.get):
+    error "verifyBeaconRootStorage storage 2",
+      expect=parentBeaconBlockRoot.toHex,
+      get=beaconRoot(r.get).toHex
+    return false
+
+  return true
\ No newline at end of file
diff --git a/hive_integration/nodocker/engine/cancun/step_desc.nim b/hive_integration/nodocker/engine/cancun/step_desc.nim
new file mode 100644
index 000000000..dacbab93f
--- /dev/null
+++ b/hive_integration/nodocker/engine/cancun/step_desc.nim
@@ -0,0 +1,24 @@
+import
+  ../types,
+  ../test_env,
+  ./helpers
+
+type
+  CancunTestContext* = object
+    env*: TestEnv
+    txPool*: TestBlobTxPool
+
+  # Interface to represent a single step in a test vector
+  TestStep* = ref object of RootRef
+    # Executes the step
+
+  # Contains the base spec for all cancun tests.
+  CancunSpec* = ref object of BaseSpec
+    getPayloadDelay*: int # Delay between FcU and GetPayload calls
+    testSequence*: seq[TestStep]
+
+method execute*(step: TestStep, ctx: CancunTestContext): bool {.base.} =
+  true
+
+method description*(step: TestStep): string {.base.} =
+  discard
diff --git a/hive_integration/nodocker/engine/cancun/step_devp2p_peering.nim b/hive_integration/nodocker/engine/cancun/step_devp2p_peering.nim
new file mode 100644
index 000000000..cb635d0a6
--- /dev/null
+++ b/hive_integration/nodocker/engine/cancun/step_devp2p_peering.nim
@@ -0,0 +1,54 @@
+import
+  ./step
+
+# A step that attempts to peer to the client using devp2p, and checks the forkid of the client
+type DevP2PClientPeering struct {
+  # Client index to peer to
+  ClientIndex uint64
+}
+
+func (step DevP2PClientPeering) Execute(t *CancunTestContext) error {
+  # Get client index's enode
+  if step.ClientIndex >= uint64(len(t.TestEngines)) {
+    return error "invalid client index %d", step.ClientIndex)
+  }
+  engine = t.Engines[step.ClientIndex]
+  conn, err = devp2p.PeerEngineClient(engine, env.clMock)
+  if err != nil {
+    return error "error peering engine client: %v", err)
+  }
+  defer conn.Close()
+  info "Connected to client %d, remote public key: %s", step.ClientIndex, conn.RemoteKey())
+
+  # Sleep
+  time.Sleep(1 * time.Second)
+
+  # Timeout value for all requests
+  timeout = 20 * time.Second
+
+  # Send a ping request to verify that we are not immediately disconnected
+  pingReq = &devp2p.Ping{}
+  if size, err = conn.Write(pingReq); err != nil {
+    return errors.Wrap(err, "could not write to conn")
+  else:
+    info "Wrote %d bytes to conn", size)
+  }
+
+  # Finally wait for the pong response
+  msg, err = conn.WaitForResponse(timeout, 0)
+  if err != nil {
+    return errors.Wrap(err, "error waiting for response")
+  }
+  switch msg = msg.(type) {
+  case *devp2p.Pong:
+    info "Received pong response: %v", msg)
+  default:
+    return error "unexpected message type: %T", msg)
+  }
+
+  return nil
+}
+
+func (step DevP2PClientPeering) Description() string {
+  return fmt.Sprintf("DevP2PClientPeering: client %d", step.ClientIndex)
+}
\ No newline at end of file
diff --git a/hive_integration/nodocker/engine/cancun/step_devp2p_pooledtx.nim b/hive_integration/nodocker/engine/cancun/step_devp2p_pooledtx.nim
new file mode 100644
index 000000000..c0bdbab78
--- /dev/null
+++ b/hive_integration/nodocker/engine/cancun/step_devp2p_pooledtx.nim
@@ -0,0 +1,134 @@
+import
+  ./step
+
+# A step that requests a Transaction hash via P2P and expects the correct full blob tx
+type DevP2PRequestPooledTransactionHash struct {
+  # Client index to request the transaction hash from
+  ClientIndex uint64
+  # Transaction Index to request
+  TransactionIndexes []uint64
+  # Wait for a new pooled transaction message before actually requesting the transaction
+  WaitForNewPooledTransaction bool
+}
+
+func (step DevP2PRequestPooledTransactionHash) Execute(t *CancunTestContext) error {
+  # Get client index's enode
+  if step.ClientIndex >= uint64(len(t.TestEngines)) {
+    return error "invalid client index %d", step.ClientIndex)
+  }
+  engine = t.Engines[step.ClientIndex]
+  conn, err = devp2p.PeerEngineClient(engine, env.clMock)
+  if err != nil {
+    return error "error peering engine client: %v", err)
+  }
+  defer conn.Close()
+  info "Connected to client %d, remote public key: %s", step.ClientIndex, conn.RemoteKey())
+
+  var (
+    txHashes = make([]Hash256, len(step.TransactionIndexes))
+    txs      = make([]typ.Transaction, len(step.TransactionIndexes))
+    ok       bool
+  )
+  for i, txIndex = range step.TransactionIndexes {
+    txHashes[i], ok = t.TestBlobTxPool.HashesByIndex[txIndex]
+    if !ok {
+      return error "transaction index %d not found", step.TransactionIndexes[0])
+    }
+    txs[i], ok = t.TestBlobTxPool.transactions[txHashes[i]]
+    if !ok {
+      return error "transaction %s not found", txHashes[i].String())
+    }
+  }
+
+  # Timeout value for all requests
+  timeout = 20 * time.Second
+
+  # Wait for a new pooled transaction message
+  if step.WaitForNewPooledTransaction {
+    msg, err = conn.WaitForResponse(timeout, 0)
+    if err != nil {
+      return errors.Wrap(err, "error waiting for response")
+    }
+    switch msg = msg.(type) {
+    case *devp2p.NewPooledTransactionHashes:
+      if len(msg.Hashes) != len(txHashes) {
+        return error "expected %d hashes, got %d", len(txHashes), len(msg.Hashes))
+      }
+      if len(msg.Types) != len(txHashes) {
+        return error "expected %d types, got %d", len(txHashes), len(msg.Types))
+      }
+      if len(msg.Sizes) != len(txHashes) {
+        return error "expected %d sizes, got %d", len(txHashes), len(msg.Sizes))
+      }
+      for i = 0; i < len(txHashes); i++ {
+        hash, typ, size = msg.Hashes[i], msg.Types[i], msg.Sizes[i]
+        # Get the transaction
+        tx, ok = t.TestBlobTxPool.transactions[hash]
+        if !ok {
+          return error "transaction %s not found", hash.String())
+        }
+
+        if typ != tx.Type() {
+          return error "expected type %d, got %d", tx.Type(), typ)
+        }
+
+        b, err = tx.MarshalBinary()
+        if err != nil {
+          return errors.Wrap(err, "error marshaling transaction")
+        }
+        if size != uint32(len(b)) {
+          return error "expected size %d, got %d", len(b), size)
+        }
+      }
+    default:
+      return error "unexpected message type: %T", msg)
+    }
+  }
+
+  # Send the request for the pooled transactions
+  getTxReq = &devp2p.GetPooledTransactions{
+    RequestId:                   1234,
+    GetPooledTransactionsPacket: txHashes,
+  }
+  if size, err = conn.Write(getTxReq); err != nil {
+    return errors.Wrap(err, "could not write to conn")
+  else:
+    info "Wrote %d bytes to conn", size)
+  }
+
+  # Wait for the response
+  msg, err = conn.WaitForResponse(timeout, getTxReq.RequestId)
+  if err != nil {
+    return errors.Wrap(err, "error waiting for response")
+  }
+  switch msg = msg.(type) {
+  case *devp2p.PooledTransactions:
+    if len(msg.PooledTransactionsBytesPacket) != len(txHashes) {
+      return error "expected %d txs, got %d", len(txHashes), len(msg.PooledTransactionsBytesPacket))
+    }
+    for i, txBytes = range msg.PooledTransactionsBytesPacket {
+      tx = txs[i]
+
+      expBytes, err = tx.MarshalBinary()
+      if err != nil {
+        return errors.Wrap(err, "error marshaling transaction")
+      }
+
+      if len(expBytes) != len(txBytes) {
+        return error "expected size %d, got %d", len(expBytes), len(txBytes))
+      }
+
+      if !bytes.Equal(expBytes, txBytes) {
+        return error "expected tx %#x, got %#x", expBytes, txBytes)
+      }
+
+    }
+  default:
+    return error "unexpected message type: %T", msg)
+  }
+  return nil
+}
+
+func (step DevP2PRequestPooledTransactionHash) Description() string {
+  return fmt.Sprintf("DevP2PRequestPooledTransactionHash: client %d, transaction indexes %v", step.ClientIndex, step.TransactionIndexes)
+}
\ No newline at end of file
diff --git a/hive_integration/nodocker/engine/cancun/step_launch_client.nim b/hive_integration/nodocker/engine/cancun/step_launch_client.nim
new file mode 100644
index 000000000..46be4b385
--- /dev/null
+++ b/hive_integration/nodocker/engine/cancun/step_launch_client.nim
@@ -0,0 +1,47 @@
+import
+  ./step
+
+# A step that launches a new client
+type LaunchClients struct {
+  client.EngineStarter
+  ClientCount              uint64
+  SkipConnectingToBootnode bool
+  SkipAddingToCLMock       bool
+}
+
+func (step LaunchClients) GetClientCount() uint64 {
+  clientCount = step.ClientCount
+  if clientCount == 0 {
+    clientCount = 1
+  }
+  return clientCount
+}
+
+func (step LaunchClients) Execute(t *CancunTestContext) error {
+  # Launch a new client
+  var (
+    client client.EngineClient
+    err    error
+  )
+  clientCount = step.GetClientCount()
+  for i = uint64(0); i < clientCount; i++ {
+    if !step.SkipConnectingToBootnode {
+      client, err = step.StartClient(t.T, t.TestContext, t.Genesis, t.ClientParams, t.ClientFiles, t.Engines[0])
+    else:
+      client, err = step.StartClient(t.T, t.TestContext, t.Genesis, t.ClientParams, t.ClientFiles)
+    }
+    if err != nil {
+      return err
+    }
+    t.Engines = append(t.Engines, client)
+    t.TestEngines = append(t.TestEngines, test.NewTestEngineClient(t.Env, client))
+    if !step.SkipAddingToCLMock {
+      env.clMock.AddEngineClient(client)
+    }
+  }
+  return nil
+}
+
+func (step LaunchClients) Description() string {
+  return fmt.Sprintf("Launch %d new engine client(s)", step.GetClientCount())
+}
diff --git a/hive_integration/nodocker/engine/cancun/step_newpayloads.nim b/hive_integration/nodocker/engine/cancun/step_newpayloads.nim
new file mode 100644
index 000000000..012df10d1
--- /dev/null
+++ b/hive_integration/nodocker/engine/cancun/step_newpayloads.nim
@@ -0,0 +1,409 @@
+import
+  std/strutils,
+  chronicles,
+  ./step_desc,
+  ./helpers,
+  ./customizer,
+  ./blobs,
+  ../engine_client,
+  ../test_env,
+  ../types,
+  ../../../../nimbus/core/eip4844,
+  ../../../../nimbus/common/common
+
+type
+  NewPayloads* = ref object of TestStep
+    # Payload Count
+    payloadCount*: int
+    # Number of blob transactions that are expected to be included in the payload
+    expectedIncludedBlobCount*: int
+    # Blob IDs expected to be found in the payload
+    expectedBlobs*: seq[BlobID]
+    # Delay between FcU and GetPayload calls
+    getPayloadDelay*: int
+    # GetPayload modifier when requesting the new Payload
+    getPayloadCustomizer*: GetPayloadCustomizer
+    # ForkchoiceUpdate modifier when requesting the new Payload
+    fcUOnPayloadRequest*: ForkchoiceUpdatedCustomizer
+    # Extra modifications on NewPayload to potentially generate an invalid payload
+    newPayloadCustomizer*: NewPayloadCustomizer
+    # ForkchoiceUpdate modifier when setting the new payload as head
+    fcUOnHeadSet*: ForkchoiceUpdatedCustomizer
+    # Expected responses on the NewPayload call
+    expectationDescription*: string
+
+func getPayloadCount(step: NewPayloads): int =
+  var payloadCount = step.payloadCount
+  if payloadCount == 0:
+    payloadCount = 1
+  return payloadCount
+
+proc verifyPayload(step: NewPayloads,
+                   com: CommonRef,
+                   client: RpcClient,
+                   blobTxsInPayload: openArray[Transaction],
+                   shouldOverrideBuilder: Option[bool],
+                   payload: ExecutionPayload,
+                   previousPayload = none(ExecutionPayload)): bool =
+
+  var
+    parentExcessBlobGas = 0'u64
+    parentBlobGasUsed   = 0'u64
+
+  if previousPayload.isSome:
+    let prevPayload = previousPayload.get
+    if prevPayload.excessBlobGas.isSome:
+      parentExcessBlobGas = prevPayload.excessBlobGas.get.uint64
+
+    if prevPayload.blobGasUsed.isSome:
+      parentBlobGasUsed = prevPayload.blobGasUsed.get.uint64
+
+  let
+    parent = common.BlockHeader(
+      excessBlobGas: some(parentExcessBlobGas),
+      blobGasUsed: some(parentBlobGasUsed)
+    )
+    expectedExcessBlobGas = calcExcessBlobGas(parent)
+
+  if com.isCancunOrLater(payload.timestamp.EthTime):
+    if payload.excessBlobGas.isNone:
+      error "payload contains nil excessDataGas"
+      return false
+
+    if payload.blobGasUsed.isNone:
+      error "payload contains nil dataGasUsed"
+      return false
+
+    if payload.excessBlobGas.get.uint64 != expectedExcessBlobGas:
+      error "payload contains incorrect excessDataGas",
+        want=expectedExcessBlobGas,
+        have=payload.excessBlobGas.get.uint64
+      return false
+
+    if shouldOverrideBuilder.isNone:
+      error "shouldOverrideBuilder was not included in the getPayload response"
+      return false
+
+    var
+      totalBlobCount = 0
+      expectedBlobGasPrice = getBlobGasPrice(expectedExcessBlobGas)
+
+    for tx in blobTxsInPayload:
+      let blobCount = tx.versionedHashes.len
+      totalBlobCount += blobCount
+
+      # Retrieve receipt from client
+      let r = client.txReceipt(tx.rlpHash)
+      let expectedBlobGasUsed = blobCount.uint64 * GAS_PER_BLOB
+
+      #r.ExpectBlobGasUsed(expectedBlobGasUsed)
+      #r.ExpectBlobGasPrice(expectedBlobGasPrice)
+
+    if totalBlobCount != step.expectedIncludedBlobCount:
+      error "expected blobs in transactions",
+        expect=step.expectedIncludedBlobCount,
+        got=totalBlobCount
+      return false
+
+    if not verifyBeaconRootStorage(client, payload):
+      return false
+
+  else:
+    if payload.excessBlobGas.isSome:
+      error "payload contains non-nil excessDataGas pre-fork"
+      return false
+
+    if payload.blobGasUsed.isSome:
+      error "payload contains non-nil dataGasUsed pre-fork"
+      return false
+
+  return true
+
+proc verifyBlobBundle(step: NewPayloads,
+                      blobDataInPayload: openArray[BlobWrapData],
+                      payload: ExecutionPayload,
+                      blobBundle: BlobsBundleV1): bool =
+
+  if blobBundle.blobs.len != blobBundle.commitments.len or
+      blobBundle.blobs.len != blobBundle.proofs.len:
+    error "unexpected length in blob bundle",
+      blobs=len(blobBundle.blobs),
+      proofs=len(blobBundle.proofs),
+      kzgs=len(blobBundle.commitments)
+    return false
+
+  if len(blobBundle.blobs) != step.expectedIncludedBlobCount:
+    error "expected",
+      expect=step.expectedIncludedBlobCount,
+      get=len(blobBundle.blobs)
+    return false
+
+  # Verify that the calculated amount of blobs in the payload matches the
+  # amount of blobs in the bundle
+  if len(blobDataInPayload) != len(blobBundle.blobs):
+    error "expected blobs in the bundle",
+      expect=len(blobDataInPayload),
+      get=len(blobBundle.blobs)
+    return false
+
+  for i, blobData in blobDataInPayload:
+    let bundleCommitment = blobBundle.commitments[i].bytes
+    let bundleBlob = blobBundle.blobs[i].bytes
+    let bundleProof = blobBundle.proofs[i].bytes
+
+    if bundleCommitment != blobData.commitment:
+      error "KZG mismatch at index of the bundle", index=i
+      return false
+
+    if bundleBlob != blobData.blob:
+      error "blob mismatch at index of the bundle", index=i
+      return false
+
+    if bundleProof != blobData.proof:
+      error "proof mismatch at index of the bundle", index=i
+      return false
+
+  if len(step.expectedBlobs) != 0:
+    # Verify that the blobs in the payload match the expected blobs
+    for expectedBlob in step.expectedBlobs:
+      var found = false
+      for blobData in blobDataInPayload:
+        if not expectedBlob.verifyBlob(blobData.blob):
+          return false
+        else:
+          found = true
+          break
+
+      if not found:
+        error "could not find expected blob", expectedBlob
+        return false
+
+  return true
+
+type
+  Shadow = ref object
+    p: int
+    payloadCount: int
+    prevPayload: ExecutionPayload
+
+method execute*(step: NewPayloads, ctx: CancunTestContext): bool =
+  # Create a new payload
+  # Produce the payload
+  let env = ctx.env
+
+  var originalGetPayloadDelay = env.clMock.payloadProductionClientDelay
+  if step.getPayloadDelay != 0:
+    env.clMock.payloadProductionClientDelay = step.getPayloadDelay
+
+  var shadow = Shadow(
+    payloadCount: step.getPayloadCount(),
+    prevPayload: env.clMock.latestPayloadBuilt
+  )
+
+  for p in 0..<shadow.payloadCount:
+    shadow.p = p
+    let pbRes = env.clMock.produceSingleBlock(BlockProcessCallbacks(
+      onPayloadAttributesGenerated: proc(): bool =
+        #[if step.fcUOnPayloadRequest != nil:
+          var
+            payloadAttributes = env.clMock.latestPayloadAttributes
+            forkchoiceState   = env.clMock.latestForkchoice
+            expectedError     *int
+            expectedStatus    = test.Valid
+            err               error
+          )
+          step.fcUOnPayloadRequest.setEngineAPIVersionResolver(t.ForkConfig)
+          testEngine = t.TestEngine.WithEngineAPIVersionResolver(step.FcUOnPayloadRequest)
+
+          payloadAttributes, err = step.FcUOnPayloadRequest.getPayloadAttributes(payloadAttributes)
+          if err != nil {
+            fatal "Error getting custom payload attributes (payload %d/%d): %v", payload=shadow.p+1, count=shadow.payloadCount, err)
+
+          expectedError, err = step.FcUOnPayloadRequest.getExpectedError()
+          if err != nil {
+            fatal "Error getting custom expected error (payload %d/%d): %v", payload=shadow.p+1, count=shadow.payloadCount, err)
+
+          if step.FcUOnPayloadRequest.getExpectInvalidStatus() {
+            expectedStatus = test.Invalid
+
+
+          r = env.client.ForkchoiceUpdated(&forkchoiceState, payloadAttributes, env.clMock.LatestHeader.Time)
+          r.ExpectationDescription = step.ExpectationDescription
+          if expectedError != nil {
+            r.ExpectErrorCode(*expectedError)
+          else:
+            r.ExpectNoError()
+            r.ExpectPayloadStatus(expectedStatus)
+
+          if r.Response.PayloadID != nil {
+            env.clMock.AddPayloadID(t.Engine, r.Response.PayloadID)
+       ]#
+       return true
+      ,
+      onRequestNextPayload: proc(): bool =
+        # Get the next payload
+        #[if step.GetPayloadCustomizer != nil {
+          var (
+            payloadAttributes = env.clMock.latestPayloadAttributes
+            payloadID         = env.clMock.NextPayloadID
+            expectedError     *int
+            err               error
+          )
+
+          step.GetPayloadCustomizer.setEngineAPIVersionResolver(t.ForkConfig)
+          testEngine = t.TestEngine.WithEngineAPIVersionResolver(step.GetPayloadCustomizer)
+
+          # We are going to sleep twice because there is no way to skip the CL Mock's sleep
+          time.Sleep(time.Duration(step.GetPayloadDelay) * time.Second)
+
+          payloadID, err = step.GetPayloadCustomizer.getPayloadID(payloadID)
+          if err != nil {
+            fatal "Error getting custom payload ID (payload %d/%d): %v", payload=shadow.p+1, count=shadow.payloadCount, err)
+          }
+
+          expectedError, err = step.GetPayloadCustomizer.getExpectedError()
+          if err != nil {
+            fatal "Error getting custom expected error (payload %d/%d): %v", payload=shadow.p+1, count=shadow.payloadCount, err)
+          }
+
+          r = env.client.GetPayload(payloadID, payloadAttributes)
+          r.ExpectationDescription = step.ExpectationDescription
+          if expectedError != nil {
+            r.ExpectErrorCode(*expectedError)
+          else:
+            r.ExpectNoError()
+        ]#
+        return true
+      ,
+      onGetPayload: proc(): bool =
+        # Get the latest blob bundle
+        var
+          blobBundle = env.clMock.latestBlobsBundle
+          payload    = env.clMock.latestPayloadBuilt
+
+        if not env.engine.com.isCancunOrLater(payload.timestamp.EthTime):
+          # Nothing to do
+          return true
+
+        if blobBundle.isNone:
+          fatal "Error getting blobs bundle", payload=shadow.p+1, count=shadow.payloadCount
+          return false
+
+        let res = getBlobDataInPayload(ctx.txPool, payload)
+        if res.isErr:
+          fatal "Error retrieving blob bundle", payload=shadow.p+1, count=shadow.payloadCount, msg=res.error
+          return false
+
+        let blobData = res.get
+
+        if not step.verifyBlobBundle(blobData.data, payload, blobBundle.get):
+          fatal "Error verifying blob bundle",  payload=shadow.p+1, count=shadow.payloadCount
+          return false
+
+        return true
+      ,
+      onNewPayloadBroadcast: proc(): bool =
+        #[if step.NewPayloadCustomizer != nil {
+          # Send a test NewPayload directive with either a modified payload or modifed versioned hashes
+          var (
+            payload        = env.clMock.latestPayloadBuilt
+            r              *test.NewPayloadResponseExpectObject
+            expectedError  *int
+            expectedStatus test.PayloadStatus = test.Valid
+            err            error
+          )
+
+          # Send a custom new payload
+          step.NewPayloadCustomizer.setEngineAPIVersionResolver(t.ForkConfig)
+          testEngine = t.TestEngine.WithEngineAPIVersionResolver(step.NewPayloadCustomizer)
+
+          payload, err = step.NewPayloadCustomizer.customizePayload(payload)
+          if err != nil {
+            fatal "Error customizing payload (payload %d/%d): %v", payload=shadow.p+1, count=shadow.payloadCount, err)
+          }
+          expectedError, err = step.NewPayloadCustomizer.getExpectedError()
+          if err != nil {
+            fatal "Error getting custom expected error (payload %d/%d): %v", payload=shadow.p+1, count=shadow.payloadCount, err)
+          }
+          if step.NewPayloadCustomizer.getExpectInvalidStatus() {
+            expectedStatus = test.Invalid
+          }
+
+          r = env.client.NewPayload(payload)
+          r.ExpectationDescription = step.ExpectationDescription
+          if expectedError != nil {
+            r.ExpectErrorCode(*expectedError)
+          else:
+            r.ExpectNoError()
+            r.ExpectStatus(expectedStatus)
+          }
+        }
+
+        if step.FcUOnHeadSet != nil {
+          var (
+            forkchoiceState api.ForkchoiceStateV1 = env.clMock.latestForkchoice
+            expectedError   *int
+            expectedStatus  test.PayloadStatus = test.Valid
+            err             error
+          )
+          step.FcUOnHeadSet.setEngineAPIVersionResolver(t.ForkConfig)
+          testEngine = t.TestEngine.WithEngineAPIVersionResolver(step.FcUOnHeadSet)
+          expectedError, err = step.FcUOnHeadSet.getExpectedError()
+          if err != nil {
+            fatal "Error getting custom expected error (payload %d/%d): %v", payload=shadow.p+1, count=shadow.payloadCount, err)
+          }
+          if step.FcUOnHeadSet.getExpectInvalidStatus() {
+            expectedStatus = test.Invalid
+          }
+
+          forkchoiceState.HeadBlockHash = env.clMock.latestPayloadBuilt.blockHash
+
+          r = env.client.ForkchoiceUpdated(&forkchoiceState, nil, env.clMock.latestPayloadBuilt.Timestamp)
+          r.ExpectationDescription = step.ExpectationDescription
+          if expectedError != nil {
+            r.ExpectErrorCode(*expectedError)
+          else:
+            r.ExpectNoError()
+            r.ExpectPayloadStatus(expectedStatus)
+        ]#
+        return true
+      ,
+      onForkchoiceBroadcast: proc(): bool =
+        # Verify the transaction receipts on incorporated transactions
+        let payload = env.clMock.latestPayloadBuilt
+
+        let res = getBlobDataInPayload(ctx.txPool, payload)
+        if res.isErr:
+          fatal "Error retrieving blob bundle", payload=shadow.p+1, count=shadow.payloadCount, msg=res.error
+          return false
+
+        let blobData = res.get
+        if not step.verifyPayload(env.engine.com, env.engine.client,
+                   blobData.txs, env.clMock.latestShouldOverrideBuilder,
+                   payload, some(shadow.prevPayload)):
+          fatal "Error verifying payload", payload=shadow.p+1, count=shadow.payloadCount
+          return false
+
+        shadow.prevPayload = env.clMock.latestPayloadBuilt
+        return true
+    ))
+
+    testCond pbRes
+    info "Correctly produced payload", payload=shadow.p+1, count=shadow.payloadCount
+
+  if step.getPayloadDelay != 0:
+    # Restore the original delay
+    env.clMock.payloadProductionClientDelay = originalGetPayloadDelay
+
+  return true
+
+
+method description*(step: NewPayloads): string =
+  #[
+    TODO: Figure out if we need this.
+    if step.VersionedHashes != nil {
+      return fmt.Sprintf("NewPayloads: %d payloads, %d blobs expected, %s", step.getPayloadCount(), step.ExpectedIncludedBlobCount, step.VersionedHashes.Description())
+  ]#
+  "NewPayloads: $1 payloads, $2 blobs expected" % [
+    $step.getPayloadCount(), $step.expectedIncludedBlobCount
+  ]
diff --git a/hive_integration/nodocker/engine/cancun/step_paralel.nim b/hive_integration/nodocker/engine/cancun/step_paralel.nim
new file mode 100644
index 000000000..e221dc3d2
--- /dev/null
+++ b/hive_integration/nodocker/engine/cancun/step_paralel.nim
@@ -0,0 +1,37 @@
+import
+  ./step
+
+# A step that runs two or more steps in parallel
+type ParallelSteps struct {
+  Steps []TestStep
+}
+
+func (step ParallelSteps) Execute(t *CancunTestContext) error {
+  # Run the steps in parallel
+  wg = sync.WaitGroup{}
+  errs = make(chan error, len(step.Steps))
+  for _, s = range step.Steps {
+    wg.Add(1)
+    go func(s TestStep) {
+      defer wg.Done()
+      if err = s.Execute(t); err != nil {
+        errs <- err
+      }
+    }(s)
+  }
+  wg.Wait()
+  close(errs)
+  for err = range errs {
+    return err
+  }
+  return nil
+}
+
+func (step ParallelSteps) Description() string {
+  desc = "ParallelSteps: running steps in parallel:\n"
+  for i, step = range step.Steps {
+    desc += fmt.Sprintf("%d: %s\n", i, step.Description())
+  }
+
+  return desc
+}
\ No newline at end of file
diff --git a/hive_integration/nodocker/engine/cancun/step_sendblobtx.nim b/hive_integration/nodocker/engine/cancun/step_sendblobtx.nim
new file mode 100644
index 000000000..97b1a5739
--- /dev/null
+++ b/hive_integration/nodocker/engine/cancun/step_sendblobtx.nim
@@ -0,0 +1,89 @@
+import
+  std/strutils,
+  eth/common,
+  stint,
+  chronicles,
+  ./step_desc,
+  ./helpers,
+  ./blobs,
+  ../test_env,
+  ../tx_sender,
+  ../../../../nimbus/utils/utils
+
+type
+  # A step that sends multiple new blobs to the client
+  SendBlobTransactions* = ref object of TestStep
+    # Number of blob transactions to send before this block's GetPayload request
+    transactionCount*: int
+    # Blobs per transaction
+    blobsPerTransaction*: int
+    # Max Data Gas Cost for every blob transaction
+    blobTransactionMaxBlobGasCost*: UInt256
+    # Gas Fee Cap for every blob transaction
+    blobTransactionGasFeeCap*: GasInt
+    # Gas Tip Cap for every blob transaction
+    blobTransactionGasTipCap*: GasInt
+    # Replace transactions
+    replaceTransactions*: bool
+    # Skip verification of retrieving the tx from node
+    skipVerificationFromNode*: bool
+    # Account index to send the blob transactions from
+    accountIndex*: int
+    # Client index to send the blob transactions to
+    clientIndex*: int
+
+func getBlobsPerTransaction(step: SendBlobTransactions): int =
+  var blobCountPerTx = step.blobsPerTransaction
+  if blobCountPerTx == 0:
+    blobCountPerTx = 1
+  return blobCountPerTx
+
+method execute*(step: SendBlobTransactions, ctx: CancunTestContext): bool =
+  # Send a blob transaction
+  let blobCountPerTx = step.getBlobsPerTransaction()
+
+  if step.clientIndex >= ctx.env.numEngines:
+    error "invalid client index", index=step.clientIndex
+    return false
+
+  let engine = ctx.env.engines(step.clientIndex)
+  #  Send the blob transactions
+  for _ in 0..<step.transactionCount:
+    let tc = BlobTx(
+      recipient:  some(DATAHASH_START_ADDRESS),
+      gasLimit:   100000.GasInt,
+      gasTip:     step.blobTransactionGasTipCap,
+      gasFee:     step.blobTransactionGasFeeCap,
+      blobGasFee: step.blobTransactionMaxBlobGasCost,
+      blobCount:  blobCountPerTx,
+      blobID:     ctx.txPool.currentBlobID,
+    )
+
+    let sender = ctx.env.accounts(step.accountIndex)
+    let res = if step.replaceTransactions:
+                ctx.env.replaceTx(sender, engine, tc)
+              else:
+                ctx.env.sendTx(sender, engine, tc)
+
+    if res.isErr:
+      return false
+
+    let blobTx = res.get
+    if not step.skipVerificationFromNode:
+      let r = verifyTransactionFromNode(engine.client, blobTx)
+      if r.isErr:
+        error "verify tx from node", msg=r.error
+        return false
+
+    let txHash = rlpHash(blobTx)
+    ctx.txPool.addBlobTransaction(blobTx)
+    ctx.txPool.hashesByIndex[ctx.txPool.currentTxIndex] = txHash
+    ctx.txPool.currentTxIndex += 1
+    info "Sent blob transaction", txHash=txHash.short
+    ctx.txPool.currentBlobID += BlobID(blobCountPerTx)
+
+  return true
+
+method description*(step: SendBlobTransactions): string =
+  "SendBlobTransactions: $1 transactions, $2 blobs each, $3 max data gas fee" % [
+    $step.transactionCount, $step.getBlobsPerTransaction(), $step.blobTransactionMaxBlobGasCost]
diff --git a/hive_integration/nodocker/engine/cancun/step_sendmodpayload.nim b/hive_integration/nodocker/engine/cancun/step_sendmodpayload.nim
new file mode 100644
index 000000000..3ccf964ac
--- /dev/null
+++ b/hive_integration/nodocker/engine/cancun/step_sendmodpayload.nim
@@ -0,0 +1,63 @@
+# Send a modified version of the latest payload produced using NewPayloadV3
+type SendModifiedLatestPayload struct {
+  ClientID             uint64
+  NewPayloadCustomizer helper.NewPayloadCustomizer
+}
+
+method execute*(step: SendModifiedLatestPayload, ctx: CancunTestContext): bool =
+  # Get the latest payload
+  var (
+    payload                           = &env.clMock.latestPayloadBuilt
+    expectedError  *int               = nil
+    expectedStatus test.PayloadStatus = test.Valid
+    err            error              = nil
+  )
+  if payload == nil {
+    return error "TEST-FAIL: no payload available")
+  }
+  if env.clMock.LatestBlobBundle == nil {
+    return error "TEST-FAIL: no blob bundle available")
+  }
+  if step.NewPayloadCustomizer == nil {
+    return error "TEST-FAIL: no payload customizer available")
+  }
+
+  # Send a custom new payload
+  step.NewPayloadCustomizer.setEngineAPIVersionResolver(t.ForkConfig)
+  payload, err = step.NewPayloadCustomizer.customizePayload(payload)
+  if err != nil {
+    fatal "Error customizing payload: %v", err)
+  }
+  expectedError, err = step.NewPayloadCustomizer.getExpectedError()
+  if err != nil {
+    fatal "Error getting custom expected error: %v", err)
+  }
+  if step.NewPayloadCustomizer.getExpectInvalidStatus() {
+    expectedStatus = test.Invalid
+  }
+
+  # Send the payload
+  if step.ClientID >= uint64(len(t.TestEngines)) {
+    return error "invalid client index %d", step.ClientID)
+  }
+  testEngine = t.TestEngines[step.ClientID].WithEngineAPIVersionResolver(step.NewPayloadCustomizer)
+  r = env.client.NewPayload(payload)
+  if expectedError != nil {
+    r.ExpectErrorCode(*expectedError)
+  else:
+    r.ExpectStatus(expectedStatus)
+  }
+  return nil
+}
+
+method description*(step: SendModifiedLatestPayload): string =
+  desc = fmt.Sprintf("SendModifiedLatestPayload: client %d, expected invalid=%T, ", step.ClientID, step.NewPayloadCustomizer.getExpectInvalidStatus())
+  /*
+    TODO: Figure out if we need this.
+    if step.VersionedHashes != nil {
+      desc += step.VersionedHashes.Description()
+    }
+  */
+
+  return desc
+}
\ No newline at end of file
diff --git a/hive_integration/nodocker/engine/cancun_tests.nim b/hive_integration/nodocker/engine/cancun_tests.nim
new file mode 100644
index 000000000..f66a1c7c7
--- /dev/null
+++ b/hive_integration/nodocker/engine/cancun_tests.nim
@@ -0,0 +1,1992 @@
+import
+  std/tables,
+  chronos,
+  chronicles,
+  stew/byteutils,
+  ./types,
+  ./base_spec,
+  ./test_env,
+  ./clmock,
+  ./cancun/step_desc,
+  ./cancun/helpers,
+  ./cancun/blobs,
+  ../../nimbus/constants,
+  ../../nimbus/common/chain_config
+
+import
+  ./cancun/step_newpayloads,
+  ./cancun/step_sendblobtx
+
+# Precalculate the first data gas cost increase
+const
+  DATA_GAS_COST_INCREMENT_EXCEED_BLOBS = getMinExcessBlobsForBlobGasPrice(2)
+  TARGET_BLOBS_PER_BLOCK = int(TARGET_BLOB_GAS_PER_BLOCK div GAS_PER_BLOB)
+
+proc getGenesis(param: NetworkParams) =
+  # Add bytecode pre deploy to the EIP-4788 address.
+  param.genesis.alloc[BEACON_ROOTS_ADDRESS] = GenesisAccount(
+    balance: 0.u256,
+    nonce:   1,
+    code:    hexToSeqByte("3373fffffffffffffffffffffffffffffffffffffffe14604d57602036146024575f5ffd5b5f35801560495762001fff810690815414603c575f5ffd5b62001fff01545f5260205ff35b5f5ffd5b62001fff42064281555f359062001fff015500"),
+  )
+
+# Execution specification reference:
+# https:#github.com/ethereum/execution-apis/blob/main/src/engine/cancun.md
+proc specExecute(ws: BaseSpec): bool =
+  ws.mainFork = ForkCancun
+  let
+    cs = CancunSpec(ws)
+    conf = envConfig(ws.getForkConfig())
+
+  getGenesis(conf.networkParams)
+  let env  = TestEnv.new(conf)
+  env.engine.setRealTTD(0)
+  env.setupCLMock()
+  ws.configureCLMock(env.clMock)
+
+  testCond waitFor env.clMock.waitForTTD()
+
+  let blobTestCtx = CancunTestContext(
+    env: env,
+    txPool: TestBlobTxPool(),
+  )
+
+  if cs.getPayloadDelay != 0:
+    env.clMock.payloadProductionClientDelay = cs.getPayloadDelay
+
+  result = true
+  for stepId, step in cs.testSequence:
+    echo "INFO: Executing step", stepId+1, ": ", step.description()
+    if not step.execute(blobTestCtx):
+      fatal "FAIL: Error executing", step=stepId+1
+      result = false
+      break
+
+  env.close()
+
+# List of all blob tests
+let cancunTestList* = [
+  TestDesc(
+    name: "Blob Transactions On Block 1, Shanghai Genesis",
+    about: """
+      Tests the Cancun fork since Block 1.
+
+      Verifications performed:
+      - Correct implementation of Engine API changes for Cancun:
+        - engine_newPayloadV3, engine_forkchoiceUpdatedV3, engine_getPayloadV3
+      - Correct implementation of EIP-4844:
+        - Blob transaction ordering and inclusion
+        - Blob transaction blob gas cost checks
+        - Verify Blob bundle on built payload
+      - Eth RPC changes for Cancun:
+        - Blob fields in eth_getBlockByNumber
+        - Beacon root in eth_getBlockByNumber
+        - Blob fields in transaction receipts from eth_getTransactionReceipt
+      """,
+    run: specExecute,
+    spec: CancunSpec(
+      forkHeight: 1,
+      testSequence: @[
+        # We are starting at Shanghai genesis so send a couple payloads to reach the fork
+        NewPayloads().TestStep,
+
+        # First, we send a couple of blob transactions on genesis,
+        # with enough data gas cost to make sure they are included in the first block.
+        SendBlobTransactions(
+          transactionCount:              TARGET_BLOBS_PER_BLOCK,
+          blobTransactionMaxBlobGasCost: u256(1),
+        ),
+
+        # We create the first payload, and verify that the blob transactions
+        # are included in the payload.
+        # We also verify that the blob transactions are included in the blobs bundle.
+        #[NewPayloads(
+          expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+          expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+        ),
+
+        # Try to increase the data gas cost of the blob transactions
+        # by maxing out the number of blobs for the next payloads.
+        SendBlobTransactions(
+          transactionCount:              DATA_GAS_COST_INCREMENT_EXCEED_BLOBS div (MAX_BLOBS_PER_BLOCK-TARGET_BLOBS_PER_BLOCK) + 1,
+          blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+          blobTransactionMaxBlobGasCost: u256(1),
+        ),
+
+        # Next payloads will have max data blobs each
+        NewPayloads(
+          payloadCount:              DATA_GAS_COST_INCREMENT_EXCEED_BLOBS div (MAX_BLOBS_PER_BLOCK - TARGET_BLOBS_PER_BLOCK),
+          expectedIncludedBlobCount: MAX_BLOBS_PER_BLOCK,
+        ),
+
+        # But there will be an empty payload, since the data gas cost increased
+        # and the last blob transaction was not included.
+        NewPayloads(
+          expectedIncludedBlobCount: 0,
+        ),
+
+        # But it will be included in the next payload
+        NewPayloads(
+          expectedIncludedBlobCount: MAX_BLOBS_PER_BLOCK,
+        ),]#
+      ]
+    )
+  ),
+]
+
+#[
+  TestDesc(
+    spec: CancunSpec(
+
+
+      name: "Blob Transactions On Block 1, Cancun Genesis",
+      about: """
+      Tests the Cancun fork since genesis.
+
+      Verifications performed:
+      * See Blob Transactions On Block 1, Shanghai Genesis
+      """,
+      mainFork: Cancun,
+    ),
+
+    testSequence: @[
+      NewPayloads(), # Create a single empty payload to push the client through the fork.
+      # First, we send a couple of blob transactions on genesis,
+      # with enough data gas cost to make sure they are included in the first block.
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+
+      # We create the first payload, and verify that the blob transactions
+      # are included in the payload.
+      # We also verify that the blob transactions are included in the blobs bundle.
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+      ),
+
+      # Try to increase the data gas cost of the blob transactions
+      # by maxing out the number of blobs for the next payloads.
+      SendBlobTransactions(
+        transactionCount:              DATA_GAS_COST_INCREMENT_EXCEED_BLOBS/(MAX_BLOBS_PER_BLOCK-TARGET_BLOBS_PER_BLOCK) + 1,
+        blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+
+      # Next payloads will have max data blobs each
+      NewPayloads(
+        payloadCount:              DATA_GAS_COST_INCREMENT_EXCEED_BLOBS / (MAX_BLOBS_PER_BLOCK - TARGET_BLOBS_PER_BLOCK),
+        expectedIncludedBlobCount: MAX_BLOBS_PER_BLOCK,
+      ),
+
+      # But there will be an empty payload, since the data gas cost increased
+      # and the last blob transaction was not included.
+      NewPayloads(
+        expectedIncludedBlobCount: 0,
+      ),
+
+      # But it will be included in the next payload
+      NewPayloads(
+        expectedIncludedBlobCount: MAX_BLOBS_PER_BLOCK,
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+
+      name: "Blob Transaction Ordering, Single Account",
+      about: """
+      Send N blob transactions with MAX_BLOBS_PER_BLOCK-1 blobs each,
+      using account A.
+      Using same account, and an increased nonce from the previously sent
+      transactions, send N blob transactions with 1 blob each.
+      Verify that the payloads are created with the correct ordering:
+       - The first payloads must include the first N blob transactions
+       - The last payloads must include the last single-blob transactions
+      All transactions have sufficient data gas price to be included any
+      of the payloads.
+      """,
+      mainFork: Cancun,
+    ),
+
+    testSequence: @[
+      # First send the MAX_BLOBS_PER_BLOCK-1 blob transactions.
+      SendBlobTransactions(
+        transactionCount:              5,
+        blobsPerTransaction:           MAX_BLOBS_PER_BLOCK - 1,
+        blobTransactionMaxBlobGasCost: u256(100),
+      ),
+      # Then send the single-blob transactions
+      SendBlobTransactions(
+        transactionCount:              MAX_BLOBS_PER_BLOCK + 1,
+        blobsPerTransaction:           1,
+        blobTransactionMaxBlobGasCost: u256(100),
+      ),
+
+      # First four payloads have MAX_BLOBS_PER_BLOCK-1 blobs each
+      NewPayloads(
+        payloadCount:              4,
+        expectedIncludedBlobCount: MAX_BLOBS_PER_BLOCK - 1,
+      ),
+
+      # The rest of the payloads have full blobs
+      NewPayloads(
+        payloadCount:              2,
+        expectedIncludedBlobCount: MAX_BLOBS_PER_BLOCK,
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+
+      name: "Blob Transaction Ordering, Single Account 2",
+      about: """
+      Send N blob transactions with MAX_BLOBS_PER_BLOCK-1 blobs each,
+      using account A.
+      Using same account, and an increased nonce from the previously sent
+      transactions, send a single 2-blob transaction, and send N blob
+      transactions with 1 blob each.
+      Verify that the payloads are created with the correct ordering:
+       - The first payloads must include the first N blob transactions
+       - The last payloads must include the rest of the transactions
+      All transactions have sufficient data gas price to be included any
+      of the payloads.
+      """,
+      mainFork: Cancun,
+    ),
+
+    testSequence: @[
+      # First send the MAX_BLOBS_PER_BLOCK-1 blob transactions.
+      SendBlobTransactions(
+        transactionCount:              5,
+        blobsPerTransaction:           MAX_BLOBS_PER_BLOCK - 1,
+        blobTransactionMaxBlobGasCost: u256(100),
+      ),
+
+      # Then send the dual-blob transaction
+      SendBlobTransactions(
+        transactionCount:              1,
+        blobsPerTransaction:           2,
+        blobTransactionMaxBlobGasCost: u256(100),
+      ),
+
+      # Then send the single-blob transactions
+      SendBlobTransactions(
+        transactionCount:              MAX_BLOBS_PER_BLOCK - 2,
+        blobsPerTransaction:           1,
+        blobTransactionMaxBlobGasCost: u256(100),
+      ),
+
+      # First five payloads have MAX_BLOBS_PER_BLOCK-1 blobs each
+      NewPayloads(
+        payloadCount:              5,
+        expectedIncludedBlobCount: MAX_BLOBS_PER_BLOCK - 1,
+      ),
+
+      # The rest of the payloads have full blobs
+      NewPayloads(
+        payloadCount:              1,
+        expectedIncludedBlobCount: MAX_BLOBS_PER_BLOCK,
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+
+      name: "Blob Transaction Ordering, Multiple Accounts",
+      about: """
+      Send N blob transactions with MAX_BLOBS_PER_BLOCK-1 blobs each,
+      using account A.
+      Send N blob transactions with 1 blob each from account B.
+      Verify that the payloads are created with the correct ordering:
+       - All payloads must have full blobs.
+      All transactions have sufficient data gas price to be included any
+      of the payloads.
+      """,
+      mainFork: Cancun,
+    ),
+
+    testSequence: @[
+      # First send the MAX_BLOBS_PER_BLOCK-1 blob transactions from
+      # account A.
+      SendBlobTransactions(
+        transactionCount:              5,
+        blobsPerTransaction:           MAX_BLOBS_PER_BLOCK - 1,
+        blobTransactionMaxBlobGasCost: u256(100),
+        AccountIndex:                  0,
+      ),
+      # Then send the single-blob transactions from account B
+      SendBlobTransactions(
+        transactionCount:              5,
+        blobsPerTransaction:           1,
+        blobTransactionMaxBlobGasCost: u256(100),
+        AccountIndex:                  1,
+      ),
+
+      # All payloads have full blobs
+      NewPayloads(
+        payloadCount:              5,
+        expectedIncludedBlobCount: MAX_BLOBS_PER_BLOCK,
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+
+      name: "Blob Transaction Ordering, Multiple Clients",
+      about: """
+      Send N blob transactions with MAX_BLOBS_PER_BLOCK-1 blobs each,
+      using account A, to client A.
+      Send N blob transactions with 1 blob each from account B, to client
+      B.
+      Verify that the payloads are created with the correct ordering:
+       - All payloads must have full blobs.
+      All transactions have sufficient data gas price to be included any
+      of the payloads.
+      """,
+      mainFork: Cancun,
+    ),
+
+    testSequence: @[
+      # Start a secondary client to also receive blob transactions
+      LaunchClients{
+        EngineStarter: hive_rpc.HiveRPCEngineStarter{),
+        # Skip adding the second client to the CL Mock to guarantee
+        # that all payloads are produced by client A.
+        # This is done to not have client B prioritizing single-blob
+        # transactions to fill one single payload.
+        SkipAddingToCLMock: true,
+      ),
+
+      # Create a block without any blobs to get past genesis
+      NewPayloads(
+        payloadCount:              1,
+        expectedIncludedBlobCount: 0,
+      ),
+
+      # First send the MAX_BLOBS_PER_BLOCK-1 blob transactions from
+      # account A, to client A.
+      SendBlobTransactions(
+        transactionCount:              5,
+        blobsPerTransaction:           MAX_BLOBS_PER_BLOCK - 1,
+        blobTransactionMaxBlobGasCost: u256(120),
+        AccountIndex:                  0,
+        ClientIndex:                   0,
+      ),
+      # Then send the single-blob transactions from account B, to client
+      # B.
+      SendBlobTransactions(
+        transactionCount:              5,
+        blobsPerTransaction:           1,
+        blobTransactionMaxBlobGasCost: u256(100),
+        AccountIndex:                  1,
+        ClientIndex:                   1,
+      ),
+
+      # All payloads have full blobs
+      NewPayloads(
+        payloadCount:              5,
+        expectedIncludedBlobCount: MAX_BLOBS_PER_BLOCK,
+        # Wait a bit more on before requesting the built payload from the client
+        GetPayloadDelay: 2,
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+
+      name: "Replace Blob Transactions",
+      about: """
+      Test sending multiple blob transactions with the same nonce, but
+      higher gas tip so the transaction is replaced.
+      """,
+      mainFork: Cancun,
+    ),
+
+    testSequence: @[
+      # Send multiple blob transactions with the same nonce.
+      SendBlobTransactions( # Blob ID 0
+        transactionCount:              1,
+        blobTransactionMaxBlobGasCost: u256(1),
+        BlobTransactionGasFeeCap:      u256(1e9),
+        BlobTransactionGasTipCap:      u256(1e9),
+      ),
+      SendBlobTransactions( # Blob ID 1
+        transactionCount:              1,
+        blobTransactionMaxBlobGasCost: u256(1e2),
+        BlobTransactionGasFeeCap:      u256(1e10),
+        BlobTransactionGasTipCap:      u256(1e10),
+        ReplaceTransactions:           true,
+      ),
+      SendBlobTransactions( # Blob ID 2
+        transactionCount:              1,
+        blobTransactionMaxBlobGasCost: u256(1e3),
+        BlobTransactionGasFeeCap:      u256(1e11),
+        BlobTransactionGasTipCap:      u256(1e11),
+        ReplaceTransactions:           true,
+      ),
+      SendBlobTransactions( # Blob ID 3
+        transactionCount:              1,
+        blobTransactionMaxBlobGasCost: u256(1e4),
+        BlobTransactionGasFeeCap:      u256(1e12),
+        BlobTransactionGasTipCap:      u256(1e12),
+        ReplaceTransactions:           true,
+      ),
+
+      # We create the first payload, which must contain the blob tx
+      # with the higher tip.
+      NewPayloads(
+        expectedIncludedBlobCount: 1,
+        expectedBlobs:             []helper.BlobID{3),
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+
+      name: "Parallel Blob Transactions",
+      about: """
+      Test sending multiple blob transactions in parallel from different accounts.
+
+      Verify that a payload is created with the maximum number of blobs.
+      """,
+      mainFork: Cancun,
+    ),
+
+    testSequence: @[
+      # Send multiple blob transactions with the same nonce.
+      ParallelSteps{
+        Steps: []TestStep{
+          SendBlobTransactions(
+            transactionCount:              5,
+            blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+            blobTransactionMaxBlobGasCost: u256(100),
+            AccountIndex:                  0,
+          ),
+          SendBlobTransactions(
+            transactionCount:              5,
+            blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+            blobTransactionMaxBlobGasCost: u256(100),
+            AccountIndex:                  1,
+          ),
+          SendBlobTransactions(
+            transactionCount:              5,
+            blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+            blobTransactionMaxBlobGasCost: u256(100),
+            AccountIndex:                  2,
+          ),
+          SendBlobTransactions(
+            transactionCount:              5,
+            blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+            blobTransactionMaxBlobGasCost: u256(100),
+            AccountIndex:                  3,
+          ),
+          SendBlobTransactions(
+            transactionCount:              5,
+            blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+            blobTransactionMaxBlobGasCost: u256(100),
+            AccountIndex:                  4,
+          ),
+          SendBlobTransactions(
+            transactionCount:              5,
+            blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+            blobTransactionMaxBlobGasCost: u256(100),
+            AccountIndex:                  5,
+          ),
+          SendBlobTransactions(
+            transactionCount:              5,
+            blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+            blobTransactionMaxBlobGasCost: u256(100),
+            AccountIndex:                  6,
+          ),
+          SendBlobTransactions(
+            transactionCount:              5,
+            blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+            blobTransactionMaxBlobGasCost: u256(100),
+            AccountIndex:                  7,
+          ),
+          SendBlobTransactions(
+            transactionCount:              5,
+            blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+            blobTransactionMaxBlobGasCost: u256(100),
+            AccountIndex:                  8,
+          ),
+          SendBlobTransactions(
+            transactionCount:              5,
+            blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+            blobTransactionMaxBlobGasCost: u256(100),
+            AccountIndex:                  9,
+          ),
+        ),
+      ),
+
+      # We create the first payload, which is guaranteed to have the first MAX_BLOBS_PER_BLOCK blobs.
+      NewPayloads(
+        expectedIncludedBlobCount: MAX_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, MAX_BLOBS_PER_BLOCK),
+      ),
+    ),
+  ),
+
+  # ForkchoiceUpdatedV3 before cancun
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "ForkchoiceUpdatedV3 Set Head to Shanghai Payload, Nil Payload Attributes",
+      about: """
+      Test sending ForkchoiceUpdatedV3 to set the head of the chain to a Shanghai payload:
+      - Send NewPayloadV2 with Shanghai payload on block 1
+      - Use ForkchoiceUpdatedV3 to set the head to the payload, with nil payload attributes
+
+      Verify that client returns no error.
+      """,
+      mainFork:   Cancun,
+      forkHeight: 2,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        FcUOnHeadSet: &helper.UpgradeForkchoiceUpdatedVersion{
+          ForkchoiceUpdatedCustomizer: &helper.BaseForkchoiceUpdatedCustomizer{),
+        ),
+        ExpectationDescription: """
+        ForkchoiceUpdatedV3 before Cancun returns no error without payload attributes
+        """,
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "ForkchoiceUpdatedV3 To Request Shanghai Payload, Nil Beacon Root",
+      about: """
+      Test sending ForkchoiceUpdatedV3 to request a Shanghai payload:
+      - Payload Attributes uses Shanghai timestamp
+      - Payload Attributes' Beacon Root is nil
+
+      Verify that client returns INVALID_PARAMS_ERROR.
+      """,
+      mainFork:   Cancun,
+      forkHeight: 2,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        FcUOnPayloadRequest: &helper.UpgradeForkchoiceUpdatedVersion{
+          ForkchoiceUpdatedCustomizer: &helper.BaseForkchoiceUpdatedCustomizer{
+            ExpectedError: globals.INVALID_PARAMS_ERROR,
+          ),
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        ForkchoiceUpdatedV3 before Cancun with any nil field must return INVALID_PARAMS_ERROR (code %d)
+        """, *globals.INVALID_PARAMS_ERROR),
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "ForkchoiceUpdatedV3 To Request Shanghai Payload, Zero Beacon Root",
+      about: """
+      Test sending ForkchoiceUpdatedV3 to request a Shanghai payload:
+      - Payload Attributes uses Shanghai timestamp
+      - Payload Attributes' Beacon Root zero
+
+      Verify that client returns UNSUPPORTED_FORK_ERROR.
+      """,
+      mainFork:   Cancun,
+      forkHeight: 2,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        FcUOnPayloadRequest: &helper.UpgradeForkchoiceUpdatedVersion{
+          ForkchoiceUpdatedCustomizer: &helper.BaseForkchoiceUpdatedCustomizer{
+            PayloadAttributesCustomizer: &helper.BasePayloadAttributesCustomizer{
+              BeaconRoot: &(common.Hash{}),
+            ),
+            ExpectedError: globals.UNSUPPORTED_FORK_ERROR,
+          ),
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        ForkchoiceUpdatedV3 before Cancun with beacon root must return UNSUPPORTED_FORK_ERROR (code %d)
+        """, *globals.UNSUPPORTED_FORK_ERROR),
+      ),
+    ),
+  ),
+
+  # ForkchoiceUpdatedV2 before cancun with beacon root
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "ForkchoiceUpdatedV2 To Request Shanghai Payload, Zero Beacon Root",
+      about: """
+      Test sending ForkchoiceUpdatedV2 to request a Cancun payload:
+      - Payload Attributes uses Shanghai timestamp
+      - Payload Attributes' Beacon Root zero
+
+      Verify that client returns INVALID_PARAMS_ERROR.
+      """,
+      mainFork:   Cancun,
+      forkHeight: 1,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        FcUOnPayloadRequest: &helper.DowngradeForkchoiceUpdatedVersion{
+          ForkchoiceUpdatedCustomizer: &helper.BaseForkchoiceUpdatedCustomizer{
+            PayloadAttributesCustomizer: &helper.BasePayloadAttributesCustomizer{
+              BeaconRoot: &(common.Hash{}),
+            ),
+            ExpectedError: globals.INVALID_PARAMS_ERROR,
+          ),
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        ForkchoiceUpdatedV2 before Cancun with beacon root field must return INVALID_PARAMS_ERROR (code %d)
+        """, *globals.INVALID_PARAMS_ERROR),
+      ),
+    ),
+  ),
+
+  # ForkchoiceUpdatedV2 after cancun
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "ForkchoiceUpdatedV2 To Request Cancun Payload, Zero Beacon Root",
+      about: """
+      Test sending ForkchoiceUpdatedV2 to request a Cancun payload:
+      - Payload Attributes uses Cancun timestamp
+      - Payload Attributes' Beacon Root zero
+
+      Verify that client returns INVALID_PARAMS_ERROR.
+      """,
+      mainFork:   Cancun,
+      forkHeight: 1,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        FcUOnPayloadRequest: &helper.DowngradeForkchoiceUpdatedVersion{
+          ForkchoiceUpdatedCustomizer: &helper.BaseForkchoiceUpdatedCustomizer{
+            ExpectedError: globals.INVALID_PARAMS_ERROR,
+          ),
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        ForkchoiceUpdatedV2 after Cancun with beacon root field must return INVALID_PARAMS_ERROR (code %d)
+        """, *globals.INVALID_PARAMS_ERROR),
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "ForkchoiceUpdatedV2 To Request Cancun Payload, Nil Beacon Root",
+      about: """
+      Test sending ForkchoiceUpdatedV2 to request a Cancun payload:
+      - Payload Attributes uses Cancun timestamp
+      - Payload Attributes' Beacon Root nil (not provided)
+
+      Verify that client returns UNSUPPORTED_FORK_ERROR.
+      """,
+      mainFork:   Cancun,
+      forkHeight: 1,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        FcUOnPayloadRequest: &helper.DowngradeForkchoiceUpdatedVersion{
+          ForkchoiceUpdatedCustomizer: &helper.BaseForkchoiceUpdatedCustomizer{
+            PayloadAttributesCustomizer: &helper.BasePayloadAttributesCustomizer{
+              RemoveBeaconRoot: true,
+            ),
+            ExpectedError: globals.UNSUPPORTED_FORK_ERROR,
+          ),
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        ForkchoiceUpdatedV2 after Cancun must return UNSUPPORTED_FORK_ERROR (code %d)
+        """, *globals.UNSUPPORTED_FORK_ERROR),
+      ),
+    ),
+  ),
+
+  # ForkchoiceUpdatedV3 with modified BeaconRoot Attribute
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "ForkchoiceUpdatedV3 Modifies Payload ID on Different Beacon Root",
+      about: """
+      Test requesting a Cancun Payload using ForkchoiceUpdatedV3 twice with the beacon root
+      payload attribute as the only change between requests and verify that the payload ID is
+      different.
+      """,
+      mainFork: Cancun,
+    ),
+
+    testSequence: @[
+      SendBlobTransactions(
+        transactionCount:              1,
+        blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(100),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: MAX_BLOBS_PER_BLOCK,
+        FcUOnPayloadRequest: &helper.BaseForkchoiceUpdatedCustomizer{
+          PayloadAttributesCustomizer: &helper.BasePayloadAttributesCustomizer{
+            BeaconRoot: &(common.Hash{}),
+          ),
+        ),
+      ),
+      SendBlobTransactions(
+        transactionCount:              1,
+        blobsPerTransaction:           MAX_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(100),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: MAX_BLOBS_PER_BLOCK,
+        FcUOnPayloadRequest: &helper.BaseForkchoiceUpdatedCustomizer{
+          PayloadAttributesCustomizer: &helper.BasePayloadAttributesCustomizer{
+            BeaconRoot: &(common.Hash{1}),
+          ),
+        ),
+      ),
+    ),
+  ),
+
+  # GetPayloadV3 Before Cancun, Negative Tests
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "GetPayloadV3 To Request Shanghai Payload",
+      about: """
+      Test requesting a Shanghai PayloadID using GetPayloadV3.
+      Verify that client returns UNSUPPORTED_FORK_ERROR.
+      """,
+      mainFork:   Cancun,
+      forkHeight: 2,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        GetPayloadCustomizer: &helper.UpgradeGetPayloadVersion{
+          GetPayloadCustomizer: &helper.BaseGetPayloadCustomizer{
+            ExpectedError: globals.UNSUPPORTED_FORK_ERROR,
+          ),
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        GetPayloadV3 To Request Shanghai Payload must return UNSUPPORTED_FORK_ERROR (code %d)
+        """, *globals.UNSUPPORTED_FORK_ERROR),
+      ),
+    ),
+  ),
+
+  # GetPayloadV2 After Cancun, Negative Tests
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "GetPayloadV2 To Request Cancun Payload",
+      about: """
+      Test requesting a Cancun PayloadID using GetPayloadV2.
+      Verify that client returns UNSUPPORTED_FORK_ERROR.
+      """,
+      mainFork:   Cancun,
+      forkHeight: 1,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        GetPayloadCustomizer: &helper.DowngradeGetPayloadVersion{
+          GetPayloadCustomizer: &helper.BaseGetPayloadCustomizer{
+            ExpectedError: globals.UNSUPPORTED_FORK_ERROR,
+          ),
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        GetPayloadV2 To Request Cancun Payload must return UNSUPPORTED_FORK_ERROR (code %d)
+        """, *globals.UNSUPPORTED_FORK_ERROR),
+      ),
+    ),
+  ),
+
+  # NewPayloadV3 Before Cancun, Negative Tests
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Before Cancun, Nil Data Fields, Nil Versioned Hashes, Nil Beacon Root",
+      about: """
+      Test sending NewPayloadV3 Before Cancun with:
+      - nil ExcessBlobGas
+      - nil BlobGasUsed
+      - nil Versioned Hashes Array
+      - nil Beacon Root
+
+      Verify that client returns INVALID_PARAMS_ERROR
+      """,
+      mainFork:   Cancun,
+      forkHeight: 2,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        NewPayloadCustomizer: &helper.UpgradeNewPayloadVersion{
+          NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+            payloadCustomizer: CustomPayloadData(
+              VersionedHashesCustomizer: &VersionedHashes{
+                Blobs: nil,
+              ),
+            ),
+            ExpectedError: globals.INVALID_PARAMS_ERROR,
+          ),
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        NewPayloadV3 before Cancun with any nil field must return INVALID_PARAMS_ERROR (code %d)
+        """, *globals.INVALID_PARAMS_ERROR),
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Before Cancun, Nil ExcessBlobGas, 0x00 BlobGasUsed, Nil Versioned Hashes, Nil Beacon Root",
+      about: """
+      Test sending NewPayloadV3 Before Cancun with:
+      - nil ExcessBlobGas
+      - 0x00 BlobGasUsed
+      - nil Versioned Hashes Array
+      - nil Beacon Root
+      """,
+      mainFork:   Cancun,
+      forkHeight: 2,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        NewPayloadCustomizer: &helper.UpgradeNewPayloadVersion{
+          NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+            payloadCustomizer: CustomPayloadData(
+              BlobGasUsed: pUint64(0),
+            ),
+            ExpectedError: globals.INVALID_PARAMS_ERROR,
+          ),
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        NewPayloadV3 before Cancun with any nil field must return INVALID_PARAMS_ERROR (code %d)
+        """, *globals.INVALID_PARAMS_ERROR),
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Before Cancun, 0x00 ExcessBlobGas, Nil BlobGasUsed, Nil Versioned Hashes, Nil Beacon Root",
+      about: """
+      Test sending NewPayloadV3 Before Cancun with:
+      - 0x00 ExcessBlobGas
+      - nil BlobGasUsed
+      - nil Versioned Hashes Array
+      - nil Beacon Root
+      """,
+      mainFork:   Cancun,
+      forkHeight: 2,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        NewPayloadCustomizer: &helper.UpgradeNewPayloadVersion{
+          NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+            payloadCustomizer: CustomPayloadData(
+              ExcessBlobGas: pUint64(0),
+            ),
+            ExpectedError: globals.INVALID_PARAMS_ERROR,
+          ),
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        NewPayloadV3 before Cancun with any nil field must return INVALID_PARAMS_ERROR (code %d)
+        """, *globals.INVALID_PARAMS_ERROR),
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Before Cancun, Nil Data Fields, Empty Array Versioned Hashes, Nil Beacon Root",
+      about: """
+        Test sending NewPayloadV3 Before Cancun with:
+        - nil ExcessBlobGas
+        - nil BlobGasUsed
+        - Empty Versioned Hashes Array
+        - nil Beacon Root
+      """,
+      mainFork:   Cancun,
+      forkHeight: 2,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        NewPayloadCustomizer: &helper.UpgradeNewPayloadVersion{
+          NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+            payloadCustomizer: CustomPayloadData(
+              VersionedHashesCustomizer: &VersionedHashes{
+                Blobs: []helper.BlobID{),
+              ),
+            ),
+            ExpectedError: globals.INVALID_PARAMS_ERROR,
+          ),
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        NewPayloadV3 before Cancun with any nil field must return INVALID_PARAMS_ERROR (code %d)
+        """, *globals.INVALID_PARAMS_ERROR),
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Before Cancun, Nil Data Fields, Nil Versioned Hashes, Zero Beacon Root",
+      about: """
+      Test sending NewPayloadV3 Before Cancun with:
+      - nil ExcessBlobGas
+      - nil BlobGasUsed
+      - nil Versioned Hashes Array
+      - Zero Beacon Root
+      """,
+      mainFork:   Cancun,
+      forkHeight: 2,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        NewPayloadCustomizer: &helper.UpgradeNewPayloadVersion{
+          NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+            payloadCustomizer: CustomPayloadData(
+              ParentBeaconRoot: &(common.Hash{}),
+            ),
+            ExpectedError: globals.INVALID_PARAMS_ERROR,
+          ),
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        NewPayloadV3 before Cancun with any nil field must return INVALID_PARAMS_ERROR (code %d)
+        """, *globals.INVALID_PARAMS_ERROR),
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Before Cancun, 0x00 Data Fields, Empty Array Versioned Hashes, Zero Beacon Root",
+      about: """
+      Test sending NewPayloadV3 Before Cancun with:
+      - 0x00 ExcessBlobGas
+      - 0x00 BlobGasUsed
+      - Empty Versioned Hashes Array
+      - Zero Beacon Root
+      """,
+      mainFork:   Cancun,
+      forkHeight: 2,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        NewPayloadCustomizer: &helper.UpgradeNewPayloadVersion{
+          NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+            payloadCustomizer: CustomPayloadData(
+              ExcessBlobGas:    pUint64(0),
+              BlobGasUsed:      pUint64(0),
+              ParentBeaconRoot: &(common.Hash{}),
+              VersionedHashesCustomizer: &VersionedHashes{
+                Blobs: []helper.BlobID{),
+              ),
+            ),
+            ExpectedError: globals.UNSUPPORTED_FORK_ERROR,
+          ),
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        NewPayloadV3 before Cancun with no nil fields must return UNSUPPORTED_FORK_ERROR (code %d)
+        """, *globals.UNSUPPORTED_FORK_ERROR),
+      ),
+    ),
+  ),
+
+  # NewPayloadV3 After Cancun, Negative Tests
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 After Cancun, Nil ExcessBlobGas, 0x00 BlobGasUsed, Empty Array Versioned Hashes, Zero Beacon Root",
+      about: """
+      Test sending NewPayloadV3 After Cancun with:
+      - nil ExcessBlobGas
+      - 0x00 BlobGasUsed
+      - Empty Versioned Hashes Array
+      - Zero Beacon Root
+      """,
+      mainFork:   Cancun,
+      forkHeight: 1,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            RemoveExcessBlobGas: true,
+          ),
+          ExpectedError: globals.INVALID_PARAMS_ERROR,
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        NewPayloadV3 after Cancun with nil ExcessBlobGas must return INVALID_PARAMS_ERROR (code %d)
+        """, *globals.INVALID_PARAMS_ERROR),
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 After Cancun, 0x00 ExcessBlobGas, Nil BlobGasUsed, Empty Array Versioned Hashes",
+      about: """
+      Test sending NewPayloadV3 After Cancun with:
+      - 0x00 ExcessBlobGas
+      - nil BlobGasUsed
+      - Empty Versioned Hashes Array
+      """,
+      mainFork:   Cancun,
+      forkHeight: 1,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            RemoveBlobGasUsed: true,
+          ),
+          ExpectedError: globals.INVALID_PARAMS_ERROR,
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        NewPayloadV3 after Cancun with nil BlobGasUsed must return INVALID_PARAMS_ERROR (code %d)
+        """, *globals.INVALID_PARAMS_ERROR),
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 After Cancun, 0x00 Blob Fields, Empty Array Versioned Hashes, Nil Beacon Root",
+      about: """
+      Test sending NewPayloadV3 After Cancun with:
+      - 0x00 ExcessBlobGas
+      - nil BlobGasUsed
+      - Empty Versioned Hashes Array
+      """,
+      mainFork:   Cancun,
+      forkHeight: 1,
+    ),
+
+    testSequence: @[
+      NewPayloads(
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            RemoveParentBeaconRoot: true,
+          ),
+          ExpectedError: globals.INVALID_PARAMS_ERROR,
+        ),
+        ExpectationDescription: fmt.Sprintf("""
+        NewPayloadV3 after Cancun with nil parentBeaconBlockRoot must return INVALID_PARAMS_ERROR (code %d)
+        """, *globals.INVALID_PARAMS_ERROR),
+      ),
+    ),
+  ),
+
+  # Fork time tests
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "ForkchoiceUpdatedV2 then ForkchoiceUpdatedV3 Valid Payload Building Requests",
+      about: """
+      Test requesting a Shanghai ForkchoiceUpdatedV2 payload followed by a Cancun ForkchoiceUpdatedV3 request.
+      Verify that client correctly returns the Cancun payload.
+      """,
+      mainFork: Cancun,
+      # We request two blocks from the client, first on shanghai and then on cancun, both with
+      # the same parent.
+      # Client must respond correctly to later request.
+      forkHeight:              1,
+      BlockTimestampIncrement: 2,
+    ),
+
+    testSequence: @[
+      # First, we send a couple of blob transactions on genesis,
+      # with enough data gas cost to make sure they are included in the first block.
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        # This customizer only simulates requesting a Shanghai payload 1 second before cancun.
+        # CL Mock will still request the Cancun payload afterwards
+        FcUOnPayloadRequest: &helper.BaseForkchoiceUpdatedCustomizer{
+          PayloadAttributesCustomizer: &helper.TimestampDeltaPayloadAttributesCustomizer{
+            PayloadAttributesCustomizer: &helper.BasePayloadAttributesCustomizer{
+              RemoveBeaconRoot: true,
+            ),
+            TimestampDelta: -1,
+          ),
+        ),
+        ExpectationDescription: """
+        ForkchoiceUpdatedV3 must construct transaction with blob payloads even if a ForkchoiceUpdatedV2 was previously requested
+        """,
+      ),
+    ),
+  ),
+
+  # Test versioned hashes in Engine API NewPayloadV3
+  TestDesc(
+    spec: CancunSpec(
+
+
+      name: "NewPayloadV3 Versioned Hashes, Missing Hash",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      is missing one of the hashes.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: getBlobList(0, TARGET_BLOBS_PER_BLOCK-1),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+        ExpectationDescription: """
+        NewPayloadV3 with incorrect list of versioned hashes must return INVALID status
+        """,
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+
+      name: "NewPayloadV3 Versioned Hashes, Extra Hash",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      is has an extra hash for a blob that is not in the payload.
+      """,
+      mainFork: Cancun,
+    ),
+    # TODO: It could be worth it to also test this with a blob that is in the
+    # mempool but was not included in the payload.
+    testSequence: @[
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: getBlobList(0, TARGET_BLOBS_PER_BLOCK+1),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+        ExpectationDescription: """
+        NewPayloadV3 with incorrect list of versioned hashes must return INVALID status
+        """,
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Out of Order",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      is out of order.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: getBlobListByIndex(helper.BlobID(TARGET_BLOBS_PER_BLOCK-1), 0),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+        ExpectationDescription: """
+        NewPayloadV3 with incorrect list of versioned hashes must return INVALID status
+        """,
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Repeated Hash",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      has a blob that is repeated in the array.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: append(getBlobList(0, TARGET_BLOBS_PER_BLOCK), helper.BlobID(TARGET_BLOBS_PER_BLOCK-1)),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+        ExpectationDescription: """
+        NewPayloadV3 with incorrect list of versioned hashes must return INVALID status
+        """,
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Incorrect Hash",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      has a blob hash that does not belong to any blob contained in the payload.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: append(getBlobList(0, TARGET_BLOBS_PER_BLOCK-1), helper.BlobID(TARGET_BLOBS_PER_BLOCK)),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+        ExpectationDescription: """
+        NewPayloadV3 with incorrect hash in list of versioned hashes must return INVALID status
+        """,
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Incorrect Version",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      has a single blob that has an incorrect version.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs:        getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+              HashVersions: []byte{VERSIONED_HASH_VERSION_KZG, VERSIONED_HASH_VERSION_KZG + 1),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+        ExpectationDescription: """
+        NewPayloadV3 with incorrect version in list of versioned hashes must return INVALID status
+        """,
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Nil Hashes",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      is nil, even though the fork has already happened.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: nil,
+            ),
+          ),
+          ExpectedError: globals.INVALID_PARAMS_ERROR,
+        ),
+        ExpectationDescription: """
+        NewPayloadV3 after Cancun with nil VersionedHashes must return INVALID_PARAMS_ERROR (code -32602)
+        """,
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Empty Hashes",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      is empty, even though there are blobs in the payload.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: []helper.BlobID{),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+        ExpectationDescription: """
+        NewPayloadV3 with incorrect list of versioned hashes must return INVALID status
+        """,
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Non-Empty Hashes",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      is contains hashes, even though there are no blobs in the payload.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      NewPayloads(
+        expectedBlobs: []helper.BlobID{),
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: []helper.BlobID{0),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+        ExpectationDescription: """
+        NewPayloadV3 with incorrect list of versioned hashes must return INVALID status
+        """,
+      ),
+    ),
+  ),
+
+  # Test versioned hashes in Engine API NewPayloadV3 on syncing clients
+  TestDesc(
+    spec: CancunSpec(
+
+
+      name: "NewPayloadV3 Versioned Hashes, Missing Hash (Syncing)",
+      about: """
+        Tests VersionedHashes in Engine API NewPayloadV3 where the array
+        is missing one of the hashes.
+        """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      NewPayloads(), # Send new payload so the parent is unknown to the secondary client
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+      ),
+
+      LaunchClients{
+        EngineStarter:            hive_rpc.HiveRPCEngineStarter{),
+        SkipAddingToCLMock:       true,
+        SkipConnectingToBootnode: true, # So the client is in a perpetual syncing state
+      ),
+      SendModifiedLatestPayload{
+        ClientID: 1,
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: getBlobList(0, TARGET_BLOBS_PER_BLOCK-1),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+
+      name: "NewPayloadV3 Versioned Hashes, Extra Hash (Syncing)",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      is has an extra hash for a blob that is not in the payload.
+      """,
+      mainFork: Cancun,
+    ),
+    # TODO: It could be worth it to also test this with a blob that is in the
+    # mempool but was not included in the payload.
+    testSequence: @[
+      NewPayloads(), # Send new payload so the parent is unknown to the secondary client
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+      ),
+
+      LaunchClients{
+        EngineStarter:            hive_rpc.HiveRPCEngineStarter{),
+        SkipAddingToCLMock:       true,
+        SkipConnectingToBootnode: true, # So the client is in a perpetual syncing state
+      ),
+      SendModifiedLatestPayload{
+        ClientID: 1,
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: getBlobList(0, TARGET_BLOBS_PER_BLOCK+1),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Out of Order (Syncing)",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      is out of order.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      NewPayloads(), # Send new payload so the parent is unknown to the secondary client
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+      ),
+      LaunchClients{
+        EngineStarter:            hive_rpc.HiveRPCEngineStarter{),
+        SkipAddingToCLMock:       true,
+        SkipConnectingToBootnode: true, # So the client is in a perpetual syncing state
+      ),
+      SendModifiedLatestPayload{
+        ClientID: 1,
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: getBlobListByIndex(helper.BlobID(TARGET_BLOBS_PER_BLOCK-1), 0),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Repeated Hash (Syncing)",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      has a blob that is repeated in the array.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      NewPayloads(), # Send new payload so the parent is unknown to the secondary client
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+      ),
+
+      LaunchClients{
+        EngineStarter:            hive_rpc.HiveRPCEngineStarter{),
+        SkipAddingToCLMock:       true,
+        SkipConnectingToBootnode: true, # So the client is in a perpetual syncing state
+      ),
+      SendModifiedLatestPayload{
+        ClientID: 1,
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: append(getBlobList(0, TARGET_BLOBS_PER_BLOCK), helper.BlobID(TARGET_BLOBS_PER_BLOCK-1)),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Incorrect Hash (Syncing)",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      has a blob that is repeated in the array.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      NewPayloads(), # Send new payload so the parent is unknown to the secondary client
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+      ),
+
+      LaunchClients{
+        EngineStarter:            hive_rpc.HiveRPCEngineStarter{),
+        SkipAddingToCLMock:       true,
+        SkipConnectingToBootnode: true, # So the client is in a perpetual syncing state
+      ),
+      SendModifiedLatestPayload{
+        ClientID: 1,
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: append(getBlobList(0, TARGET_BLOBS_PER_BLOCK-1), helper.BlobID(TARGET_BLOBS_PER_BLOCK)),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Incorrect Version (Syncing)",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      has a single blob that has an incorrect version.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      NewPayloads(), # Send new payload so the parent is unknown to the secondary client
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+      ),
+
+      LaunchClients{
+        EngineStarter:            hive_rpc.HiveRPCEngineStarter{),
+        SkipAddingToCLMock:       true,
+        SkipConnectingToBootnode: true, # So the client is in a perpetual syncing state
+      ),
+      SendModifiedLatestPayload{
+        ClientID: 1,
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs:        getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+              HashVersions: []byte{VERSIONED_HASH_VERSION_KZG, VERSIONED_HASH_VERSION_KZG + 1),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Nil Hashes (Syncing)",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      is nil, even though the fork has already happened.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      NewPayloads(), # Send new payload so the parent is unknown to the secondary client
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+      ),
+
+      LaunchClients{
+        EngineStarter:            hive_rpc.HiveRPCEngineStarter{),
+        SkipAddingToCLMock:       true,
+        SkipConnectingToBootnode: true, # So the client is in a perpetual syncing state
+      ),
+      SendModifiedLatestPayload{
+        ClientID: 1,
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: nil,
+            ),
+          ),
+          ExpectedError: globals.INVALID_PARAMS_ERROR,
+        ),
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Empty Hashes (Syncing)",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      is empty, even though there are blobs in the payload.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      NewPayloads(), # Send new payload so the parent is unknown to the secondary client
+      SendBlobTransactions(
+        transactionCount:              TARGET_BLOBS_PER_BLOCK,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      NewPayloads(
+        expectedIncludedBlobCount: TARGET_BLOBS_PER_BLOCK,
+        expectedBlobs:             getBlobList(0, TARGET_BLOBS_PER_BLOCK),
+      ),
+
+      LaunchClients{
+        EngineStarter:            hive_rpc.HiveRPCEngineStarter{),
+        SkipAddingToCLMock:       true,
+        SkipConnectingToBootnode: true, # So the client is in a perpetual syncing state
+      ),
+      SendModifiedLatestPayload{
+        ClientID: 1,
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: []helper.BlobID{),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+      ),
+    ),
+  ),
+
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "NewPayloadV3 Versioned Hashes, Non-Empty Hashes (Syncing)",
+      about: """
+      Tests VersionedHashes in Engine API NewPayloadV3 where the array
+      is contains hashes, even though there are no blobs in the payload.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      NewPayloads(), # Send new payload so the parent is unknown to the secondary client
+      NewPayloads(
+        expectedBlobs: []helper.BlobID{),
+      ),
+
+      LaunchClients{
+        EngineStarter:            hive_rpc.HiveRPCEngineStarter{),
+        SkipAddingToCLMock:       true,
+        SkipConnectingToBootnode: true, # So the client is in a perpetual syncing state
+      ),
+      SendModifiedLatestPayload{
+        ClientID: 1,
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            VersionedHashesCustomizer: &VersionedHashes{
+              Blobs: []helper.BlobID{0),
+            ),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+      ),
+    ),
+  ),
+
+  # BlobGasUsed, ExcessBlobGas Negative Tests
+  # Most cases are contained in https:#github.com/ethereum/execution-spec-tests/tree/main/tests/cancun/eip4844_blobs
+  # and can be executed using """pyspec""" simulator.
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "Incorrect BlobGasUsed: Non-Zero on Zero Blobs",
+      about: """
+      Send a payload with zero blobs, but non-zero BlobGasUsed.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      NewPayloads(
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            BlobGasUsed: pUint64(1),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+      ),
+    ),
+  ),
+  TestDesc(
+    spec: CancunSpec(
+
+
+      name: "Incorrect BlobGasUsed: GAS_PER_BLOB on Zero Blobs",
+      about: """
+      Send a payload with zero blobs, but non-zero BlobGasUsed.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      NewPayloads(
+        NewPayloadCustomizer: &helper.BaseNewPayloadVersionCustomizer{
+          payloadCustomizer: CustomPayloadData(
+            BlobGasUsed: pUint64(cancun.GAS_PER_BLOB),
+          ),
+          ExpectInvalidStatus: true,
+        ),
+      ),
+    ),
+  ),
+
+  # DevP2P tests
+  TestDesc(
+    spec: CancunSpec(
+
+      name: "Request Blob Pooled Transactions",
+      about: """
+      Requests blob pooled transactions and verify correct encoding.
+      """,
+      mainFork: Cancun,
+    ),
+    testSequence: @[
+      # Get past the genesis
+      NewPayloads(
+        payloadCount: 1,
+      ),
+      # Send multiple transactions with multiple blobs each
+      SendBlobTransactions(
+        transactionCount:              1,
+        blobTransactionMaxBlobGasCost: u256(1),
+      ),
+      DevP2PRequestPooledTransactionHash{
+        ClientIndex:                 0,
+        TransactionIndexes:          []uint64{0),
+        WaitForNewPooledTransaction: true,
+      ),
+    ),
+  ),
+}
+
+var EngineAPITests []test.Spec
+
+func init() {
+  # Append all engine api tests with Cancun as main fork
+  for _, test := range suite_engine.Tests {
+    Tests = append(Tests, test.WithMainFork(Cancun))
+  }
+
+  # Cancun specific variants for pre-existing tests
+  baseSpec := test.BaseSpec{
+    mainFork: Cancun,
+  }
+  onlyBlobTxsSpec := test.BaseSpec{
+    mainFork:            Cancun,
+    TestTransactionType: helper.BlobTxOnly,
+  }
+
+  # Payload Attributes
+  for _, t := range []suite_engine.InvalidPayloadAttributesTest{
+    {
+      BaseSpec:    baseSpec,
+      Description: "Missing BeaconRoot",
+      Customizer: &helper.BasePayloadAttributesCustomizer{
+        RemoveBeaconRoot: true,
+      ),
+      # Error is expected on syncing because V3 checks all fields to be present
+      ErrorOnSync: true,
+    ),
+  } {
+    Tests = append(Tests, t)
+    t.Syncing = true
+    Tests = append(Tests, t)
+  }
+
+  # Unique Payload ID Tests
+  for _, t := range []suite_engine.PayloadAttributesFieldChange{
+    suite_engine.PayloadAttributesParentBeaconRoot,
+    # TODO: Remove when withdrawals suite is refactored
+    suite_engine.PayloadAttributesAddWithdrawal,
+    suite_engine.PayloadAttributesModifyWithdrawalAmount,
+    suite_engine.PayloadAttributesModifyWithdrawalIndex,
+    suite_engine.PayloadAttributesModifyWithdrawalValidator,
+    suite_engine.PayloadAttributesModifyWithdrawalAddress,
+    suite_engine.PayloadAttributesRemoveWithdrawal,
+  } {
+    Tests = append(Tests, suite_engine.UniquePayloadIDTest{
+      BaseSpec:          baseSpec,
+      FieldModification: t,
+    })
+  }
+
+  # Invalid Payload Tests
+  for _, invalidField := range []helper.InvalidPayloadBlockField{
+    helper.InvalidParentBeaconBlockRoot,
+    helper.InvalidBlobGasUsed,
+    helper.InvalidBlobCountGasUsed,
+    helper.InvalidExcessBlobGas,
+    helper.InvalidVersionedHashes,
+    helper.InvalidVersionedHashesVersion,
+    helper.IncompleteVersionedHashes,
+    helper.ExtraVersionedHashes,
+  } {
+    for _, syncing := range []bool{false, true} {
+      # Invalidity of payload can be detected even when syncing because the
+      # blob gas only depends on the transactions contained.
+      invalidDetectedOnSync := (invalidField == helper.InvalidBlobGasUsed ||
+        invalidField == helper.InvalidBlobCountGasUsed ||
+        invalidField == helper.InvalidVersionedHashes ||
+        invalidField == helper.InvalidVersionedHashesVersion ||
+        invalidField == helper.IncompleteVersionedHashes ||
+        invalidField == helper.ExtraVersionedHashes)
+
+      nilLatestValidHash := (invalidField == helper.InvalidVersionedHashes ||
+        invalidField == helper.InvalidVersionedHashesVersion ||
+        invalidField == helper.IncompleteVersionedHashes ||
+        invalidField == helper.ExtraVersionedHashes)
+
+      Tests = append(Tests, suite_engine.InvalidPayloadTestCase{
+        BaseSpec:              onlyBlobTxsSpec,
+        InvalidField:          invalidField,
+        Syncing:               syncing,
+        InvalidDetectedOnSync: invalidDetectedOnSync,
+        NilLatestValidHash:    nilLatestValidHash,
+      })
+    }
+  }
+
+  # Invalid Transaction ChainID Tests
+  Tests = append(Tests,
+    suite_engine.InvalidTxChainIDTest{
+      BaseSpec: onlyBlobTxsSpec,
+    ),
+  )
+
+  Tests = append(Tests, suite_engine.PayloadBuildAfterInvalidPayloadTest{
+    BaseSpec:     onlyBlobTxsSpec,
+    InvalidField: helper.InvalidParentBeaconBlockRoot,
+  })
+
+  # Suggested Fee Recipient Tests (New Transaction Type)
+  Tests = append(Tests,
+    suite_engine.SuggestedFeeRecipientTest{
+      BaseSpec:         onlyBlobTxsSpec,
+      transactionCount: 1, # Only one blob tx gets through due to blob gas limit
+    ),
+  )
+  # Prev Randao Tests (New Transaction Type)
+  Tests = append(Tests,
+    suite_engine.PrevRandaoTransactionTest{
+      BaseSpec: onlyBlobTxsSpec,
+    ),
+  )
+}
+]#
\ No newline at end of file
diff --git a/hive_integration/nodocker/engine/clmock.nim b/hive_integration/nodocker/engine/clmock.nim
index 39dd54aec..81a845387 100644
--- a/hive_integration/nodocker/engine/clmock.nim
+++ b/hive_integration/nodocker/engine/clmock.nim
@@ -2,7 +2,7 @@ import
   std/[tables],
   chronicles,
   nimcrypto/sysrand,
-  stew/[byteutils, endians2],
+  stew/[byteutils],
   eth/common, chronos,
   json_rpc/rpcclient,
   ../../../nimbus/beacon/execution_types,
@@ -12,7 +12,8 @@ import
   ../../../nimbus/common as nimbus_common,
   ./client_pool,
   ./engine_env,
-  ./engine_client
+  ./engine_client,
+  ./types
 
 import web3/engine_api_types except Hash256  # conflict with the one from eth/common
 
@@ -24,9 +25,10 @@ type
     # Number of required slots before a block which was set as Head moves to `safe` and `finalized` respectively
     slotsToSafe*     : int
     slotsToFinalized*: int
+    safeSlotsToImportOptimistically*: int
 
     # Wait time before attempting to get the payload
-    payloadProductionClientDelay: int
+    payloadProductionClientDelay*: int
 
     # Block production related
     blockTimestampIncrement*: Option[int]
@@ -52,6 +54,7 @@ type
     latestPayloadBuilt*     : ExecutionPayload
     latestBlockValue*       : Option[UInt256]
     latestBlobsBundle*      : Option[BlobsBundleV1]
+    latestShouldOverrideBuilder*: Option[bool]
     latestPayloadAttributes*: PayloadAttributes
     latestExecutedPayload*  : ExecutionPayload
     latestForkchoice*       : ForkchoiceStateV1
@@ -60,7 +63,6 @@ type
     firstPoSBlockNumber       : Option[uint64]
     ttdReached*               : bool
     transitionPayloadTimestamp: Option[int]
-    safeSlotsToImportOptimistically: int
     chainTotalDifficulty      : UInt256
 
     # Shanghai related
@@ -68,6 +70,7 @@ type
 
   BlockProcessCallbacks* = object
     onPayloadProducerSelected* : proc(): bool {.gcsafe.}
+    onPayloadAttributesGenerated* : proc(): bool {.gcsafe.}
     onRequestNextPayload*      : proc(): bool {.gcsafe.}
     onGetPayload*              : proc(): bool {.gcsafe.}
     onNewPayloadBroadcast*     : proc(): bool {.gcsafe.}
@@ -100,7 +103,7 @@ proc init(cl: CLMocker, eng: EngineEnv, com: CommonRef) =
   cl.com = com
   cl.slotsToSafe = 1
   cl.slotsToFinalized = 2
-  cl.payloadProductionClientDelay = 1
+  cl.payloadProductionClientDelay = 0
   cl.headerHistory[0] = com.genesisHeader()
 
 proc newClMocker*(eng: EngineEnv, com: CommonRef): CLMocker =
@@ -179,11 +182,6 @@ func getNextBlockTimestamp(cl: CLMocker): EthTime =
 func setNextWithdrawals(cl: CLMocker, nextWithdrawals: Option[seq[WithdrawalV1]]) =
   cl.nextWithdrawals = nextWithdrawals
 
-func timestampToBeaconRoot(timestamp: Quantity): FixedBytes[32] =
-  # Generates a deterministic hash from the timestamp
-  let h = keccakHash(timestamp.uint64.toBytesBE)
-  FixedBytes[32](h.data)
-
 func isShanghai(cl: CLMocker, timestamp: Quantity): bool =
   let ts = EthTime(timestamp.uint64)
   cl.com.isShanghaiOrLater(ts)
@@ -222,7 +220,7 @@ proc pickNextPayloadProducer(cl: CLMocker): bool =
   doAssert cl.nextBlockProducer != nil
   return true
 
-proc requestNextPayload(cl: CLMocker): bool =
+proc generatePayloadAttributes(cl: CLMocker) =
   # Generate a random value for the PrevRandao field
   var nextPrevRandao: common.Hash256
   doAssert randomBytes(nextPrevRandao.data) == 32
@@ -246,6 +244,7 @@ proc requestNextPayload(cl: CLMocker): bool =
   let number = cl.latestHeader.blockNumber.truncate(uint64) + 1
   cl.prevRandaoHistory[number] = nextPrevRandao
 
+proc requestNextPayload(cl: CLMocker): bool =
   let version = cl.latestPayloadAttributes.version
   let client = cl.nextBlockProducer.client
   let res = client.forkchoiceUpdated(version, cl.latestForkchoice, some(cl.latestPayloadAttributes))
@@ -290,6 +289,7 @@ proc getNextPayload(cl: CLMocker): bool =
   cl.latestPayloadBuilt = x.executionPayload
   cl.latestBlockValue = x.blockValue
   cl.latestBlobsBundle = x.blobsBundle
+  cl.latestShouldOverrideBuilder = x.shouldOverrideBuilder
 
   let beaconRoot = ethHash cl.latestPayloadAttributes.parentBeaconblockRoot
   let header = blockHeader(cl.latestPayloadBuilt, beaconRoot)
@@ -333,7 +333,7 @@ proc getNextPayload(cl: CLMocker): bool =
   return true
 
 func versionedHashes(bb: BlobsBundleV1): seq[Web3Hash] =
-  doAssert(bb.commitments.len > 0)
+  #doAssert(bb.commitments.len > 0)
   result = newSeqOfCap[BlockHash](bb.commitments.len)
 
   for com in bb.commitments:
@@ -481,6 +481,12 @@ proc produceSingleBlock*(cl: CLMocker, cb: BlockProcessCallbacks): bool {.gcsafe
     if not cb.onPayloadProducerSelected():
       return false
 
+  cl.generatePayloadAttributes()
+
+  if cb.onPayloadAttributesGenerated != nil:
+    if not cb.onPayloadAttributesGenerated():
+      return false
+
   if not cl.requestNextPayload():
     return false
 
@@ -491,7 +497,9 @@ proc produceSingleBlock*(cl: CLMocker, cb: BlockProcessCallbacks): bool {.gcsafe
       return false
 
   # Give the client a delay between getting the payload ID and actually retrieving the payload
-  #time.Sleep(PayloadProductionClientDelay)
+  if cl.payloadProductionClientDelay != 0:
+    let period = chronos.seconds(cl.payloadProductionClientDelay)
+    waitFor sleepAsync(period)
 
   if not cl.getNextPayload():
     return false
diff --git a/hive_integration/nodocker/engine/engine/engine_spec.nim b/hive_integration/nodocker/engine/engine/engine_spec.nim
index 1d113a37c..c3cea99eb 100644
--- a/hive_integration/nodocker/engine/engine/engine_spec.nim
+++ b/hive_integration/nodocker/engine/engine/engine_spec.nim
@@ -16,8 +16,6 @@ type
     exec*: proc(env: TestEnv): bool
     ttd*: int64
     chainFile*: string
-    slotsToFinalized*: int
-    slotsToSafe*: int
 
 template testNP(res, cond: untyped, validHash = none(common.Hash256)) =
   testCond res.isOk
diff --git a/hive_integration/nodocker/engine/engine_client.nim b/hive_integration/nodocker/engine/engine_client.nim
index 042ee3de3..02bb6e7be 100644
--- a/hive_integration/nodocker/engine/engine_client.nim
+++ b/hive_integration/nodocker/engine/engine_client.nim
@@ -81,7 +81,8 @@ proc getPayload*(client: RpcClient,
     ok(GetPayloadResponse(
       executionPayload: executionPayload(x.executionPayload),
       blockValue: some(x.blockValue),
-      blobsBundle: some(x.blobsBundle)
+      blobsBundle: some(x.blobsBundle),
+      shouldOverrideBuilder: some(x.shouldOverrideBuilder),
     ))
   elif version == Version.V2:
     let x = client.getPayloadV2(payloadId).valueOr:
@@ -231,6 +232,7 @@ proc toBlockHeader(bc: eth_api.BlockObject): common.BlockHeader =
     withdrawalsRoot: bc.withdrawalsRoot,
     blobGasUsed    : maybeU64(bc.blobGasUsed),
     excessBlobGas  : maybeU64(bc.excessBlobGas),
+    parentBeaconBlockRoot: bc.parentBeaconBlockRoot,
   )
 
 proc toTransactions(txs: openArray[JsonNode]): seq[Transaction] =
@@ -293,7 +295,7 @@ type
     s*: UInt256
     chainId*: Option[ChainId]
     accessList*: Option[seq[rpc_types.AccessTuple]]
-    maxFeePerBlobGas*: Option[GasInt]
+    maxFeePerBlobGas*: Option[UInt256]
     versionedHashes*: Option[VersionedHashes]
 
 proc toRPCReceipt(rec: eth_api.ReceiptObject): RPCReceipt =
@@ -336,7 +338,7 @@ proc toRPCTx(tx: eth_api.TransactionObject): RPCTx =
     s: UInt256.fromHex(string tx.s),
     chainId: maybeChainId(tx.chainId),
     accessList: tx.accessList,
-    maxFeePerBlobGas: maybeInt64(tx.maxFeePerBlobGas),
+    maxFeePerBlobGas: maybeU256(tx.maxFeePerBlobGas),
     versionedHashes: tx.versionedHashes,
   )
 
diff --git a/hive_integration/nodocker/engine/engine_sim.nim b/hive_integration/nodocker/engine/engine_sim.nim
index 000ee0199..16ec93596 100644
--- a/hive_integration/nodocker/engine/engine_sim.nim
+++ b/hive_integration/nodocker/engine/engine_sim.nim
@@ -1,19 +1,24 @@
 import
   std/times,
+  chronicles,
+  stew/results,
   ./types,
-  ../sim_utils
+  ../sim_utils,
+  ../../../nimbus/core/eip4844
 
 import
   ./engine_tests,
   ./auths_tests,
   ./exchange_cap_tests,
-  ./withdrawal_tests
+  ./withdrawal_tests,
+  ./cancun_tests
 
 proc combineTests(): seq[TestDesc] =
   result.add wdTestList
   result.add ecTestList
   result.add authTestList
   result.add engineTestList
+  result.add cancunTestList
 
 let
   testList = combineTests()
@@ -22,6 +27,11 @@ proc main() =
   var stat: SimStat
   let start = getTime()
 
+  let res = loadKzgTrustedSetup()
+  if res.isErr:
+    fatal "Cannot load baked in Kzg trusted setup", msg=res.error
+    quit(QuitFailure)
+
   for x in testList:
     let status = if x.run(x.spec):
                    TestStatus.OK
diff --git a/hive_integration/nodocker/engine/engine_tests.nim b/hive_integration/nodocker/engine/engine_tests.nim
index de9d3d35e..0b4acefbd 100644
--- a/hive_integration/nodocker/engine/engine_tests.nim
+++ b/hive_integration/nodocker/engine/engine_tests.nim
@@ -1,7 +1,8 @@
 import
   ./engine/engine_spec,
   ./types,
-  ./test_env
+  ./test_env,
+  ./base_spec
 
 proc specExecute(ws: BaseSpec): bool =
   var
@@ -10,12 +11,7 @@ proc specExecute(ws: BaseSpec): bool =
 
   env.engine.setRealTTD(ws.ttd)
   env.setupCLMock()
-  
-  if ws.slotsToFinalized != 0:
-    env.slotsToFinalized(ws.slotsToFinalized)
-  if ws.slotsToSafe != 0:
-    env.slotsToSafe(ws.slotsToSafe)
-
+  ws.configureCLMock(env.clMock)
   result = ws.exec(env)
   env.close()
 
diff --git a/hive_integration/nodocker/engine/test_env.nim b/hive_integration/nodocker/engine/test_env.nim
index a83e59c4c..e5d1f3310 100644
--- a/hive_integration/nodocker/engine/test_env.nim
+++ b/hive_integration/nodocker/engine/test_env.nim
@@ -1,6 +1,7 @@
 import
   chronicles,
   eth/keys,
+  stew/results,
   json_rpc/rpcclient,
   ../../../nimbus/config,
   ../../../nimbus/common,
@@ -90,6 +91,15 @@ proc addEngine*(env: TestEnv, addToCL: bool = true): EngineEnv =
     env.clMock.addEngine(eng)
   eng
 
+func engines*(env: TestEnv, idx: int): EngineEnv =
+  env.clients[idx]
+
+func numEngines*(env: TestEnv): int =
+  env.clients.len
+
+func accounts*(env: TestEnv, idx: int): TestAccount =
+  env.sender.getAccount(idx)
+
 proc makeTx*(env: TestEnv, tc: BaseTx, nonce: AccountNonce): Transaction =
   env.sender.makeTx(tc, nonce)
 
@@ -132,6 +142,12 @@ proc sendTx*(env: TestEnv, tx: Transaction): bool =
   let client = env.engine.client
   sendTx(client, tx)
 
+proc sendTx*(env: TestEnv, sender: TestAccount, eng: EngineEnv, tc: BlobTx): Result[Transaction, void] =
+  env.sender.sendTx(sender, eng.client, tc)
+  
+proc replaceTx*(env: TestEnv, sender: TestAccount, eng: EngineEnv, tc: BlobTx): Result[Transaction, void] =
+  env.sender.replaceTx(sender, eng.client, tc)
+  
 proc verifyPoWProgress*(env: TestEnv, lastBlockHash: common.Hash256): bool =
   let res = waitFor env.client.verifyPoWProgress(lastBlockHash)
   if res.isErr:
@@ -139,9 +155,3 @@ proc verifyPoWProgress*(env: TestEnv, lastBlockHash: common.Hash256): bool =
     return false
 
   true
-
-proc slotsToSafe*(env: TestEnv, x: int) =
-  env.clMock.slotsToSafe = x
-
-proc slotsToFinalized*(env: TestEnv, x: int) =
-  env.clMock.slotsToFinalized = x
diff --git a/hive_integration/nodocker/engine/tx_sender.nim b/hive_integration/nodocker/engine/tx_sender.nim
index 844833803..b29e889d8 100644
--- a/hive_integration/nodocker/engine/tx_sender.nim
+++ b/hive_integration/nodocker/engine/tx_sender.nim
@@ -5,6 +5,7 @@ import
   nimcrypto/sha2,
   chronicles,
   ./engine_client,
+  ./cancun/blobs,
   ../../../nimbus/transaction,
   ../../../nimbus/common,
   ../../../nimbus/utils/utils
@@ -22,7 +23,15 @@ type
     padByte*       : uint8
     initcode*      : seq[byte]
 
-  TestAccount = object
+  # Blob transaction creator
+  BlobTx* = object of BaseTx
+    gasFee*    : GasInt
+    gasTip*    : GasInt
+    blobGasFee*: UInt256
+    blobID*    : BlobID
+    blobCount* : int
+
+  TestAccount* = object
     key    : PrivateKey
     address: EthAddress
     index  : int
@@ -38,8 +47,21 @@ type
     key*    : PrivateKey
     nonce*  : AccountNonce
 
+  CustomTransactionData* = object
+    nonce*              : Option[uint64]
+    gasPriceOrGasFeeCap*: Option[GasInt]
+    gasTipCap*          : Option[GasInt]
+    gas*                : Option[GasInt]
+    to*                 : Option[common.EthAddress]
+    value*              : Option[UInt256]
+    data*               : Option[seq[byte]]
+    chainId*            : Option[ChainId]
+    signature*          : Option[UInt256]
+
 const
   TestAccountCount = 1000
+  gasPrice* = 30.gwei
+  gasTipPrice* = 1.gwei
 
 func toAddress(key: PrivateKey): EthAddress =
   toKeyPair(key).pubkey.toCanonicalAddress()
@@ -67,6 +89,9 @@ proc getNextNonce(sender: TxSender, address: EthAddress): uint64 =
   sender.nonceMap[address] = nonce + 1
   nonce
 
+proc getLastNonce(sender: TxSender, address: EthAddress): uint64 =
+  sender.nonceMap.getOrDefault(address, 0'u64)
+
 proc fillBalance(sender: TxSender, params: NetworkParams) =
   for x in sender.accounts:
     params.genesis.alloc[x.address] = GenesisAccount(
@@ -89,9 +114,6 @@ proc getTxType(tc: BaseTx, nonce: uint64): TxType =
 
 proc makeTx(params: MakeTxParams, tc: BaseTx): Transaction =
   const
-    gasPrice = 30.gwei
-    gasTipPrice = 1.gwei
-
     gasFeeCap = gasPrice
     gasTipCap = gasTipPrice
 
@@ -212,3 +234,74 @@ proc sendTx*(client: RpcClient, tx: Transaction): bool =
     error "Unable to send transaction", msg=rr.error
     return false
   return true
+
+proc makeTx*(params: MakeTxParams, tc: BlobTx): Transaction =
+  # Need tx wrap data that will pass blob verification
+  let data = blobDataGenerator(tc.blobID, tc.blobCount)
+  doAssert(tc.recipient.isSome, "nil recipient address")
+
+  # Collect fields for transaction
+  let
+    gasFeeCap = if tc.gasFee != 0.GasInt: tc.gasFee
+                else: gasPrice
+    gasTipCap = if tc.gasTip != 0.GasInt: tc.gasTip
+                else: gasTipPrice
+
+  let unsignedTx = Transaction(
+    txType    : TxEIP4844,
+    chainId   : params.chainId,
+    nonce     : params.nonce,
+    maxPriorityFee: gasTipCap,
+    maxFee    : gasFeeCap,
+    gasLimit  : tc.gasLimit,
+    to        : tc.recipient,
+    value     : tc.amount,
+    payload   : tc.payload,
+    maxFeePerBlobGas: tc.blobGasFee,
+    versionedHashes: data.hashes,
+  )
+
+  var tx = signTransaction(unsignedTx, params.key, params.chainId, eip155 = true)
+  tx.networkPayload = NetworkPayload(
+    blobs      : data.blobs,
+    commitments: data.commitments,
+    proofs     : data.proofs,
+  )
+
+  tx
+
+proc getAccount*(sender: TxSender, idx: int): TestAccount =
+  sender.accounts[idx]
+
+proc sendTx*(sender: TxSender, acc: TestAccount, client: RpcClient, tc: BlobTx): Result[Transaction, void] =
+  let
+    params = MakeTxParams(
+      chainId: sender.chainId,
+      key: acc.key,
+      nonce: sender.getNextNonce(acc.address),
+    )
+    tx = params.makeTx(tc)
+
+  let rr = client.sendTransaction(tx)
+  if rr.isErr:
+    error "Unable to send transaction", msg=rr.error
+    return err()
+  return ok(tx)
+
+proc replaceTx*(sender: TxSender, acc: TestAccount, client: RpcClient, tc: BlobTx): Result[Transaction, void] =
+  let
+    params = MakeTxParams(
+      chainId: sender.chainId,
+      key: acc.key,
+      nonce: sender.getLastNonce(acc.address),
+    )
+    tx = params.makeTx(tc)
+
+  let rr = client.sendTransaction(tx)
+  if rr.isErr:
+    error "Unable to send transaction", msg=rr.error
+    return err()
+  return ok(tx)
+
+proc customizeTransaction*(sender: TxSender, baseTx: Transaction, custTx: CustomTransactionData): Transaction =
+  discard
diff --git a/hive_integration/nodocker/engine/types.nim b/hive_integration/nodocker/engine/types.nim
index 6663c6618..329561fbb 100644
--- a/hive_integration/nodocker/engine/types.nim
+++ b/hive_integration/nodocker/engine/types.nim
@@ -1,7 +1,7 @@
 import
   std/[options, typetraits, strutils],
   eth/common,
-  stew/byteutils,
+  stew/[byteutils, endians2],
   web3/ethtypes,
   web3/engine_api_types,
   ../../../nimbus/beacon/execution_types,
@@ -11,6 +11,18 @@ type
   BaseSpec* = ref object of RootObj
     txType*: Option[TxType]
 
+    # CL Mocker configuration for slots to `safe` and `finalized` respectively
+    slotsToSafe*: int
+    slotsToFinalized*: int
+    safeSlotsToImportOptimistically*: int
+    blockTimestampIncrement*: int
+    timeoutSeconds*: int
+    mainFork*: string
+    genesisTimestamp*: int
+    forkHeight*: int
+    forkTime*: uint64
+    previousForkTime*: uint64
+
   TestDesc* = object
     name* : string
     about*: string
@@ -21,6 +33,29 @@ const
   DefaultTimeout* = 60 # seconds
   DefaultSleep* = 1
   prevRandaoContractAddr* = hexToByteArray[20]("0000000000000000000000000000000000000316")
+  GenesisTimestamp* = 0x1234
+  ForkParis*    = "Paris"
+  ForkShanghai* = "Shanghai"
+  ForkCancun*   = "Cancun"
+
+func toAddress*(x: UInt256): EthAddress =
+  var
+    mm = x.toByteArrayBE
+    x = 0
+  for i in 12..31:
+    result[x] = mm[i]
+    inc x
+
+func toHash*(x: UInt256): common.Hash256 =
+  common.Hash256(data: x.toByteArrayBE)
+
+func timestampToBeaconRoot*(timestamp: Quantity): FixedBytes[32] =
+  # Generates a deterministic hash from the timestamp
+  let h = keccakHash(timestamp.uint64.toBytesBE)
+  FixedBytes[32](h.data)
+
+func beaconRoot*(x: UInt256): FixedBytes[32] =
+  FixedBytes[32](x.toByteArrayBE)
 
 template testCond*(expr: untyped) =
   if not (expr):
diff --git a/hive_integration/nodocker/engine/withdrawal_tests.nim b/hive_integration/nodocker/engine/withdrawal_tests.nim
index 3b57b64db..0a134e50e 100644
--- a/hive_integration/nodocker/engine/withdrawal_tests.nim
+++ b/hive_integration/nodocker/engine/withdrawal_tests.nim
@@ -6,9 +6,11 @@ import
   withdrawals/wd_reorg_spec,
   withdrawals/wd_sync_spec,
   ./types,
-  ./test_env
+  ./test_env,
+  ./base_spec
 
 proc specExecute[T](ws: BaseSpec): bool =
+  ws.mainFork = ForkShanghai
   let
     ws   = T(ws)
     conf = envConfig(ws.getForkConfig())
@@ -29,10 +31,10 @@ let wdTestList* = [
     about: "Tests a 8 block re-org using NewPayload. Re-org does not change withdrawals fork height",
     run: specExecute[ReorgSpec],
     spec: ReorgSpec(
-      slotsToSafe:      u256(32),
-      slotsToFinalized: u256(64),
+      slotsToSafe:      32,
+      slotsToFinalized: 64,
       timeoutSeconds:   300,
-      wdForkHeight: 1, # Genesis is Pre-Withdrawals
+      forkHeight: 1, # Genesis is Pre-Withdrawals
       wdBlockCount: MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       wdPerBlock:   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       reOrgBlockCount: 8,
@@ -45,10 +47,10 @@ let wdTestList* = [
       #  the payload at the height of the fork
     run: specExecute[ReorgSpec],
     spec: ReorgSpec(
-      slotsToSafe:      u256(32),
-      slotsToFinalized: u256(64),
+      slotsToSafe:      32,
+      slotsToFinalized: 64,
       timeoutSeconds:   300,
-      wdForkHeight: 8, # Genesis is Pre-Withdrawals
+      forkHeight: 8, # Genesis is Pre-Withdrawals
       wdBlockCount: 8,
       wdPerBlock:   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       reOrgBlockCount: 10,
@@ -61,10 +63,10 @@ let wdTestList* = [
       # than the canonical chain
     run: specExecute[ReorgSpec],
     spec: ReorgSpec(
-      slotsToSafe:      u256(32),
-      slotsToFinalized: u256(64),
+      slotsToSafe:      32,
+      slotsToFinalized: 64,
       timeoutSeconds:   300,
-      wdForkHeight: 8, # Genesis is Pre-Withdrawals
+      forkHeight: 8, # Genesis is Pre-Withdrawals
       wdBlockCount: 8,
       wdPerBlock:   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       reOrgBlockCount:         10,
@@ -78,13 +80,13 @@ let wdTestList* = [
       # than the canonical chain
     run: specExecute[ReorgSpec],
     spec: ReorgSpec(
-      slotsToSafe:      u256(32),
-      slotsToFinalized: u256(64),
+      slotsToSafe:      32,
+      slotsToFinalized: 64,
       timeoutSeconds:   300,
-      wdForkHeight: 8, # Genesis is Pre-Withdrawals
+      forkHeight: 8, # Genesis is Pre-Withdrawals
       wdBlockCount: 8,
       wdPerBlock:   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
-      timeIncrements:        2,
+      blockTimestampIncrement: 2,
       reOrgBlockCount:         10,
       reOrgViaSync:            true,
       sidechaintimeIncrements: 1,
@@ -94,10 +96,10 @@ let wdTestList* = [
     about: "Tests a simple 1 block re-org",
     run: specExecute[ReorgSpec],
     spec: ReorgSpec(
-      slotsToSafe:      u256(32),
-      slotsToFinalized: u256(64),
+      slotsToSafe:      32,
+      slotsToFinalized: 64,
       timeoutSeconds:   300,
-      wdForkHeight: 1, # Genesis is Pre-Withdrawals
+      forkHeight: 1, # Genesis is Pre-Withdrawals
       wdBlockCount: MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       wdPerBlock:   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       reOrgBlockCount: 1,
@@ -108,10 +110,10 @@ let wdTestList* = [
     about: "Tests a 8 block re-org using NewPayload. Re-org does not change withdrawals fork height",
     run: specExecute[ReorgSpec],
     spec: ReorgSpec(
-      slotsToSafe:      u256(32),
-      slotsToFinalized: u256(64),
+      slotsToSafe:      32,
+      slotsToFinalized: 64,
       timeoutSeconds:   300,
-      wdForkHeight: 1, # Genesis is Pre-Withdrawals
+      forkHeight: 1, # Genesis is Pre-Withdrawals
       wdBlockCount: MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       wdPerBlock:   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       reOrgBlockCount: 8,
@@ -124,10 +126,10 @@ let wdTestList* = [
         "the payload at the height of the fork\n",
     run: specExecute[ReorgSpec],
     spec: ReorgSpec(
-      slotsToSafe:      u256(32),
-      slotsToFinalized: u256(64),
+      slotsToSafe:      32,
+      slotsToFinalized: 64,
       timeoutSeconds:   300,
-      wdForkHeight: 8, # Genesis is Pre-Withdrawals
+      forkHeight: 8, # Genesis is Pre-Withdrawals
       wdBlockCount: 8,
       wdPerBlock:   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       reOrgBlockCount: 10,
@@ -140,10 +142,10 @@ let wdTestList* = [
       # than the canonical chain
     run: specExecute[ReorgSpec],
     spec: ReorgSpec(
-      slotsToSafe:      u256(32),
-      slotsToFinalized: u256(64),
+      slotsToSafe:      32,
+      slotsToFinalized: 64,
       timeoutSeconds:   300,
-      wdForkHeight: 8, # Genesis is Pre-Withdrawals
+      forkHeight: 8, # Genesis is Pre-Withdrawals
       wdBlockCount: 8,
       wdPerBlock:   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       reOrgBlockCount:         10,
@@ -157,13 +159,13 @@ let wdTestList* = [
       # than the canonical chain
     run: specExecute[ReorgSpec],
     spec: ReorgSpec(
-      slotsToSafe:      u256(32),
-      slotsToFinalized: u256(64),
+      slotsToSafe:      32,
+      slotsToFinalized: 64,
       timeoutSeconds:   300,
-      wdForkHeight: 8, # Genesis is Pre-Withdrawals
+      forkHeight: 8, # Genesis is Pre-Withdrawals
       wdBlockCount: 8,
       wdPerBlock:   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
-      timeIncrements:        2,
+      blockTimestampIncrement: 2,
       reOrgBlockCount:         10,
       reOrgViaSync:            false,
       sidechaintimeIncrements: 1,
@@ -180,7 +182,7 @@ let wdTestList* = [
     run: specExecute[SyncSpec],
     spec: SyncSpec(
       timeoutSeconds:  6,
-      wdForkHeight:    1,
+      forkHeight:    1,
       wdBlockCount:    2,
       wdPerBlock:      MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       wdAbleAccountCount: 1,
@@ -196,7 +198,7 @@ let wdTestList* = [
       "- Wait for sync and verify withdrawn account's balance\n",
     run: specExecute[SyncSpec],
     spec: SyncSpec(
-      wdForkHeight:    1,
+      forkHeight:    1,
       wdBlockCount:    2,
       wdPerBlock:      MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       wdAbleAccountCount: 1,
@@ -210,7 +212,7 @@ let wdTestList* = [
       "- Wait for sync and verify withdrawn account's balance\n",
     run: specExecute[SyncSpec],
     spec: SyncSpec(
-      wdForkHeight:    0,
+      forkHeight:    0,
       wdBlockCount:    2,
       wdPerBlock:      MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       wdAbleAccountCount: 1,
@@ -225,7 +227,7 @@ let wdTestList* = [
       "- Wait for sync, which include syncing a pre-Withdrawals block, and verify withdrawn account's balance\n",
     run: specExecute[SyncSpec],
     spec: SyncSpec(
-      wdForkHeight:    2,
+      forkHeight:    2,
       wdBlockCount:    2,
       wdPerBlock:      MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       wdAbleAccountCount: MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
@@ -241,7 +243,7 @@ let wdTestList* = [
       "- Wait for sync, which include syncing a pre-Withdrawals block, and verify withdrawn account's balance\n",
     run: specExecute[SyncSpec],
     spec: SyncSpec(
-      wdForkHeight:    2,
+      forkHeight:    2,
       wdBlockCount:    2,
       wdPerBlock:      MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       wdAbleAccountCount: MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
@@ -257,7 +259,7 @@ let wdTestList* = [
     run: specExecute[SyncSpec],
     spec: SyncSpec(
       timeoutSeconds:  100,
-      wdForkHeight:    2,
+      forkHeight:    2,
       wdBlockCount:    128,
       wdPerBlock:      MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       wdAbleAccountCount: 1024,
@@ -269,7 +271,7 @@ let wdTestList* = [
     name: "Max Initcode Size",
     run: specExecute[MaxInitcodeSizeSpec],
     spec: MaxInitcodeSizeSpec(
-      wdForkHeight: 2, # Block 1 is Pre-Withdrawals
+      forkHeight: 2, # Block 1 is Pre-Withdrawals
       wdBlockCount: 2,
       overflowMaxInitcodeTxCountBeforeFork: 0,
       overflowMaxInitcodeTxCountAfterFork:  1,
@@ -280,7 +282,7 @@ let wdTestList* = [
     about: "Verify the block value returned in GetPayloadV2.",
     run: specExecute[BlockValueSpec],
     spec: BlockValueSpec(
-      wdForkHeight: 1,
+      forkHeight: 1,
       wdBlockCount: 1,
   )),
   # Base tests
@@ -289,7 +291,7 @@ let wdTestList* = [
     about: "Tests the withdrawals fork happening since genesis (e.g. on a testnet).",
     run: specExecute[WDBaseSpec],
     spec: WDBaseSpec(
-      wdForkHeight: 0,
+      forkHeight: 0,
       wdBlockCount: 2, # Genesis is a withdrawals block
       wdPerBlock:   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
   )),
@@ -298,7 +300,7 @@ let wdTestList* = [
     about: "Tests the withdrawals fork happening directly after genesis.",
     run: specExecute[WDBaseSpec],
     spec: WDBaseSpec(
-      wdForkHeight: 1, # Only Genesis is Pre-Withdrawals
+      forkHeight: 1, # Only Genesis is Pre-Withdrawals
       wdBlockCount: 1,
       wdPerBlock:   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
   )),
@@ -309,7 +311,7 @@ let wdTestList* = [
       " client is expected to respond with the appropriate error.",
     run: specExecute[WDBaseSpec],
     spec: WDBaseSpec(
-      wdForkHeight: 2, # Genesis and Block 1 are Pre-Withdrawals
+      forkHeight: 2, # Genesis and Block 1 are Pre-Withdrawals
       wdBlockCount: 1,
       wdPerBlock:   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
   )),
@@ -320,7 +322,7 @@ let wdTestList* = [
       " client is expected to respond with the appropriate error.",
     run: specExecute[WDBaseSpec],
     spec: WDBaseSpec(
-      wdForkHeight: 3, # Genesis, Block 1 and 2 are Pre-Withdrawals
+      forkHeight: 3, # Genesis, Block 1 and 2 are Pre-Withdrawals
       wdBlockCount: 1,
       wdPerBlock:   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
   )),
@@ -329,7 +331,7 @@ let wdTestList* = [
     about: "Make multiple withdrawals to a single account.",
     run: specExecute[WDBaseSpec],
     spec: WDBaseSpec(
-      wdForkHeight:    1,
+      forkHeight:    1,
       wdBlockCount:    1,
       wdPerBlock:    MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       wdAbleAccountCount: 1,
@@ -342,7 +344,7 @@ let wdTestList* = [
       " is not in ordered sequence.",
     run: specExecute[WDBaseSpec],
     spec: WDBaseSpec(
-      wdForkHeight:    1,
+      forkHeight:    1,
       wdBlockCount:    1,
       wdPerBlock:    MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       wdAbleAccountCount: 2,
@@ -354,7 +356,7 @@ let wdTestList* = [
     # TimeoutSeconds: 240,
     run: specExecute[WDBaseSpec],
     spec: WDBaseSpec(
-      wdForkHeight:    1,
+      forkHeight:    1,
       wdBlockCount:    4,
       wdPerBlock:    MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK * 5,
       wdAbleAccountCount: 1024,
@@ -364,7 +366,7 @@ let wdTestList* = [
     about: "Make multiple withdrawals where the amount withdrawn is 0.",
     run: specExecute[WDBaseSpec],
     spec: WDBaseSpec(
-      wdForkHeight:    1,
+      forkHeight:    1,
       wdBlockCount:    1,
       wdPerBlock:    MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK,
       wdAbleAccountCount: 2,
@@ -375,7 +377,7 @@ let wdTestList* = [
     about: "Produce withdrawals block with zero withdrawals.",
     run: specExecute[WDBaseSpec],
     spec: WDBaseSpec(
-      wdForkHeight: 1,
+      forkHeight: 1,
       wdBlockCount: 1,
       wdPerBlock:   0,
   )),
@@ -384,7 +386,7 @@ let wdTestList* = [
     about: "Send a valid payload with a corrupted hash using engine_newPayloadV2.",
     run: specExecute[WDBaseSpec],
     spec: WDBaseSpec(
-      wdForkHeight:    1,
+      forkHeight:    1,
       wdBlockCount:    1,
       testCorrupedHashPayloads: true,
     )
diff --git a/hive_integration/nodocker/engine/withdrawals/wd_base_spec.nim b/hive_integration/nodocker/engine/withdrawals/wd_base_spec.nim
index ec2dab572..f0a680258 100644
--- a/hive_integration/nodocker/engine/withdrawals/wd_base_spec.nim
+++ b/hive_integration/nodocker/engine/withdrawals/wd_base_spec.nim
@@ -11,18 +11,15 @@ import
   ../test_env,
   ../engine_client,
   ../types,
+  ../base_spec,
   ../../../nimbus/common/common,
   ../../../nimbus/utils/utils,
   ../../../nimbus/common/chain_config,
   ../../../nimbus/beacon/execution_types,
   ../../../nimbus/beacon/web3_eth_conv
 
-import ../../../tools/common/helpers except LogLevel
-
 type
   WDBaseSpec* = ref object of BaseSpec
-    timeIncrements*:     int          # Timestamp increments per block throughout the test
-    wdForkHeight*:       int          # Withdrawals activation fork height
     wdBlockCount*:       int          # Number of blocks on and after withdrawals fork activation
     wdPerBlock*:         int          # Number of withdrawals per block
     wdAbleAccountCount*: int          # Number of accounts to withdraw to (round-robin)
@@ -37,7 +34,6 @@ type
     nextIndex*: int
 
 const
-  GenesisTimestamp = 0x1234
   WARM_COINBASE_ADDRESS = hexToByteArray[20]("0x0101010101010101010101010101010101010101")
   PUSH0_ADDRESS         = hexToByteArray[20]("0x0202020202020202020202020202020202020202")
   MAINNET_MAX_WITHDRAWAL_COUNT_PER_BLOCK* = 16
@@ -46,34 +42,14 @@ const
     PUSH0_ADDRESS,
   ]
 
-# Get the per-block timestamp increments configured for this test
-func getBlockTimeIncrements*(ws: WDBaseSpec): int =
-  if ws.timeIncrements == 0:
-    return 1
-  ws.timeIncrements
-
 # Timestamp delta between genesis and the withdrawals fork
 func getWithdrawalsGenesisTimeDelta*(ws: WDBaseSpec): int =
-  ws.wdForkHeight * ws.getBlockTimeIncrements()
-
-# Calculates Shanghai fork timestamp given the amount of blocks that need to be
-# produced beforehand.
-func getWithdrawalsForkTime(ws: WDBaseSpec): int =
-  GenesisTimestamp + ws.getWithdrawalsGenesisTimeDelta()
-
-# Generates the fork config, including withdrawals fork timestamp.
-func getForkConfig*(ws: WDBaseSpec): ChainConfig =
-  result = getChainConfig("Shanghai")
-  result.shanghaiTime = some(ws.getWithdrawalsForkTime().EthTime)
+  ws.forkHeight * ws.getBlockTimeIncrements()
 
 # Get the start account for all withdrawals.
 func getWithdrawalsStartAccount*(ws: WDBaseSpec): UInt256 =
   0x1000.u256
 
-func toAddress(x: UInt256): EthAddress =
-  var mm = x.toByteArrayBE
-  copyMem(result[0].addr, mm[11].addr, 20)
-
 # Adds bytecode that unconditionally sets an storage key to specified account range
 func addUnconditionalBytecode(g: Genesis, start, stop: UInt256) =
   var acc = start
@@ -177,7 +153,7 @@ proc verifyContractsStorage(ws: WDBaseSpec, env: TestEnv): Result[void, string]
     r = env.client.storageAt(WARM_COINBASE_ADDRESS, latestPayloadNumber, latestPayloadNumber)
     p = env.client.storageAt(PUSH0_ADDRESS, 0.u256, latestPayloadNumber)
 
-  if latestPayloadNumber.truncate(int) >= ws.wdForkHeight:
+  if latestPayloadNumber.truncate(int) >= ws.forkHeight:
     # Shanghai
     r.expectStorageEqual(WARM_COINBASE_ADDRESS, 100.u256)    # WARM_STORAGE_READ_COST
     p.expectStorageEqual(PUSH0_ADDRESS, latestPayloadNumber) # tx succeeded
@@ -188,18 +164,13 @@ proc verifyContractsStorage(ws: WDBaseSpec, env: TestEnv): Result[void, string]
 
   ok()
 
-# Changes the CL Mocker default time increments of 1 to the value specified
-# in the test spec.
-proc configureCLMock*(ws: WDBaseSpec, cl: CLMocker) =
-  cl.blockTimestampIncrement = some(ws.getBlockTimeIncrements())
-
 # Number of blocks to be produced (not counting genesis) before withdrawals
 # fork.
 func getPreWithdrawalsBlockCount*(ws: WDBaseSpec): int =
-  if ws.wdForkHeight == 0:
+  if ws.forkHeight == 0:
     0
   else:
-    ws.wdForkHeight - 1
+    ws.forkHeight - 1
 
 # Number of payloads to be produced (pre and post withdrawals) during the entire test
 func getTotalPayloadCount*(ws: WDBaseSpec): int =
@@ -235,7 +206,7 @@ proc execute*(ws: WDBaseSpec, env: TestEnv): bool =
   testCond ok
 
   # Check if we have pre-Shanghai blocks
-  if ws.getWithdrawalsForkTime() > GenesisTimestamp:
+  if ws.getForkTime() > GenesisTimestamp:
     # Check `latest` during all pre-shanghai blocks, none should
     # contain `withdrawalsRoot`, including genesis.
 
@@ -538,7 +509,7 @@ proc execute*(ws: WDBaseSpec, env: TestEnv): bool =
       let r = env.client.headerByNumber(bn, h)
 
       var expectedWithdrawalsRoot: Option[common.Hash256]
-      if bn >= ws.wdForkHeight.uint64:
+      if bn >= ws.forkHeight.uint64:
         let wds = ws.wdHistory.getWithdrawals(bn)
         expectedWithdrawalsRoot = some(calcWithdrawalsRoot(wds.list))
 
diff --git a/hive_integration/nodocker/engine/withdrawals/wd_reorg_spec.nim b/hive_integration/nodocker/engine/withdrawals/wd_reorg_spec.nim
index fc3e708ca..39f3bd6db 100644
--- a/hive_integration/nodocker/engine/withdrawals/wd_reorg_spec.nim
+++ b/hive_integration/nodocker/engine/withdrawals/wd_reorg_spec.nim
@@ -9,6 +9,7 @@ import
   ../test_env,
   ../engine_client,
   ../types,
+  ../base_spec,
   ../../../nimbus/beacon/web3_eth_conv
 
 # Withdrawals re-org spec:
@@ -22,9 +23,6 @@ type
     # Whether the client should fetch the sidechain by syncing from the secondary client
     reOrgViaSync*           : bool
     sidechainTimeIncrements*: int
-    slotsToSafe*            : UInt256
-    slotsToFinalized*       : UInt256
-    timeoutSeconds*         : int
 
   Sidechain = ref object
     startAccount: UInt256
@@ -48,14 +46,14 @@ proc getSidechainBlockTimeIncrements(ws: ReorgSpec): int=
     return ws.getBlockTimeIncrements()
   ws.sidechainTimeIncrements
 
-proc getSidechainWdForkHeight(ws: ReorgSpec): int =
+proc getSidechainforkHeight(ws: ReorgSpec): int =
   if ws.getSidechainBlockTimeIncrements() != ws.getBlockTimeIncrements():
     # Block timestamp increments in both chains are different so need to
     # calculate different heights, only if split happens before fork.
     # We cannot split by having two different genesis blocks.
     doAssert(ws.getSidechainSplitHeight() != 0, "invalid sidechain split height")
 
-    if ws.getSidechainSplitHeight() <= ws.wdForkHeight:
+    if ws.getSidechainSplitHeight() <= ws.forkHeight:
       # We need to calculate the height of the fork on the sidechain
       let sidechainSplitBlocktimestamp = (ws.getSidechainSplitHeight() - 1) * ws.getBlockTimeIncrements()
       let remainingTime = ws.getWithdrawalsGenesisTimeDelta() - sidechainSplitBlocktimestamp
@@ -64,7 +62,7 @@ proc getSidechainWdForkHeight(ws: ReorgSpec): int =
 
       return ((remainingTime - 1) div ws.sidechainTimeIncrements) + ws.getSidechainSplitHeight()
 
-  return ws.wdForkHeight
+  return ws.forkHeight
 
 proc execute*(ws: ReorgSpec, env: TestEnv): bool =
   result = true
@@ -94,7 +92,7 @@ proc execute*(ws: ReorgSpec, env: TestEnv): bool =
     onPayloadProducerSelected: proc(): bool =
       env.clMock.nextWithdrawals = none(seq[WithdrawalV1])
 
-      if env.clMock.currentPayloadNumber >= ws.wdForkHeight.uint64:
+      if env.clMock.currentPayloadNumber >= ws.forkHeight.uint64:
         # Prepare some withdrawals
         let wfb = ws.generateWithdrawalsForBlock(canonical.nextIndex, canonical.startAccount)
         env.clMock.nextWithdrawals = some(w3Withdrawals wfb.wds)
@@ -103,7 +101,7 @@ proc execute*(ws: ReorgSpec, env: TestEnv): bool =
 
       if env.clMock.currentPayloadNumber >= ws.getSidechainSplitHeight().uint64:
         # We have split
-        if env.clMock.currentPayloadNumber >= ws.getSidechainWdForkHeight().uint64:
+        if env.clMock.currentPayloadNumber >= ws.getSidechainforkHeight().uint64:
           # And we are past the withdrawals fork on the sidechain
           let wfb = ws.generateWithdrawalsForBlock(sidechain.nextIndex, sidechain.startAccount)
           sidechain.wdHistory.put(env.clMock.currentPayloadNumber, wfb.wds)
@@ -156,7 +154,7 @@ proc execute*(ws: ReorgSpec, env: TestEnv): bool =
         else:
           attr.timestamp = env.clMock.latestPayloadAttributes.timestamp
 
-        if env.clMock.currentPayloadNumber >= ws.getSidechainwdForkHeight().uint64:
+        if env.clMock.currentPayloadNumber >= ws.getSidechainforkHeight().uint64:
           # Withdrawals
           let rr = sidechain.wdHistory.get(env.clMock.currentPayloadNumber)
           testCond rr.isOk:
@@ -207,12 +205,12 @@ proc execute*(ws: ReorgSpec, env: TestEnv): bool =
 
   sidechain.height = env.clMock.latestExecutedPayload.blockNumber.uint64
 
-  if ws.wdForkHeight < ws.getSidechainwdForkHeight():
+  if ws.forkHeight < ws.getSidechainforkHeight():
     # This means the canonical chain forked before the sidechain.
     # Therefore we need to produce more sidechain payloads to reach
     # at least`ws.WithdrawalsBlockCount` withdrawals payloads produced on
     # the sidechain.
-    let height = ws.getSidechainwdForkHeight()-ws.wdForkHeight
+    let height = ws.getSidechainforkHeight()-ws.forkHeight
     for i in 0..<height:
       let
         wfb = ws.generateWithdrawalsForBlock(sidechain.nextIndex, sidechain.startAccount)
@@ -296,7 +294,7 @@ proc execute*(ws: ReorgSpec, env: TestEnv): bool =
     while payloadNumber.uint64 <= sidechain.height:
       let payload = sidechain.sidechain[payloadNumber.uint64]
       var version = Version.V1
-      if payloadNumber >= ws.getSidechainwdForkHeight():
+      if payloadNumber >= ws.getSidechainforkHeight():
         version = Version.V2
 
       info "Sending sidechain",
@@ -322,7 +320,7 @@ proc execute*(ws: ReorgSpec, env: TestEnv): bool =
   # We are using different accounts credited between the canonical chain
   # and the fork.
   # We check on `latest`.
-  let r3 = ws.wdHistory.verifyWithdrawals(uint64(ws.wdForkHeight-1), none(UInt256), env.client)
+  let r3 = ws.wdHistory.verifyWithdrawals(uint64(ws.forkHeight-1), none(UInt256), env.client)
   testCond r3.isOk
 
   # Re-Org back to the canonical chain
diff --git a/hive_integration/nodocker/engine/withdrawals/wd_sync_spec.nim b/hive_integration/nodocker/engine/withdrawals/wd_sync_spec.nim
index d5f2c9204..5b613ac3c 100644
--- a/hive_integration/nodocker/engine/withdrawals/wd_sync_spec.nim
+++ b/hive_integration/nodocker/engine/withdrawals/wd_sync_spec.nim
@@ -14,7 +14,6 @@ type
   SyncSpec* = ref object of WDBaseSpec
     syncSteps*: int  # Sync block chunks that will be passed as head through FCUs to the syncing client
     syncShouldFail*: bool
-    timeoutSeconds*: int
     sleep*: int
 
 proc doSync(ws: SyncSpec, client: RpcClient, clMock: CLMocker): Future[bool] {.async.} =
diff --git a/nimbus/constants.nim b/nimbus/constants.nim
index 2a774d310..491e4df92 100644
--- a/nimbus/constants.nim
+++ b/nimbus/constants.nim
@@ -85,7 +85,7 @@ const
   BLOB_GASPRICE_UPDATE_FRACTION* = 3338477'u64
   MAX_BLOB_GAS_PER_BLOCK* = 786432
   MAX_ALLOWED_BLOB* = MAX_BLOB_GAS_PER_BLOCK div GAS_PER_BLOB
-
+  
   # EIP-4788 addresses
   # BEACON_ROOTS_ADDRESS is the address where historical beacon roots are stored as per EIP-4788
   BEACON_ROOTS_ADDRESS* = hexToByteArray[20]("0x000F3df6D732807Ef1319fB7B8bB8522d0Beac02")