diff --git a/beacon_chain/beacon_node.nim b/beacon_chain/beacon_node.nim
index 49c7d327e3..e442fdb49e 100644
--- a/beacon_chain/beacon_node.nim
+++ b/beacon_chain/beacon_node.nim
@@ -51,6 +51,7 @@ type
     finalQueue*: AsyncEventQueue[FinalizationInfoObject]
     reorgQueue*: AsyncEventQueue[ReorgInfoObject]
     contribQueue*: AsyncEventQueue[SignedContributionAndProof]
+    payloadAttributesQueue*: AsyncEventQueue[PayloadAttributesInfoObject]
     finUpdateQueue*: AsyncEventQueue[
       RestVersioned[ForkedLightClientFinalityUpdate]]
     optUpdateQueue*: AsyncEventQueue[
diff --git a/beacon_chain/consensus_object_pools/block_dag.nim b/beacon_chain/consensus_object_pools/block_dag.nim
index 6dd2bc0eb3..163f04a845 100644
--- a/beacon_chain/consensus_object_pools/block_dag.nim
+++ b/beacon_chain/consensus_object_pools/block_dag.nim
@@ -35,6 +35,7 @@ type
       ## Root that can be used to retrieve block data from database
 
     executionBlockHash*: Opt[Eth2Digest]
+    executionBlockNumber*: Opt[uint64]
     executionValid*: bool
 
     parent*: BlockRef ##\
@@ -55,11 +56,12 @@ template slot*(blck: BlockRef): Slot = blck.bid.slot
 
 func init*(
     T: type BlockRef, root: Eth2Digest,
-    executionBlockHash: Opt[Eth2Digest], executionValid: bool, slot: Slot):
-    BlockRef =
+    executionBlockHash: Opt[Eth2Digest], executionBlockNumber: Opt[uint64],
+    executionValid: bool, slot: Slot): BlockRef =
   BlockRef(
     bid: BlockId(root: root, slot: slot),
-    executionBlockHash: executionBlockHash, executionValid: executionValid)
+    executionBlockHash: executionBlockHash,
+    executionBlockNumber: executionBlockNumber, executionValid: executionValid)
 
 func init*(
     T: type BlockRef, root: Eth2Digest, executionValid: bool,
@@ -67,7 +69,8 @@ func init*(
           phase0.TrustedBeaconBlock | altair.TrustedBeaconBlock): BlockRef =
   # Use same formal parameters for simplicity, but it's impossible for these
   # blocks to be optimistic.
-  BlockRef.init(root, Opt.some ZERO_HASH, executionValid = true, blck.slot)
+  BlockRef.init(
+    root, Opt.some ZERO_HASH, Opt.some 0'u64, executionValid = true, blck.slot)
 
 func init*(
     T: type BlockRef, root: Eth2Digest, executionValid: bool,
@@ -76,6 +79,7 @@ func init*(
           deneb.SomeBeaconBlock | deneb.TrustedBeaconBlock): BlockRef =
   BlockRef.init(
     root, Opt.some Eth2Digest(blck.body.execution_payload.block_hash),
+    Opt.some blck.body.execution_payload.block_number,
     executionValid =
       executionValid or blck.body.execution_payload.block_hash == ZERO_HASH,
     blck.slot)
diff --git a/beacon_chain/consensus_object_pools/blockchain_dag.nim b/beacon_chain/consensus_object_pools/blockchain_dag.nim
index 8a92dab87d..89688cf1cd 100644
--- a/beacon_chain/consensus_object_pools/blockchain_dag.nim
+++ b/beacon_chain/consensus_object_pools/blockchain_dag.nim
@@ -1020,7 +1020,7 @@ proc init*(T: type ChainDAGRef, cfg: RuntimeConfig, db: BeaconChainDB,
     # `VALID` fcU from an EL plus markBlockVerified. Pre-merge blocks still get
     # marked as `VALID`.
     let newRef = BlockRef.init(
-      blck.root, Opt.none Eth2Digest, executionValid = false,
+      blck.root, Opt.none Eth2Digest, Opt.none uint64, executionValid = false,
       blck.summary.slot)
     if headRef == nil:
       headRef = newRef
@@ -2226,21 +2226,38 @@ proc pruneHistory*(dag: ChainDAGRef, startup = false) =
           if dag.db.clearBlocks(fork):
             break
 
-proc loadExecutionBlockHash*(dag: ChainDAGRef, bid: BlockId): Eth2Digest =
+proc loadExecutionBlockHashAndNumber(dag: ChainDAGRef, bid: BlockId):
+    (Eth2Digest, uint64) =
   let blockData = dag.getForkedBlock(bid).valueOr:
-    return ZERO_HASH
+    return (ZERO_HASH, 0)
 
   withBlck(blockData):
     when consensusFork >= ConsensusFork.Bellatrix:
-      forkyBlck.message.body.execution_payload.block_hash
+      (forkyBlck.message.body.execution_payload.block_hash,
+       forkyBlck.message.body.execution_payload.block_number)
     else:
-      ZERO_HASH
+      (ZERO_HASH, 0)
+
+proc loadExecutionBlockHash*(dag: ChainDAGRef, bid: BlockId): Eth2Digest =
+  let (executionBlockHash, _) = dag.loadExecutionBlockHashAndNumber(bid)
+  executionBlockHash
+
+proc ensureExecutionBlockHashAndNumberLoaded(dag: ChainDAGRef, blck: BlockRef) =
+  # The expensive part is loading the block, not copying a few additional bytes
+  if blck.executionBlockHash.isNone or blck.executionBlockNumber.isNone:
+    let (executionBlockHash, executionBlockNumber) =
+      dag.loadExecutionBlockHashAndNumber(blck.bid)
+    blck.executionBlockHash = Opt.some executionBlockHash
+    blck.executionBlockNumber = Opt.some executionBlockNumber
 
 proc loadExecutionBlockHash*(dag: ChainDAGRef, blck: BlockRef): Eth2Digest =
-  if blck.executionBlockHash.isNone:
-    blck.executionBlockHash = Opt.some dag.loadExecutionBlockHash(blck.bid)
+  dag.ensureExecutionBlockHashAndNumberLoaded(blck)
   blck.executionBlockHash.unsafeGet
 
+proc loadExecutionBlockNumber*(dag: ChainDAGRef, blck: BlockRef): uint64 =
+  dag.ensureExecutionBlockHashAndNumberLoaded(blck)
+  blck.executionBlockNumber.unsafeGet
+
 from std/packedsets import PackedSet, incl, items
 
 func getValidatorChangeStatuses(
diff --git a/beacon_chain/fork_choice/fork_choice.nim b/beacon_chain/fork_choice/fork_choice.nim
index fd8f485ecc..dff22acf44 100644
--- a/beacon_chain/fork_choice/fork_choice.nim
+++ b/beacon_chain/fork_choice/fork_choice.nim
@@ -87,16 +87,15 @@ func extend[T](s: var seq[T], minLen: int) =
 
 proc update_justified(
     self: var Checkpoints, dag: ChainDAGRef, blck: BlockRef, epoch: Epoch) =
-  let
-    epochRef = dag.getEpochRef(blck, epoch, false).valueOr:
-      # Shouldn't happen for justified data unless out of sync with ChainDAG
-      warn "Skipping justified checkpoint update, no EpochRef - report bug",
-        blck, epoch, error
-      return
-    justified = Checkpoint(root: blck.root, epoch: epochRef.epoch)
+  let epochRef = dag.getEpochRef(blck, epoch, false).valueOr:
+    # Shouldn't happen for justified data unless out of sync with ChainDAG
+    warn "Skipping justified checkpoint update, no EpochRef - report bug",
+      blck, epoch, error
+    return
 
   trace "Updating justified",
-    store = self.justified.checkpoint, state = justified
+    store = self.justified.checkpoint,
+    state = Checkpoint(root: blck.root, epoch: epochRef.epoch)
   self.justified = BalanceCheckpoint(
     checkpoint: Checkpoint(root: blck.root, epoch: epochRef.epoch),
     total_active_balance: epochRef.total_active_balance,
diff --git a/beacon_chain/gossip_processing/block_processor.nim b/beacon_chain/gossip_processing/block_processor.nim
index 3cc34f1929..a013212d4d 100644
--- a/beacon_chain/gossip_processing/block_processor.nim
+++ b/beacon_chain/gossip_processing/block_processor.nim
@@ -10,7 +10,8 @@
 import
   stew/results,
   chronicles, chronos, metrics,
-  ../spec/[signatures, signatures_batch],
+  ../spec/[
+    eth2_apis/eth2_rest_serialization, signatures, signatures_batch],
   ../sszdump
 
 from std/deques import Deque, addLast, contains, initDeque, items, len, shrink
@@ -21,7 +22,7 @@ from ../consensus_object_pools/consensus_manager import
   updateHeadWithExecution
 from ../consensus_object_pools/blockchain_dag import
   getBlockRef, getProposer, forkAtEpoch, loadExecutionBlockHash,
-  markBlockVerified, validatorKey
+  loadExecutionBlockNumber, markBlockVerified, validatorKey
 from ../beacon_clock import GetBeaconTimeFn, toFloatSeconds
 from ../consensus_object_pools/block_dag import BlockRef, root, shortLog, slot
 from ../consensus_object_pools/block_pools_types import
@@ -66,6 +67,9 @@ type
     validationDur*: Duration # Time it took to perform gossip validation
     src*: MsgSource
 
+  OnPayloadAttributesCallback =
+    proc(data: PayloadAttributesInfoObject) {.gcsafe, raises: [].}
+
   BlockProcessor* = object
     ## This manages the processing of blocks from different sources
     ## Blocks and attestations are enqueued in a gossip-validated state
@@ -109,6 +113,10 @@ type
       ## The slot at which we sent a payload to the execution client the last
       ## time
 
+    # SSE callback
+    # ----------------------------------------------------------------
+    onPayloadAttributesAdded: OnPayloadAttributesCallback
+
   NewPayloadStatus {.pure.} = enum
     valid
     notValid
@@ -129,7 +137,9 @@ proc new*(T: type BlockProcessor,
           consensusManager: ref ConsensusManager,
           validatorMonitor: ref ValidatorMonitor,
           blobQuarantine: ref BlobQuarantine,
-          getBeaconTime: GetBeaconTimeFn): ref BlockProcessor =
+          getBeaconTime: GetBeaconTimeFn,
+          onPayloadAttributesAdded: OnPayloadAttributesCallback):
+          ref BlockProcessor =
   (ref BlockProcessor)(
     dumpEnabled: dumpEnabled,
     dumpDirInvalid: dumpDirInvalid,
@@ -139,6 +149,7 @@ proc new*(T: type BlockProcessor,
     validatorMonitor: validatorMonitor,
     blobQuarantine: blobQuarantine,
     getBeaconTime: getBeaconTime,
+    onPayloadAttributesAdded: onPayloadAttributesAdded,
     verifier: BatchVerifier.init(rng, taskpool)
   )
 
@@ -407,6 +418,52 @@ proc enqueueBlock*(
   except AsyncQueueFullError:
     raiseAssert "unbounded queue"
 
+proc sendNewPayloadAttributeNotification(
+    self: BlockProcessor, wallSlot: Slot, newHead: BlockRef) =
+  if not(isNil(self.onPayloadAttributesAdded)):
+    # https://github.com/ethereum/beacon-APIs/blob/v2.4.2/apis/eventstream/index.yaml#L95-L124
+    # `payload_attributes`: beacon API encoding of `PayloadAttributesV<N>` as
+    # defined by the `execution-apis` specification. The version `N` must match
+    # the payload attributes for the hard fork matching `version`.
+    #
+    # The beacon API encoded object must have equivalent fields to its
+    # counterpart in `execution-apis` with two differences: 1) `snake_case`
+    # identifiers must be used rather than `camelCase`; 2) integers must be
+    # encoded as quoted decimals rather than big-endian hex.
+    let
+      proposal_slot = wallSlot + 1
+      payload_attributes =
+        case self.consensusManager.dag.cfg.consensusForkAtEpoch(
+            proposal_slot.epoch)
+        of ConsensusFork.Deneb:
+          RestJson.encode(RestPayloadAttributesV3(
+            timestamp: 0'u64,
+            prev_randao: ZERO_HASH,
+            suggested_fee_recipient: default(Eth1Address),
+            withdrawals: @[],
+            parent_beacon_block_root: ZERO_HASH))
+        of ConsensusFork.Capella:
+          RestJson.encode(RestPayloadAttributesV2(
+            timestamp: 0'u64,
+            prev_randao: ZERO_HASH,
+            suggested_fee_recipient: default(Eth1Address),
+            withdrawals: @[]))
+        of ConsensusFork.Phase0 .. ConsensusFork.Bellatrix:
+          RestJson.encode(RestPayloadAttributesV1(
+            timestamp: 0'u64,
+            prev_randao: ZERO_HASH,
+            suggested_fee_recipient: default(Eth1Address)))
+
+    self.onPayloadAttributesAdded(PayloadAttributesInfoObject(
+      proposal_slot: proposal_slot,
+      parent_block_root: newHead.root,
+      parent_block_number:
+        self.consensusManager.dag.loadExecutionBlockNumber(newHead),
+      parent_block_hash:
+        self.consensusManager.dag.loadExecutionBlockHash(newHead),
+      proposer_index: 0'u64,  # FIXME
+      payload_attributes: payload_attributes))
+
 proc storeBlock(
     self: ref BlockProcessor, src: MsgSource, wallTime: BeaconTime,
     signedBlock: ForkySignedBeaconBlock,
@@ -654,6 +711,7 @@ proc storeBlock(
         headExecutionPayloadHash =
           dag.loadExecutionBlockHash(newHead.get.blck)
         wallSlot = self.getBeaconTime().slotOrZero
+
       if  headExecutionPayloadHash.isZero or
           NewPayloadStatus.noResponse == payloadStatus:
         # Blocks without execution payloads can't be optimistic, and don't try
@@ -682,6 +740,8 @@ proc storeBlock(
               ConsensusFork.Bellatrix:
             callExpectValidFCU(payloadAttributeType = PayloadAttributesV1)
 
+        self[].sendNewPayloadAttributeNotification(wallSlot, newHead.get.blck)
+
         if self.consensusManager.checkNextProposer(wallSlot).isNone:
           # No attached validator is next proposer, so use non-proposal fcU
           callForkChoiceUpdated()
@@ -695,6 +755,9 @@ proc storeBlock(
       else:
         await self.consensusManager.updateHeadWithExecution(
           newHead.get, self.getBeaconTime)
+
+        self[].sendNewPayloadAttributeNotification(wallSlot, newHead.get.blck)
+
   else:
     warn "Head selection failed, using previous head",
       head = shortLog(dag.head), wallSlot
diff --git a/beacon_chain/gossip_processing/gossip_validation.nim b/beacon_chain/gossip_processing/gossip_validation.nim
index 71968278b0..1ae0595134 100644
--- a/beacon_chain/gossip_processing/gossip_validation.nim
+++ b/beacon_chain/gossip_processing/gossip_validation.nim
@@ -254,10 +254,6 @@ template checkedReject(
     pool: ValidatorChangePool, error: ValidationError): untyped =
   pool.dag.checkedReject(error)
 
-template checkedResult(
-    pool: ValidatorChangePool, error: ValidationError): untyped =
-  pool.dag.checkedResult(error)
-
 template validateBeaconBlockBellatrix(
     signed_beacon_block: phase0.SignedBeaconBlock | altair.SignedBeaconBlock,
     parent: BlockRef): untyped =
diff --git a/beacon_chain/nimbus_beacon_node.nim b/beacon_chain/nimbus_beacon_node.nim
index 66d2ff8660..358dfa79e1 100644
--- a/beacon_chain/nimbus_beacon_node.nim
+++ b/beacon_chain/nimbus_beacon_node.nim
@@ -251,6 +251,8 @@ proc initFullNode(
     node.eventBus.propSlashQueue.emit(data)
   proc onAttesterSlashingAdded(data: AttesterSlashing) =
     node.eventBus.attSlashQueue.emit(data)
+  proc onPayloadAttributesAdded(data: PayloadAttributesInfoObject) =
+    node.eventBus.payloadAttributesQueue.emit(data)
   proc onBlobSidecarAdded(data: BlobSidecar) =
     node.eventBus.blobSidecarQueue.emit(
       BlobSidecarInfoObject(
@@ -349,7 +351,7 @@ proc initFullNode(
     blockProcessor = BlockProcessor.new(
       config.dumpEnabled, config.dumpDirInvalid, config.dumpDirIncoming,
       rng, taskpool, consensusManager, node.validatorMonitor,
-      blobQuarantine, getBeaconTime)
+      blobQuarantine, getBeaconTime, onPayloadAttributesAdded)
     blockVerifier = proc(signedBlock: ForkedSignedBeaconBlock,
                          blobs: Opt[BlobSidecars], maybeFinalized: bool):
         Future[Result[void, VerifierError]] =
diff --git a/beacon_chain/rpc/rest_event_api.nim b/beacon_chain/rpc/rest_event_api.nim
index 9fa70a3208..79b4878fc3 100644
--- a/beacon_chain/rpc/rest_event_api.nim
+++ b/beacon_chain/rpc/rest_event_api.nim
@@ -146,6 +146,10 @@ proc installEventApiHandlers*(router: var RestRouter, node: BeaconNode) =
           let handler = response.eventHandler(node.eventBus.attSlashQueue,
                                               "attester_slashing")
           res.add(handler)
+        if EventTopic.PayloadAttributes in eventTopics:
+          let handler = response.eventHandler(node.eventBus.payloadAttributesQueue,
+                                              "payload_attributes")
+          res.add(handler)
         if EventTopic.BlobSidecar in eventTopics:
           let handler = response.eventHandler(node.eventBus.blobSidecarQueue,
                                               "blob_sidecar")
diff --git a/beacon_chain/spec/datatypes/deneb.nim b/beacon_chain/spec/datatypes/deneb.nim
index b579349827..5c613f7ab5 100644
--- a/beacon_chain/spec/datatypes/deneb.nim
+++ b/beacon_chain/spec/datatypes/deneb.nim
@@ -822,3 +822,13 @@ template asTrusted*(
        SigVerifiedSignedBeaconBlock |
        MsgTrustedSignedBeaconBlock): TrustedSignedBeaconBlock =
   isomorphicCast[TrustedSignedBeaconBlock](x)
+
+type
+  # https://github.com/ethereum/beacon-APIs/blob/v2.4.2/apis/eventstream/index.yaml#L95-L124
+  PayloadAttributesInfoObject* = object
+    proposal_slot*: Slot
+    parent_block_root*: Eth2Digest
+    parent_block_number*: uint64
+    parent_block_hash*: Eth2Digest
+    proposer_index*: uint64
+    payload_attributes*: string
diff --git a/beacon_chain/spec/eth2_apis/eth2_rest_serialization.nim b/beacon_chain/spec/eth2_apis/eth2_rest_serialization.nim
index c45079a13e..f0e93111ca 100644
--- a/beacon_chain/spec/eth2_apis/eth2_rest_serialization.nim
+++ b/beacon_chain/spec/eth2_apis/eth2_rest_serialization.nim
@@ -109,6 +109,7 @@ RestJson.useDefaultSerializationFor(
   KeystoreInfo,
   ListFeeRecipientResponse,
   ListGasLimitResponse,
+  PayloadAttributesInfoObject,
   PendingAttestation,
   PostKeystoresResponse,
   PrepareBeaconProposer,
@@ -141,6 +142,9 @@ RestJson.useDefaultSerializationFor(
   RestNodeExtraData,
   RestNodePeer,
   RestNodeVersion,
+  RestPayloadAttributesV1,
+  RestPayloadAttributesV2,
+  RestPayloadAttributesV3,
   RestPeerCount,
   RestProposerDuty,
   RestRoot,
@@ -307,8 +311,12 @@ type
     ImportDistributedKeystoresBody |
     ImportRemoteKeystoresBody |
     KeystoresAndSlashingProtection |
+    PayloadAttributesInfoObject |
     PrepareBeaconProposer |
     ProposerSlashing |
+    RestPayloadAttributesV1 |
+    RestPayloadAttributesV2 |
+    RestPayloadAttributesV3 |
     SetFeeRecipientRequest |
     SetGasLimitRequest |
     bellatrix_mev.SignedBlindedBeaconBlock |
@@ -4175,6 +4183,8 @@ proc decodeString*(t: typedesc[EventTopic],
     ok(EventTopic.ProposerSlashing)
   of "attester_slashing":
     ok(EventTopic.AttesterSlashing)
+  of "payload_attributes":
+    ok(EventTopic.PayloadAttributes)
   of "blob_sidecar":
     ok(EventTopic.BlobSidecar)
   of "finalized_checkpoint":
@@ -4206,6 +4216,8 @@ proc encodeString*(value: set[EventTopic]): Result[string, cstring] =
     res.add("proposer_slashing,")
   if EventTopic.AttesterSlashing in value:
     res.add("attester_slashing,")
+  if EventTopic.PayloadAttributes in value:
+    res.add("payload_attributes,")
   if EventTopic.BlobSidecar in value:
     res.add("blob_sidecar,")
   if EventTopic.FinalizedCheckpoint in value:
diff --git a/beacon_chain/spec/eth2_apis/rest_types.nim b/beacon_chain/spec/eth2_apis/rest_types.nim
index 627586eecc..8f505743ae 100644
--- a/beacon_chain/spec/eth2_apis/rest_types.nim
+++ b/beacon_chain/spec/eth2_apis/rest_types.nim
@@ -55,9 +55,9 @@ type
   # https://github.com/ethereum/beacon-APIs/blob/v2.4.2/apis/eventstream/index.yaml
   EventTopic* {.pure.} = enum
     Head, Block, Attestation, VoluntaryExit, BLSToExecutionChange,
-    ProposerSlashing, AttesterSlashing, BlobSidecar, FinalizedCheckpoint,
-    ChainReorg, ContributionAndProof, LightClientFinalityUpdate,
-    LightClientOptimisticUpdate
+    ProposerSlashing, AttesterSlashing, PayloadAttributes, BlobSidecar,
+    FinalizedCheckpoint, ChainReorg, ContributionAndProof,
+    LightClientFinalityUpdate, LightClientOptimisticUpdate
 
   EventTopics* = set[EventTopic]
 
@@ -318,6 +318,26 @@ type
     blob_gas_used*: Option[uint64]   ## [New in Deneb]
     excess_blob_gas*: Option[uint64] ## [New in Deneb]
 
+  # https://github.com/ethereum/execution-apis/blob/v1.0.0-beta.3/src/engine/paris.md#payloadattributesv1
+  RestPayloadAttributesV1* = object
+    timestamp*: uint64
+    prev_randao*: Eth2Digest
+    suggested_fee_recipient*: Eth1Address
+
+  # https://github.com/ethereum/execution-apis/blob/v1.0.0-beta.3/src/engine/shanghai.md#payloadattributesv2
+  RestPayloadAttributesV2* = object
+    timestamp*: uint64
+    prev_randao*: Eth2Digest
+    suggested_fee_recipient*: Eth1Address
+    withdrawals*: seq[Withdrawal]
+
+  # https://github.com/ethereum/execution-apis/blob/ee3df5bc38f28ef35385cefc9d9ca18d5e502778/src/engine/cancun.md#payloadattributesv3
+  RestPayloadAttributesV3* = object
+    timestamp*: uint64
+    prev_randao*: Eth2Digest
+    suggested_fee_recipient*: Eth1Address
+    withdrawals*: seq[Withdrawal]
+    parent_beacon_block_root*: Eth2Digest
 
   PrepareBeaconProposer* = object
     validator_index*: ValidatorIndex
diff --git a/tests/test_block_processor.nim b/tests/test_block_processor.nim
index 7b7f11f0e3..0d238c0e6f 100644
--- a/tests/test_block_processor.nim
+++ b/tests/test_block_processor.nim
@@ -56,7 +56,7 @@ suite "Block processor" & preset():
       getTimeFn = proc(): BeaconTime = b2.message.slot.start_beacon_time()
       processor = BlockProcessor.new(
         false, "", "", rng, taskpool, consensusManager,
-        validatorMonitor, blobQuarantine, getTimeFn)
+        validatorMonitor, blobQuarantine, getTimeFn, nil)
       processorFut = processor.runQueueProcessingLoop()
 
   asyncTest "Reverse order block add & get" & preset():