diff --git a/apis/beacon/blocks/attestations.yaml b/apis/beacon/blocks/attestations.yaml
index a0c10666..2f6bf81e 100644
--- a/apis/beacon/blocks/attestations.yaml
+++ b/apis/beacon/blocks/attestations.yaml
@@ -18,6 +18,8 @@ get:
             title: GetBlockAttestationsResponse
             type: object
             properties:
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 type: array
                 items:
diff --git a/apis/beacon/blocks/block.v2.yaml b/apis/beacon/blocks/block.v2.yaml
index edccb3d3..de8613b2 100644
--- a/apis/beacon/blocks/block.v2.yaml
+++ b/apis/beacon/blocks/block.v2.yaml
@@ -26,6 +26,8 @@ get:
                 type: string
                 enum: [phase0, altair]
                 example: "phase0"
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 oneOf:
                   - $ref: "../../../beacon-node-oapi.yaml#/components/schemas/SignedBeaconBlock"
diff --git a/apis/beacon/blocks/header.yaml b/apis/beacon/blocks/header.yaml
index 4f7e39ab..69533b1f 100644
--- a/apis/beacon/blocks/header.yaml
+++ b/apis/beacon/blocks/header.yaml
@@ -17,6 +17,8 @@ get:
             title: GetBlockHeaderResponse
             type: object
             properties:
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 type: object
                 properties:
diff --git a/apis/beacon/blocks/headers.yaml b/apis/beacon/blocks/headers.yaml
index f0568158..a4256b7c 100644
--- a/apis/beacon/blocks/headers.yaml
+++ b/apis/beacon/blocks/headers.yaml
@@ -29,6 +29,8 @@ get:
             title: GetBlockHeadersResponse
             type: object
             properties:
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 type: array
                 items:
diff --git a/apis/beacon/blocks/root.yaml b/apis/beacon/blocks/root.yaml
index c590786a..3da53125 100644
--- a/apis/beacon/blocks/root.yaml
+++ b/apis/beacon/blocks/root.yaml
@@ -17,6 +17,8 @@ get:
             type: object
             title: GetBlockRootResponse
             properties:
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 type: object
                 properties:
diff --git a/apis/beacon/states/committee.yaml b/apis/beacon/states/committee.yaml
index 30381c04..ed69c1c0 100644
--- a/apis/beacon/states/committee.yaml
+++ b/apis/beacon/states/committee.yaml
@@ -42,6 +42,8 @@ get:
             title: GetEpochCommitteesResponse
             type: object
             properties:
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 type: array
                 items:
diff --git a/apis/beacon/states/finality_checkpoints.yaml b/apis/beacon/states/finality_checkpoints.yaml
index 7a8f9b88..ec812d3f 100644
--- a/apis/beacon/states/finality_checkpoints.yaml
+++ b/apis/beacon/states/finality_checkpoints.yaml
@@ -19,6 +19,8 @@ get:
             title: GetStateFinalityCheckpointsResponse
             type: object
             properties:
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 type: object
                 properties:
diff --git a/apis/beacon/states/fork.yaml b/apis/beacon/states/fork.yaml
index 10f0f5a7..85be14f7 100644
--- a/apis/beacon/states/fork.yaml
+++ b/apis/beacon/states/fork.yaml
@@ -18,6 +18,8 @@ get:
             title: GetStateForkResponse
             type: object
             properties:
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 $ref: '../../../beacon-node-oapi.yaml#/components/schemas/Fork'
 
diff --git a/apis/beacon/states/root.yaml b/apis/beacon/states/root.yaml
index 80a6d320..4f8cf5c5 100644
--- a/apis/beacon/states/root.yaml
+++ b/apis/beacon/states/root.yaml
@@ -17,6 +17,8 @@ get:
             title: GetStateRootResponse
             type: object
             properties:
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 type: object
                 properties:
diff --git a/apis/beacon/states/sync_committees.yaml b/apis/beacon/states/sync_committees.yaml
index 31188b00..bff5c69e 100644
--- a/apis/beacon/states/sync_committees.yaml
+++ b/apis/beacon/states/sync_committees.yaml
@@ -26,6 +26,8 @@ get:
             title: GetEpochSyncCommitteesResponse
             type: object
             properties:
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 $ref: '../../../beacon-node-oapi.yaml#/components/schemas/Altair.SyncCommittee'
 
diff --git a/apis/beacon/states/validator.yaml b/apis/beacon/states/validator.yaml
index 8f4900ab..53621133 100644
--- a/apis/beacon/states/validator.yaml
+++ b/apis/beacon/states/validator.yaml
@@ -25,6 +25,8 @@ get:
             title: GetStateValidatorResponse
             type: object
             properties:
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 $ref: '../../../beacon-node-oapi.yaml#/components/schemas/ValidatorResponse'
     "400":
diff --git a/apis/beacon/states/validator_balances.yaml b/apis/beacon/states/validator_balances.yaml
index 88897408..8882a1f1 100644
--- a/apis/beacon/states/validator_balances.yaml
+++ b/apis/beacon/states/validator_balances.yaml
@@ -35,6 +35,8 @@ get:
             title: GetStateValidatorBalancesResponse
             type: object
             properties:
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 type: array
                 items:
diff --git a/apis/beacon/states/validators.yaml b/apis/beacon/states/validators.yaml
index 888dea9d..f86e6d6d 100644
--- a/apis/beacon/states/validators.yaml
+++ b/apis/beacon/states/validators.yaml
@@ -46,6 +46,8 @@ get:
             title: GetStateValidatorsResponse
             type: object
             properties:
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 type: array
                 items:
diff --git a/apis/debug/heads.v2.yaml b/apis/debug/heads.v2.yaml
new file mode 100644
index 00000000..90eb09e4
--- /dev/null
+++ b/apis/debug/heads.v2.yaml
@@ -0,0 +1,28 @@
+get:
+  operationId: getDebugChainHeadsV2
+  summary: Get fork choice leaves
+  description: Retrieves all possible chain heads (leaves of fork choice tree).
+  tags:
+    - Debug
+  responses:
+    "200":
+      description: Success
+      content:
+        application/json:
+          schema:
+            title: GetDebugChainHeadsResponse
+            type: object
+            properties:
+              data:
+                type: array
+                items:
+                  type: object
+                  properties:
+                    root:
+                      $ref: "../../beacon-node-oapi.yaml#/components/schemas/Root"
+                    slot:
+                      $ref: "../../beacon-node-oapi.yaml#/components/schemas/Uint64"
+                    execution_optimistic:
+                      $ref: "../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+    "500":
+      $ref: "../../beacon-node-oapi.yaml#/components/responses/InternalError"
diff --git a/apis/debug/heads.yaml b/apis/debug/heads.yaml
index f5f2a2cf..49719294 100644
--- a/apis/debug/heads.yaml
+++ b/apis/debug/heads.yaml
@@ -2,6 +2,7 @@ get:
   operationId: getDebugChainHeads
   summary: Get fork choice leaves
   description: Retrieves all possible chain heads (leaves of fork choice tree).
+  deprecated: true
   tags:
     - Debug
   responses:
diff --git a/apis/debug/state.v2.yaml b/apis/debug/state.v2.yaml
index c396bf5d..f1c22e3d 100644
--- a/apis/debug/state.v2.yaml
+++ b/apis/debug/state.v2.yaml
@@ -27,6 +27,8 @@ get:
                 type: string
                 enum: [ phase0, altair ]
                 example: "phase0"
+              execution_optimistic:
+                $ref: "../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 oneOf:
                  - $ref: '../../beacon-node-oapi.yaml#/components/schemas/BeaconState'
diff --git a/apis/eventstream/index.yaml b/apis/eventstream/index.yaml
index b0b0f748..fe6da831 100644
--- a/apis/eventstream/index.yaml
+++ b/apis/eventstream/index.yaml
@@ -42,11 +42,13 @@ get:
               description: The node has finished processing, resulting in a new head. previous_duty_dependent_root is `get_block_root_at_slot(state, compute_start_slot_at_epoch(epoch - 1) - 1)` and current_duty_dependent_root is `get_block_root_at_slot(state, compute_start_slot_at_epoch(epoch) - 1)`. Both dependent roots use the genesis block root in the case of underflow.
               value: |
                 event: head
+                execution_optimistic: false
                 data: {"slot":"10", "block":"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf", "state":"0x600e852a08c1200654ddf11025f1ceacb3c2e74bdd5c630cde0838b2591b69f9", "epoch_transition":false, "previous_duty_dependent_root":"0x5e0043f107cb57913498fbf2f99ff55e730bf1e151f02f221e977c91a90a0e91", "current_duty_dependent_root":"0x5e0043f107cb57913498fbf2f99ff55e730bf1e151f02f221e977c91a90a0e91"}
             block:
               description: The node has received a valid block (from P2P or API)
               value: |
                 event: block
+                execution_optimistic: false
                 data: {"slot":"10", "block":"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf"}
             attestation:
               description: The node has received a valid attestation (from P2P or API)
@@ -62,11 +64,13 @@ get:
               description: Finalized checkpoint has been updated
               value: |
                 event: finalized_checkpoint
+                execution_optimistic: false
                 data: {"block":"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf", "state":"0x600e852a08c1200654ddf11025f1ceacb3c2e74bdd5c630cde0838b2591b69f9", "epoch":"2" }
             chain_reorg:
               description: The node has reorganized its chain
               value: |
                 event: chain_reorg
+                execution_optimistic: false
                 data: {"slot":"200", "depth":"50", "old_head_block":"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf", "new_head_block":"0x76262e91970d375a19bfe8a867288d7b9cde43c8635f598d93d39d041706fc76", "old_head_state":"0x9a2fefd2fdb57f74993c7780ea5b9030d2897b615b89f808011ca5aebed54eaf", "new_head_state":"0x600e852a08c1200654ddf11025f1ceacb3c2e74bdd5c630cde0838b2591b69f9", "epoch":"2"}
             contribution_and_proof:
               description: The node has received a valid sync committee SignedContributionAndProof (from P2P or API)
diff --git a/apis/validator/block.v2.yaml b/apis/validator/block.v2.yaml
index f0a4fb53..3dc78567 100644
--- a/apis/validator/block.v2.yaml
+++ b/apis/validator/block.v2.yaml
@@ -59,4 +59,4 @@ get:
     "500":
       $ref: '../../beacon-node-oapi.yaml#/components/responses/InternalError'
     "503":
-      $ref: '../../beacon-node-oapi.yaml#/components/responses/CurrentlySyncing'
\ No newline at end of file
+      $ref: '../../beacon-node-oapi.yaml#/components/responses/CurrentlySyncing'
diff --git a/apis/validator/duties/attester.yaml b/apis/validator/duties/attester.yaml
index 9a783513..473e73fa 100644
--- a/apis/validator/duties/attester.yaml
+++ b/apis/validator/duties/attester.yaml
@@ -50,6 +50,8 @@ post:
             properties:
               dependent_root:
                 $ref: "../../../beacon-node-oapi.yaml#/components/schemas/DependentRoot"
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 type: array
                 items:
diff --git a/apis/validator/duties/proposer.yaml b/apis/validator/duties/proposer.yaml
index 1ce1b834..4491bb7e 100644
--- a/apis/validator/duties/proposer.yaml
+++ b/apis/validator/duties/proposer.yaml
@@ -34,6 +34,8 @@ get:
             properties:
               dependent_root:
                 $ref: "../../../beacon-node-oapi.yaml#/components/schemas/DependentRoot"
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 type: array
                 items:
diff --git a/apis/validator/duties/sync.yaml b/apis/validator/duties/sync.yaml
index b578786d..aa014fb7 100644
--- a/apis/validator/duties/sync.yaml
+++ b/apis/validator/duties/sync.yaml
@@ -32,6 +32,8 @@ post:
             title: GetSyncCommitteeDutiesResponse
             type: object
             properties:
+              execution_optimistic:
+                $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
               data:
                 type: array
                 items:
diff --git a/beacon-node-oapi.yaml b/beacon-node-oapi.yaml
index 8451193b..09f693b2 100644
--- a/beacon-node-oapi.yaml
+++ b/beacon-node-oapi.yaml
@@ -95,6 +95,8 @@ paths:
     $ref: './apis/debug/state.v2.yaml'
   /eth/v1/debug/beacon/heads:
     $ref: './apis/debug/heads.yaml'
+  /eth/v2/debug/beacon/heads:
+    $ref: './apis/debug/heads.v2.yaml'
 
   /eth/v1/node/identity:
     $ref: "./apis/node/identity.yaml"
@@ -209,6 +211,8 @@ components:
       $ref: './types/primitive.yaml#/ForkVersion'
     DependentRoot:
       $ref: './types/primitive.yaml#/DependentRoot'
+    ExecutionOptimistic:
+      $ref: './types/primitive.yaml#/ExecutionOptimistic'
     Root:
       $ref: './types/primitive.yaml#/Root'
     Hex:
diff --git a/types/primitive.yaml b/types/primitive.yaml
index 2943b2a9..7d7d92c9 100644
--- a/types/primitive.yaml
+++ b/types/primitive.yaml
@@ -33,6 +33,12 @@ DependentRoot:
     - $ref: "./primitive.yaml#/Root"
     - description: "The block root that this response is dependent on."
 
+ExecutionOptimistic:
+  allOf:
+    - type: boolean
+    - example: false
+    - description: "True if the response references an unverified execution payload. Optimistic information may be invalidated at a later time. If the field is not present, assume the False value."
+
 Root:
   type: string
   example: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"