Add finalized flag to chain data requests

Whether or not a request pertains to the finalized section of the chain
(per the view of the client fork choice) is somewhat cumbersome to
discover.

This PR adds a boolean that allows clients to distinguish a response
that has been finalized and thus is unlikely to change from one that may
still change over time (specially when using slot-based requests).

A flag like this can also be used for the purpose of verifying that a
checkpoint root indeed is part of chain history and is likely to remain
as such, as discussed in
ethereum#226

apis/beacon/blocks/attestations.yaml

@@ -9,7 +9,7 @@ get:
  in: path
  required: true
  $ref: '../../../beacon-node-oapi.yaml#/components/parameters/BlockId'
- 
+
  responses:
  "200":
  description: Success
@@ -21,6 +21,8 @@ get:
  properties:
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  type: array
  items:

apis/beacon/blocks/blinded_block.yaml

@@ -29,6 +29,8 @@ get:
  example: "phase0"
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  oneOf:
  - $ref: "../../../beacon-node-oapi.yaml#/components/schemas/SignedBeaconBlock"

apis/beacon/blocks/block.v2.yaml

@@ -29,14 +29,16 @@ get:
  example: "phase0"
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  oneOf:
  - $ref: "../../../beacon-node-oapi.yaml#/components/schemas/SignedBeaconBlock"
  - $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Altair.SignedBeaconBlock"
  - $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Bellatrix.SignedBeaconBlock"
  application/octet-stream:
  schema:
- 
+
  description: "SSZ serialized block bytes. Use Accept header to choose this response type"
  "400":
  description: "The block ID supplied could not be parsed"

apis/beacon/blocks/header.yaml

@@ -20,6 +20,8 @@ get:
  properties:
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  type: object
  properties:

apis/beacon/blocks/headers.yaml

@@ -19,7 +19,7 @@ get:
  allOf:
  - $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Root"
  - example: ""
- 
+
  responses:
  "200":
  description: Success
@@ -31,6 +31,8 @@ get:
  properties:
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  type: array
  items:

apis/beacon/blocks/root.yaml

@@ -26,6 +26,8 @@ get:
  properties:
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  type: object
  properties:

apis/beacon/states/committee.yaml

@@ -44,6 +44,8 @@ get:
  properties:
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  type: array
  items:

apis/beacon/states/finality_checkpoints.yaml

@@ -21,6 +21,8 @@ get:
  properties:
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  type: object
  properties:

apis/beacon/states/fork.yaml

@@ -20,6 +20,8 @@ get:
  properties:
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  $ref: '../../../beacon-node-oapi.yaml#/components/schemas/Fork'
 

apis/beacon/states/randao.yaml

@@ -35,6 +35,8 @@ get:
  properties:
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  type: object
  properties:

apis/beacon/states/root.yaml

@@ -19,6 +19,8 @@ get:
  properties:
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  type: object
  properties:

apis/beacon/states/sync_committees.yaml

@@ -28,6 +28,8 @@ get:
  properties:
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  $ref: '../../../beacon-node-oapi.yaml#/components/schemas/Altair.SyncCommittee'
 

apis/beacon/states/validator.yaml

@@ -27,6 +27,8 @@ get:
  properties:
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  $ref: '../../../beacon-node-oapi.yaml#/components/schemas/ValidatorResponse'
  "400":

apis/beacon/states/validator_balances.yaml

@@ -37,6 +37,8 @@ get:
  properties:
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  type: array
  items:

apis/beacon/states/validators.yaml

@@ -48,6 +48,8 @@ get:
  properties:
  execution_optimistic:
  $ref: "../../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  type: array
  items:

apis/debug/state.v2.yaml

@@ -29,6 +29,8 @@ get:
  example: "phase0"
  execution_optimistic:
  $ref: "../../beacon-node-oapi.yaml#/components/schemas/ExecutionOptimistic"
+ finalized:
+ $ref: "../../../beacon-node-oapi.yaml#/components/schemas/Finalized"
  data:
  oneOf:
  - $ref: '../../beacon-node-oapi.yaml#/components/schemas/BeaconState'

apis/validator/duties/attester.yaml

@@ -18,7 +18,7 @@ post:
 
  - event.block otherwise
 
- 
+
  The dependent_root value is `get_block_root_at_slot(state, compute_start_slot_at_epoch(epoch - 1) - 1)`
  or the genesis block root in the case of underflow."
  parameters:

beacon-node-oapi.yaml

@@ -237,6 +237,8 @@ components:
  $ref: './types/primitive.yaml#/DependentRoot'
  ExecutionOptimistic:
  $ref: './types/primitive.yaml#/ExecutionOptimistic'
+ Finalized:
+ $ref: './types/primitive.yaml#/Finalized'
  Root:
  $ref: './types/primitive.yaml#/Root'
  Hex:

types/primitive.yaml

@@ -45,6 +45,12 @@ ExecutionOptimistic:
  - 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."
 
+Finalized:
+ allOf:
+ - type: boolean
+ - example: false
+ - description: "True if the response references the finalized history of the chain, as determined by fork choice. If the field is not present, additional calls are necessary to compare the epoch of the requested information with the finalized checkpoint."
+
 Root:
  type: string
  format: hex