feat: update spec to use v4 payload methods for isthmus (#525)

* feat: update spec to use v4 payload methods for isthmus

* Lint and specify v3 or v2 could be used

* Fix lint

* Fix toc name

* Fix toc

specs/protocol/derivation.md

@@ -748,19 +748,22 @@ To interact with the engine, the [execution engine API][exec-engine] is used, wi
 - `engine_newPayload`
   - [`engine_newPayloadV2`] — executes a Bedrock/Canyon/Delta execution payload to create a block.
   - [`engine_newPayloadV3`] — executes an Ecotone execution payload to create a block.
+  - [`engine_newPayloadV4`] - executes an Isthmus execution payload to create a block.
 
-The current version of `op-node` uses the `v3` Engine API RPC methods as well as `engine_newPayloadV2`, due to
-`engine_newPayloadV3` only supporting Ecotone execution payloads. Both `engine_forkchoiceUpdatedV3` and
-`engine_getPayloadV3` are backwards compatible with Bedrock, Canyon & Delta payloads.
+The current version of `op-node` uses the `v4` Engine API RPC methods as well as `engine_newPayloadV3` and
+`engine_newPayloadV2`, due to `engine_newPayloadV4` only supporting Isthmus execution payloads. Both
+`engine_forkchoiceUpdatedV4` and `engine_getPayloadV4` are backwards compatible with Ecotone, Bedrock,
+Canyon & Delta payloads.
 
-Prior versions of `op-node` used `v2` and `v1` methods.
+Prior versions of `op-node` used `v3`, `v2` and `v1` methods.
 
 [`engine_forkchoiceUpdatedV2`]: exec-engine.md#engine_forkchoiceupdatedv2
 [`engine_forkchoiceUpdatedV3`]: exec-engine.md#engine_forkchoiceupdatedv3
 [`engine_getPayloadV2`]: exec-engine.md#engine_getpayloadv2
 [`engine_getPayloadV3`]: exec-engine.md#engine_getpayloadv3
 [`engine_newPayloadV2`]: exec-engine.md#engine_newpayloadv2
 [`engine_newPayloadV3`]: exec-engine.md#engine_newpayloadv3
+[`engine_newPayloadV4`]: exec-engine.md#engine_newpayloadv4
 
 The execution payload is an object of type [`ExecutionPayloadV3`][eth-payload].
 
@@ -887,6 +890,8 @@ The payload is then processed with a sequence of:
 - Ecotone Payloads
   - `engine_newPayloadV3`: process the payload. It does not become canonical yet.
   - `engine_forkchoiceUpdatedV3`: make the payload the canonical unsafe L2 head, and keep the safe/finalized L2 heads.
+- Isthmus Payloads
+  - `engine_newPayloadV4`: process the payload. It does not become canonical yet.
 
 Engine API Error handling:
 

specs/protocol/exec-engine.md

@@ -21,9 +21,11 @@
     - [Extended PayloadAttributesV3](#extended-payloadattributesv3)
   - [`engine_newPayloadV2`](#engine_newpayloadv2)
   - [`engine_newPayloadV3`](#engine_newpayloadv3)
+  - [`engine_newPayloadV4`](#engine_newpayloadv4)
   - [`engine_getPayloadV2`](#engine_getpayloadv2)
   - [`engine_getPayloadV3`](#engine_getpayloadv3)
     - [Extended Response](#extended-response)
+  - [`engine_getPayloadV4`](#engine_getpayloadv4)
   - [`engine_signalSuperchainV1`](#engine_signalsuperchainv1)
 - [Networking](#networking)
 - [Sync](#sync)
@@ -299,6 +301,16 @@ The additional parameters should be set as follows:
 - `expectedBlobVersionedHashes` MUST be an empty array.
 - `parentBeaconBlockRoot` MUST be the parent beacon block root from the L1 origin block of the L2 block.
 
+### `engine_newPayloadV4`
+
+[`engine_newPayloadV4`][engine_newPayloadV4] applies an Isthmus L2 block to the engine state. There are no
+modifications to this API.
+`engine_newPayloadV4` **must only be called with Isthmus payload.**
+
+The additional parameters should be set as follows:
+
+- `executionRequests` MUST be an empty array.
+
 ### `engine_getPayloadV2`
 
 No modifications to [`engine_getPayloadV2`][engine_getPayloadV2].
@@ -328,6 +340,12 @@ The [response][GetPayloadV3Response] is extended to:
 
 In Ecotone it MUST be set to the parentBeaconBlockRoot from the L1 Origin block of the L2 block.
 
+### `engine_getPayloadV4`
+
+[`engine_getPayloadV4`][engine_getPayloadV4] retrieves a payload by ID, prepared by `engine_forkchoiceUpdatedV3`
+when called with `payloadAttributes`.
+`engine_getPayloadV4` **must only be called with Isthmus payload.**
+
 ### `engine_signalSuperchainV1`
 
 Optional extension to the Engine API. Signals superchain information to the Engine:

specs/protocol/isthmus/exec-engine.md

@@ -20,7 +20,7 @@
 - [Block Body Withdrawals List](#block-body-withdrawals-list)
 - [Engine API Updates](#engine-api-updates)
   - [Update to `ExecutableData`](#update-to-executabledata)
-  - [`engine_newPayloadV3` API](#engine_newpayloadv3-api)
+  - [`engine_newPayloadV4` API](#engine_newpayloadv4-api)
 
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
 
@@ -137,7 +137,7 @@ Withdrawals list in the block body is encoded as an empty RLP list.
 
 `ExecutableData` will contain an extra field for `withdrawalsRoot` after Isthmus hard fork.
 
-### `engine_newPayloadV3` API
+### `engine_newPayloadV4` API
 
-Post Isthmus, `engine_newPayloadV3` will be used with the additional `ExecutionPayload` attribute. This attribute
+Post Isthmus, `engine_newPayloadV4` will be used with the additional `ExecutionPayload` attribute. This attribute
 is omitted prior to Isthmus.