feat(spec-specs, spec-tests): add EIP-7843 SLOTNUM opcode

packages/testing/src/execution_testing/cli/pytest_commands/plugins/consume/simulators/single_test_client.py

@@ -34,6 +34,9 @@ def client_genesis(fixture: BlockchainFixtureCommon) -> dict:
     alloc = to_json(fixture.pre)
     # NOTE: nethermind requires account keys without '0x' prefix
     genesis["alloc"] = {k.replace("0x", ""): v for k, v in alloc.items()}
+    # NOTE: geth expects slotNumber as plain integer, not hex string
+    if "slotNumber" in genesis:
+        genesis["slotNumber"] = int(genesis["slotNumber"], 16)
     return genesis
 
 

packages/testing/src/execution_testing/cli/pytest_commands/plugins/execute/rpc/chain_builder_eth_rpc.py

@@ -156,6 +156,9 @@ def _payload_attributes(
                 if next_fork.engine_payload_attribute_max_blobs_per_block()
                 else None
             ),
+            slot_number=(
+                0 if next_fork.engine_payload_attribute_slot_number() else None
+            ),
         )
 
     def _finalize_payload(

packages/testing/src/execution_testing/fixtures/blockchain.py

@@ -211,6 +211,10 @@ class FixtureHeader(CamelModel):
     block_access_list_hash: (
         Annotated[Hash, HeaderForkRequirement("bal_hash")] | None
     ) = Field(None, alias="blockAccessListHash")
+    slot_number: (
+        Annotated[ZeroPaddedHexNumber, HeaderForkRequirement("slot_number")]
+        | None
+    ) = Field(None)
 
     fork: Fork | None = Field(None, exclude=True)
 
@@ -349,7 +353,7 @@ def get_default_from_annotation(
     def genesis(cls, fork: Fork, env: Environment, state_root: Hash) -> Self:
         """Get the genesis header for the given fork."""
         environment_values = env.model_dump(
-            exclude_none=True, exclude={"withdrawals"}
+            exclude_none=True, exclude={"withdrawals", "slot_number"}
         )
         if env.withdrawals is not None:
             environment_values["withdrawals_root"] = Withdrawal.list_root(
@@ -366,6 +370,7 @@ def genesis(cls, fork: Fork, env: Environment, state_root: Hash) -> Self:
                 if fork.header_bal_hash_required()
                 else None
             ),
+            "slot_number": 0 if fork.header_slot_number_required() else None,
             "fork": fork,
         }
         return cls(**environment_values, **extras)
@@ -406,6 +411,7 @@ class FixtureExecutionPayload(CamelModel):
     block_access_list: Bytes | None = Field(
         None, description="RLP-serialized EIP-7928 Block Access List"
     )
+    slot_number: HexNumber | None = Field(None)
 
     @classmethod
     def from_fixture_header(

packages/testing/src/execution_testing/forks/base_fork.py

@@ -436,6 +436,12 @@ def empty_block_bal_item_count(cls) -> int:
         """
         pass
 
+    @classmethod
+    @abstractmethod
+    def header_slot_number_required(cls) -> bool:
+        """Return true if the header must contain slot number (EIP-7843)."""
+        pass
+
     # Gas related abstract methods
 
     @classmethod
@@ -881,6 +887,14 @@ def engine_payload_attribute_max_blobs_per_block(cls) -> bool:
         """
         pass
 
+    @classmethod
+    @abstractmethod
+    def engine_payload_attribute_slot_number(cls) -> bool:
+        """
+        Return true if the payload attributes include the slot number.
+        """
+        pass
+
     # Engine API method versions
     @classmethod
     def engine_new_payload_version(cls) -> Optional[int]:

packages/testing/src/execution_testing/forks/forks/eips/amsterdam/eip_7843.py

@@ -0,0 +1,54 @@
+"""
+EIP-7843: SLOTNUM opcode.
+
+Opcode to get the current slot number.
+
+https://eips.ethereum.org/EIPS/eip-7843
+"""
+
+from typing import Callable, Dict, List
+
+from execution_testing.vm import (
+    OpcodeBase,
+    Opcodes,
+)
+
+from ....base_fork import BaseFork
+
+
+class EIP7843(
+    BaseFork,
+    # Engine API method version bumps
+    # New field `slotNumber` in ExecutionPayload
+    engine_new_payload_version_bump=True,
+    engine_get_payload_version_bump=True,
+    engine_forkchoice_updated_version_bump=True,
+):
+    """EIP-7843 class."""
+
+    @classmethod
+    def header_slot_number_required(cls) -> bool:
+        """Slot number in header required."""
+        return True
+
+    @classmethod
+    def engine_payload_attribute_slot_number(cls) -> bool:
+        """Payload attributes include the slot number."""
+        return True
+
+    @classmethod
+    def opcode_gas_map(
+        cls,
+    ) -> Dict[OpcodeBase, int | Callable[[OpcodeBase], int]]:
+        """Add SLOTNUM opcode gas cost."""
+        gas_costs = cls.gas_costs()
+        base_map = super(EIP7843, cls).opcode_gas_map()
+        return {
+            **base_map,
+            Opcodes.SLOTNUM: gas_costs.BASE,
+        }
+
+    @classmethod
+    def valid_opcodes(cls) -> List[Opcodes]:
+        """Add SLOTNUM opcode."""
+        return [Opcodes.SLOTNUM] + super(EIP7843, cls).valid_opcodes()

packages/testing/src/execution_testing/forks/forks/forks.py

@@ -925,6 +925,11 @@ def header_beacon_root_required(cls) -> bool:
         """At genesis, header must not contain parent beacon block root."""
         return False
 
+    @classmethod
+    def header_slot_number_required(cls) -> bool:
+        """At genesis, header must not contain slot number (EIP-7843)."""
+        return False
+
     @classmethod
     def engine_new_payload_blob_hashes(cls) -> bool:
         """At genesis, payloads do not have blob hashes."""
@@ -965,6 +970,13 @@ def engine_payload_attribute_max_blobs_per_block(cls) -> bool:
         """
         return False
 
+    @classmethod
+    def engine_payload_attribute_slot_number(cls) -> bool:
+        """
+        At genesis, payload attributes do not include the slot number.
+        """
+        return False
+
     @classmethod
     def get_reward(cls) -> int:
         """

packages/testing/src/execution_testing/rpc/rpc_types.py

@@ -212,6 +212,7 @@ class PayloadAttributes(CamelModel):
     parent_beacon_block_root: Hash | None = None
     target_blobs_per_block: HexNumber | None = None
     max_blobs_per_block: HexNumber | None = None
+    slot_number: HexNumber | None = None
 
 
 class BlobsBundle(CamelModel):

packages/testing/src/execution_testing/specs/blockchain.py

@@ -30,6 +30,7 @@
     HeaderNonce,
     HexNumber,
     Number,
+    ZeroPaddedHexNumber,
 )
 from execution_testing.client_clis import (
     BlockExceptionWithMessage,
@@ -165,6 +166,7 @@ class Header(CamelModel):
     parent_beacon_block_root: Removable | Hash | None = None
     requests_hash: Removable | Hash | None = None
     block_access_list_hash: Removable | Hash | None = None
+    slot_number: Removable | HexNumber | None = None
 
     REMOVE_FIELD: ClassVar[Removable] = Removable()
     """
@@ -351,6 +353,8 @@ def set_environment(self, env: Environment) -> Environment:
             and self.block_access_list is not None
         ):
             new_env_values["block_access_list"] = self.block_access_list
+        if not isinstance(self.slot_number, Removable):
+            new_env_values["slot_number"] = self.slot_number
         """
         These values are required, but they depend on the previous environment,
         so they can be calculated here.
@@ -672,19 +676,30 @@ def generate_block_data(
             if (blob_gas_per_blob := fork.blob_gas_per_blob()) > 0:
                 blob_gas_used = blob_gas_per_blob * count_blobs(txs)
 
+        # Prepare slot_number for header initialization
+        slot_number_value: ZeroPaddedHexNumber | None = None
+        if fork.header_slot_number_required():
+            slot_number_value = ZeroPaddedHexNumber(
+                int(env.slot_number) if env.slot_number is not None else 0
+            )
+
         header = FixtureHeader(
             **(
                 transition_tool_output.result.model_dump(
                     exclude_none=True,
                     exclude={"blob_gas_used", "transactions_trie"},
                 )
-                | env.model_dump(exclude_none=True, exclude={"blob_gas_used"})
+                | env.model_dump(
+                    exclude_none=True,
+                    exclude={"blob_gas_used", "slot_number"},
+                )
             ),
             blob_gas_used=blob_gas_used,
             transactions_trie=Transaction.list_root(txs),
-            extra_data=block.extra_data
-            if block.extra_data is not None
-            else b"",
+            extra_data=(
+                block.extra_data if block.extra_data is not None else b""
+            ),
+            slot_number=slot_number_value,
             fork=fork,
         )
 
@@ -777,7 +792,8 @@ def generate_block_data(
                 t8n_bal
             )
             if bal != t8n_bal:
-                # If the BAL was modified, update the header hash
+                # If the BAL was modified and the fork requires it, update the
+                # header hash
                 header.block_access_list_hash = Hash(bal.rlp.keccak256())
 
         built_block = BuiltBlock(

packages/testing/src/execution_testing/specs/state.py

@@ -318,6 +318,7 @@ def _generate_blockchain_blocks(self) -> List[Block]:
             "extra_data": self.env.extra_data,
             "withdrawals": self.env.withdrawals,
             "parent_beacon_block_root": self.env.parent_beacon_block_root,
+            "slot_number": self.env.slot_number,
             "txs": [self.tx],
             "ommers": [],
             "header_verify": self.blockchain_test_header_verify,

packages/testing/src/execution_testing/specs/static_state/environment.py

@@ -33,6 +33,7 @@ class EnvironmentInStateTestFiller(BaseModel):
     current_excess_blob_gas: ValueInFiller | None = Field(
         None, alias="currentExcessBlobGas"
     )
+    current_slot_number: ValueInFiller | None = Field(None, alias="slotNumber")
 
     model_config = ConfigDict(extra="forbid")
 
@@ -72,4 +73,6 @@ def get_environment(self, tags: TagDict) -> Environment:
             kwargs["base_fee_per_gas"] = self.current_base_fee
         if self.current_excess_blob_gas is not None:
             kwargs["excess_blob_gas"] = self.current_excess_blob_gas
+        if self.current_slot_number is not None:
+            kwargs["slot_number"] = self.current_slot_number
         return Environment(**kwargs)

packages/testing/src/execution_testing/test_types/block_types.py

@@ -101,6 +101,7 @@ class EnvironmentGeneric(CamelModel, Generic[NumberBoundTypeVar]):
     excess_blob_gas: NumberBoundTypeVar | None = Field(
         None, alias="currentExcessBlobGas"
     )
+    slot_number: NumberBoundTypeVar | None = Field(None, alias="slotNumber")
 
     parent_difficulty: NumberBoundTypeVar | None = Field(None)
     parent_timestamp: NumberBoundTypeVar | None = Field(None)
@@ -200,6 +201,9 @@ def set_fork_requirements(self, fork: Fork) -> "Environment":
         ):
             updated_values["parent_beacon_block_root"] = 0
 
+        if fork.header_slot_number_required() and self.slot_number is None:
+            updated_values["slot_number"] = 0
+
         return self.copy(**updated_values)
 
     def __hash__(self) -> int:

packages/testing/src/execution_testing/vm/opcodes.py

@@ -2225,6 +2225,36 @@ class Opcodes(Opcode, Enum):
     Source: [EIP-7516](https://eips.ethereum.org/EIPS/eip-7516)
     """
 
+    SLOTNUM = Opcode(0x4B, popped_stack_items=0, pushed_stack_items=1)
+    """
+    SLOTNUM() = slotNumber
+    ----
+
+    Description
+    ----
+    Returns the current slot number as provided by the consensus layer.
+    The slot number is passed from the consensus layer to the execution
+    layer through the engine API.
+
+    Inputs
+    ----
+    - None
+
+    Outputs
+    ----
+    - slotNumber: current slot number (uint64)
+
+    Fork
+    ----
+    Amsterdam
+
+    Gas
+    ----
+    2
+
+    Source: [EIP-7843](https://eips.ethereum.org/EIPS/eip-7843)
+    """
+
     POP = Opcode(0x50, popped_stack_items=1)
     """
     POP()

src/ethereum/forks/amsterdam/blocks.py

@@ -114,7 +114,7 @@ class Header:
     [`keccak256`]: ref:ethereum.crypto.hash.keccak256
     [changes]: ref:ethereum.state.State.compute_state_root_and_trie_changes
     [Trie]: ref:ethereum.merkle_patricia_trie.Trie
-    """  # noqa: E501
+    """
 
     transactions_root: Root
     """
@@ -258,6 +258,14 @@ class Header:
     [cbalh]: ref:ethereum.forks.amsterdam.block_access_lists.hash_block_access_list
     """  # noqa: E501
 
+    slot_number: U64
+    """
+    The slot number of this block as provided by the consensus layer.
+    Introduced in [EIP-7843].
+
+    [EIP-7843]: https://eips.ethereum.org/EIPS/eip-7843
+    """
+
 
 @slotted_freezable
 @dataclass

src/ethereum/forks/amsterdam/fork.py

@@ -314,6 +314,7 @@ def execute_block(
         excess_blob_gas=block.header.excess_blob_gas,
         parent_beacon_block_root=block.header.parent_beacon_block_root,
         block_access_list_builder=BlockAccessListBuilder(),
+        slot_number=block.header.slot_number,
     )
 
     block_output = apply_body(

src/ethereum/forks/amsterdam/vm/__init__.py

@@ -57,6 +57,7 @@ class BlockEnvironment:
     excess_blob_gas: U64
     parent_beacon_block_root: Hash32
     block_access_list_builder: BlockAccessListBuilder
+    slot_number: U64
 
 
 @dataclass

src/ethereum/forks/amsterdam/vm/gas.py

@@ -165,6 +165,7 @@ class GasCosts:
     OPCODE_CHAINID = BASE
     OPCODE_BASEFEE = BASE
     OPCODE_BLOBBASEFEE = BASE
+    OPCODE_SLOTNUM = BASE
     OPCODE_BLOBHASH = Uint(3)
     OPCODE_PUSH = VERY_LOW
     OPCODE_PUSH0 = BASE

src/ethereum/forks/amsterdam/vm/instructions/__init__.py

@@ -99,6 +99,7 @@ class Ops(enum.Enum):
     BASEFEE = 0x48
     BLOBHASH = 0x49
     BLOBBASEFEE = 0x4A
+    SLOTNUM = 0x4B
 
     # Control Flow Ops
     STOP = 0x00
@@ -251,6 +252,7 @@ class Ops(enum.Enum):
     Ops.PREVRANDAO: block_instructions.prev_randao,
     Ops.GASLIMIT: block_instructions.gas_limit,
     Ops.CHAINID: block_instructions.chain_id,
+    Ops.SLOTNUM: block_instructions.slot_number,
     Ops.MLOAD: memory_instructions.mload,
     Ops.MSTORE: memory_instructions.mstore,
     Ops.MSTORE8: memory_instructions.mstore8,