EIP-7742: Add target_blob_count to block header (#7808)

Signed-off-by: Simon Dudley <simon.dudley@consensys.net>

acceptance-tests/dsl/src/main/java/org/hyperledger/besu/tests/acceptance/dsl/BlockUtils.java

@@ -58,6 +58,7 @@ public class BlockUtils {
         null,
         null,
         null,
+        null,
         blockHeaderFunctions);
   }
 }

acceptance-tests/tests/src/test/java/org/hyperledger/besu/tests/acceptance/jsonrpc/ExecutionEnginePragueAcceptanceTest.java

@@ -20,8 +20,11 @@ import java.util.stream.Stream;
 
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.params.provider.Arguments;
 
+// TODO SLD
+@Disabled("TODO SLD - Enable when Prague spec is finalized")
 public class ExecutionEnginePragueAcceptanceTest extends AbstractJsonRpcTest {
   private static final String GENESIS_FILE = "/jsonrpc/engine/prague/genesis.json";
   private static final String TEST_CASE_PATH = "/jsonrpc/engine/prague/test-cases/";

besu/src/test/java/org/hyperledger/besu/controller/AbstractBftBesuControllerBuilderTest.java

@@ -193,6 +193,7 @@ public abstract class AbstractBftBesuControllerBuilderTest {
             null,
             null,
             null,
+            null,
             getBlockHeaderFunctions());
     final Block block1 = new Block(header1, BlockBody.empty());
 

besu/src/test/java/org/hyperledger/besu/controller/CliqueBesuControllerBuilderTest.java

@@ -222,6 +222,7 @@ public class CliqueBesuControllerBuilderTest {
             null,
             null,
             null,
+            null,
             new CliqueBlockHeaderFunctions());
     final Block block1 = new Block(header1, BlockBody.empty());
 

besu/src/test/java/org/hyperledger/besu/services/BesuEventsImplTest.java

@@ -219,7 +219,7 @@ public class BesuEventsImplTest {
         mock(EthPeer.class),
         new org.hyperledger.besu.ethereum.core.BlockHeader(
             null, null, null, null, null, null, null, null, 1, 1, 1, 1, null, null, null, 1, null,
-            null, null, null, null, null));
+            null, null, null, null, null, null));
   }
 
   private void clearSyncTarget() {

config/src/main/java/org/hyperledger/besu/config/GenesisConfigFile.java

@@ -265,6 +265,17 @@ public class GenesisConfigFile {
         "0x0000000000000000000000000000000000000000000000000000000000000000");
   }
 
+  /**
+   * Gets target blob count.
+   *
+   * @return the target blob count
+   */
+  public Optional<String> getTargetBlobCount() {
+    // TODO SLD EIP-7742 not sure if we should use a default value here or enforce any
+    // "pragueAtGenesis" genesis file (used in devnets) to have this value
+    return JsonUtil.getValueAsString(genesisRoot, "targetblobcount");
+  }
+
   /**
    * Gets coinbase.
    *

ethereum/api/src/integration-test/java/org/hyperledger/besu/ethereum/api/jsonrpc/JsonRpcResponseKey.java

@@ -38,5 +38,6 @@ public enum JsonRpcResponseKey {
   TRANSACTION_ROOT,
   BASEFEE,
   WITHDRAWALS_ROOT,
-  REQUESTS_HASH
+  REQUESTS_HASH,
+  TARGET_BLOB_COUNT
 }

ethereum/api/src/integration-test/java/org/hyperledger/besu/ethereum/api/jsonrpc/JsonRpcResponseUtils.java

@@ -63,6 +63,7 @@ import java.util.Optional;
 import com.fasterxml.jackson.databind.JsonNode;
 import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.units.bigints.UInt256;
+import org.apache.tuweni.units.bigints.UInt64;
 
 public class JsonRpcResponseUtils {
 
@@ -106,6 +107,10 @@ public class JsonRpcResponseUtils {
         values.containsKey(WITHDRAWALS_ROOT) ? hash(values.get(WITHDRAWALS_ROOT)) : null;
     final Hash requestsHash =
         values.containsKey(REQUESTS_HASH) ? hash(values.get(REQUESTS_HASH)) : null;
+    final UInt64 targetBlobCount =
+        values.containsKey(JsonRpcResponseKey.TARGET_BLOB_COUNT)
+            ? UInt64.fromHexString(values.get(JsonRpcResponseKey.TARGET_BLOB_COUNT))
+            : null;
     final List<JsonNode> ommers = new ArrayList<>();
 
     final BlockHeader header =
@@ -131,6 +136,7 @@ public class JsonRpcResponseUtils {
             null, // ToDo 4844: set with the value of excess_blob_gas field
             null, // TODO 4788: set with the value of the parent beacon block root field
             requestsHash,
+            targetBlobCount,
             blockHeaderFunctions);
 
     return new JsonRpcSuccessResponse(

ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/AbstractEngineNewPayload.java

@@ -279,6 +279,7 @@ public abstract class AbstractEngineNewPayload extends ExecutionEngineJsonRpcMet
                 : BlobGas.fromHexString(blockParam.getExcessBlobGas()),
             maybeParentBeaconBlockRoot.orElse(null),
             maybeRequests.map(BodyValidation::requestsHash).orElse(null),
+            null, // TODO SLD EIP-7742 wiring in future PR
             headerFunctions);
 
     // ensure the block hash matches the blockParam hash

ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/results/BlockResult.java

@@ -88,6 +88,7 @@ public class BlockResult implements JsonRpcResult {
   private final String blobGasUsed;
   private final String excessBlobGas;
   private final String parentBeaconBlockRoot;
+  private final String targetBlobCount;
 
   public BlockResult(
       final BlockHeader header,
@@ -138,6 +139,7 @@ public class BlockResult implements JsonRpcResult {
     this.excessBlobGas = header.getExcessBlobGas().map(Quantity::create).orElse(null);
     this.parentBeaconBlockRoot =
         header.getParentBeaconBlockRoot().map(Bytes32::toHexString).orElse(null);
+    this.targetBlobCount = header.getTargetBlobCount().map(Quantity::create).orElse(null);
   }
 
   @JsonGetter(value = "number")
@@ -275,4 +277,9 @@ public class BlockResult implements JsonRpcResult {
   public String getParentBeaconBlockRoot() {
     return parentBeaconBlockRoot;
   }
+
+  @JsonGetter(value = "targetBlobCount")
+  public String getTargetBlobCount() {
+    return targetBlobCount;
+  }
 }

ethereum/api/src/test/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/EthGasPriceTest.java

@@ -372,6 +372,7 @@ public class EthGasPriceTest {
             null,
             null,
             null,
+            null,
             null),
         new BlockBody(
             IntStream.range(0, txsNum)

ethereum/api/src/test/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/EthMaxPriorityFeePerGasTest.java

@@ -207,6 +207,7 @@ public class EthMaxPriorityFeePerGasTest {
             null,
             null,
             null,
+            null,
             null),
         new BlockBody(
             IntStream.range(0, txsNum)

ethereum/api/src/test/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/engine/EngineExchangeTransitionConfigurationTest.java

@@ -254,6 +254,7 @@ public class EngineExchangeTransitionConfigurationTest {
         null,
         null,
         null,
+        null,
         new BlockHeaderFunctions() {
           @Override
           public Hash hash(final BlockHeader header) {

ethereum/api/src/test/java/org/hyperledger/besu/ethereum/api/query/BlockchainQueriesLogCacheTest.java

@@ -120,6 +120,7 @@ public class BlockchainQueriesLogCacheTest {
             null,
             null,
             null,
+            null,
             new MainnetBlockHeaderFunctions());
     testHash = fakeHeader.getHash();
     final BlockBody fakeBody = new BlockBody(Collections.emptyList(), Collections.emptyList());

ethereum/api/src/test/java/org/hyperledger/besu/ethereum/api/query/cache/TransactionLogBloomCacherTest.java

@@ -108,6 +108,7 @@ public class TransactionLogBloomCacherTest {
             null,
             null,
             null,
+            null,
             new MainnetBlockHeaderFunctions());
     testHash = fakeHeader.getHash();
     when(blockchain.getBlockHeader(anyLong())).thenReturn(Optional.of(fakeHeader));
@@ -283,6 +284,7 @@ public class TransactionLogBloomCacherTest {
             null,
             null,
             null,
+            null,
             new MainnetBlockHeaderFunctions());
     testHash = fakeHeader.getHash();
     when(blockchain.getBlockHeader(number)).thenReturn(Optional.of(fakeHeader));

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/chain/GenesisState.java

@@ -48,6 +48,7 @@ import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.MoreObjects;
 import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.bytes.Bytes32;
+import org.apache.tuweni.units.bigints.UInt64;
 
 public final class GenesisState {
 
@@ -218,6 +219,12 @@ public final class GenesisState {
         .parentBeaconBlockRoot(
             (isCancunAtGenesis(genesis) ? parseParentBeaconBlockRoot(genesis) : null))
         .requestsHash(isPragueAtGenesis(genesis) ? Hash.EMPTY_REQUESTS_HASH : null)
+        .targetBlobCount(
+            isPragueAtGenesis(genesis)
+                // TODO SLD EIP-7742 Currently defaulting to null due to dependency on web3j
+                // BlockHeader in CodeDelegationTransactionAcceptanceTest
+                ? genesis.getTargetBlobCount().map(UInt64::fromHexString).orElse(null)
+                : null)
         .buildBlockHeader();
   }
 

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/core/BlockHeader.java

@@ -28,6 +28,7 @@ import java.util.function.Supplier;
 import com.google.common.base.Suppliers;
 import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.bytes.Bytes32;
+import org.apache.tuweni.units.bigints.UInt64;
 
 /** A mined Ethereum block header. */
 public class BlockHeader extends SealableBlockHeader
@@ -65,6 +66,7 @@ public class BlockHeader extends SealableBlockHeader
       final BlobGas excessBlobGas,
       final Bytes32 parentBeaconBlockRoot,
       final Hash requestsHash,
+      final UInt64 targetBlobCount,
       final BlockHeaderFunctions blockHeaderFunctions) {
     super(
         parentHash,
@@ -86,7 +88,8 @@ public class BlockHeader extends SealableBlockHeader
         blobGasUsed,
         excessBlobGas,
         parentBeaconBlockRoot,
-        requestsHash);
+        requestsHash,
+        targetBlobCount);
     this.nonce = nonce;
     this.hash = Suppliers.memoize(() -> blockHeaderFunctions.hash(this));
     this.parsedExtraData = Suppliers.memoize(() -> blockHeaderFunctions.parseExtraData(this));
@@ -187,6 +190,9 @@ public class BlockHeader extends SealableBlockHeader
 
       if (requestsHash == null) break;
       out.writeBytes(requestsHash);
+
+      if (targetBlobCount == null) break;
+      out.writeUInt64Scalar(targetBlobCount);
     } while (false);
     out.endList();
   }
@@ -219,6 +225,7 @@ public class BlockHeader extends SealableBlockHeader
         !input.isEndOfCurrentList() ? BlobGas.of(input.readUInt64Scalar()) : null;
     final Bytes32 parentBeaconBlockRoot = !input.isEndOfCurrentList() ? input.readBytes32() : null;
     final Hash requestsHash = !input.isEndOfCurrentList() ? Hash.wrap(input.readBytes32()) : null;
+    final UInt64 targetBlobCount = !input.isEndOfCurrentList() ? input.readUInt64Scalar() : null;
     input.leaveList();
     return new BlockHeader(
         parentHash,
@@ -242,6 +249,7 @@ public class BlockHeader extends SealableBlockHeader
         excessBlobGas,
         parentBeaconBlockRoot,
         requestsHash,
+        targetBlobCount,
         blockHeaderFunctions);
   }
 
@@ -295,6 +303,9 @@ public class BlockHeader extends SealableBlockHeader
     if (requestsHash != null) {
       sb.append("requestsHash=").append(requestsHash);
     }
+    if (targetBlobCount != null) {
+      sb.append("targetBlobCount=").append(targetBlobCount);
+    }
     return sb.append("}").toString();
   }
 
@@ -329,6 +340,7 @@ public class BlockHeader extends SealableBlockHeader
             .getRequestsHash()
             .map(h -> Hash.fromHexString(h.toHexString()))
             .orElse(null),
+        pluginBlockHeader.getTargetBlobCount().orElse(null),
         blockHeaderFunctions);
   }
 

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/core/BlockHeaderBuilder.java

@@ -30,6 +30,7 @@ import java.util.OptionalLong;
 
 import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.bytes.Bytes32;
+import org.apache.tuweni.units.bigints.UInt64;
 
 /** A utility class for building block headers. */
 public class BlockHeaderBuilder {
@@ -76,6 +77,7 @@ public class BlockHeaderBuilder {
   private Long blobGasUsed = null;
   private BlobGas excessBlobGas = null;
   private Bytes32 parentBeaconBlockRoot = null;
+  private UInt64 targetBlobCount = null;
 
   public static BlockHeaderBuilder create() {
     return new BlockHeaderBuilder();
@@ -124,7 +126,8 @@ public class BlockHeaderBuilder {
         .blobGasUsed(header.getBlobGasUsed().orElse(null))
         .excessBlobGas(header.getExcessBlobGas().orElse(null))
         .parentBeaconBlockRoot(header.getParentBeaconBlockRoot().orElse(null))
-        .requestsHash(header.getRequestsHash().orElse(null));
+        .requestsHash(header.getRequestsHash().orElse(null))
+        .targetBlobCount(header.getTargetBlobCount().orElse(null));
   }
 
   public static BlockHeaderBuilder fromBuilder(final BlockHeaderBuilder fromBuilder) {
@@ -149,6 +152,7 @@ public class BlockHeaderBuilder {
             .excessBlobGas(fromBuilder.excessBlobGas)
             .parentBeaconBlockRoot(fromBuilder.parentBeaconBlockRoot)
             .requestsHash(fromBuilder.requestsHash)
+            .targetBlobCount(fromBuilder.targetBlobCount)
             .blockHeaderFunctions(fromBuilder.blockHeaderFunctions);
     toBuilder.nonce = fromBuilder.nonce;
     return toBuilder;
@@ -179,6 +183,7 @@ public class BlockHeaderBuilder {
         excessBlobGas,
         parentBeaconBlockRoot,
         requestsHash,
+        targetBlobCount,
         blockHeaderFunctions);
   }
 
@@ -194,7 +199,8 @@ public class BlockHeaderBuilder {
         timestamp,
         baseFee,
         mixHashOrPrevRandao,
-        parentBeaconBlockRoot);
+        parentBeaconBlockRoot,
+        targetBlobCount);
   }
 
   public SealableBlockHeader buildSealableBlockHeader() {
@@ -220,7 +226,8 @@ public class BlockHeaderBuilder {
         blobGasUsed,
         excessBlobGas,
         parentBeaconBlockRoot,
-        requestsHash);
+        requestsHash,
+        targetBlobCount);
   }
 
   private void validateBlockHeader() {
@@ -260,6 +267,7 @@ public class BlockHeaderBuilder {
     baseFee(processableBlockHeader.getBaseFee().orElse(null));
     processableBlockHeader.getPrevRandao().ifPresent(this::prevRandao);
     processableBlockHeader.getParentBeaconBlockRoot().ifPresent(this::parentBeaconBlockRoot);
+    processableBlockHeader.getTargetBlobCount().ifPresent(this::targetBlobCount);
     return this;
   }
 
@@ -285,6 +293,7 @@ public class BlockHeaderBuilder {
     sealableBlockHeader.getExcessBlobGas().ifPresent(this::excessBlobGas);
     sealableBlockHeader.getParentBeaconBlockRoot().ifPresent(this::parentBeaconBlockRoot);
     requestsHash(sealableBlockHeader.getRequestsHash().orElse(null));
+    sealableBlockHeader.getTargetBlobCount().ifPresent(this::targetBlobCount);
     return this;
   }
 
@@ -418,4 +427,9 @@ public class BlockHeaderBuilder {
     this.parentBeaconBlockRoot = parentBeaconBlockRoot;
     return this;
   }
+
+  public BlockHeaderBuilder targetBlobCount(final UInt64 targetBlobCount) {
+    this.targetBlobCount = targetBlobCount;
+    return this;
+  }
 }

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/core/ProcessableBlockHeader.java

@@ -23,6 +23,7 @@ import java.util.Optional;
 
 import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.bytes.Bytes32;
+import org.apache.tuweni.units.bigints.UInt64;
 
 /** A block header capable of being processed. */
 public class ProcessableBlockHeader
@@ -46,6 +47,8 @@ public class ProcessableBlockHeader
   protected final Bytes32 mixHashOrPrevRandao;
   // parentBeaconBlockRoot is included for Cancun
   protected final Bytes32 parentBeaconBlockRoot;
+  // TODO SLD Quantity or UInt64Value<UInt64> instead?
+  protected final UInt64 targetBlobCount;
 
   protected ProcessableBlockHeader(
       final Hash parentHash,
@@ -56,7 +59,8 @@ public class ProcessableBlockHeader
       final long timestamp,
       final Wei baseFee,
       final Bytes32 mixHashOrPrevRandao,
-      final Bytes32 parentBeaconBlockRoot) {
+      final Bytes32 parentBeaconBlockRoot,
+      final UInt64 targetBlobCount) {
     this.parentHash = parentHash;
     this.coinbase = coinbase;
     this.difficulty = difficulty;
@@ -66,6 +70,7 @@ public class ProcessableBlockHeader
     this.baseFee = baseFee;
     this.mixHashOrPrevRandao = mixHashOrPrevRandao;
     this.parentBeaconBlockRoot = parentBeaconBlockRoot;
+    this.targetBlobCount = targetBlobCount;
   }
 
   /**
@@ -178,6 +183,16 @@ public class ProcessableBlockHeader
     return Optional.ofNullable(parentBeaconBlockRoot);
   }
 
+  /**
+   * Returns the target blob count if available.
+   *
+   * @return the target blob count if available.
+   */
+  @Override
+  public Optional<UInt64> getTargetBlobCount() {
+    return Optional.ofNullable(targetBlobCount);
+  }
+
   public String toLogString() {
     return getNumber() + " (time: " + getTimestamp() + ")";
   }

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/core/SealableBlockHeader.java

@@ -24,6 +24,7 @@ import java.util.Optional;
 
 import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.bytes.Bytes32;
+import org.apache.tuweni.units.bigints.UInt64;
 
 /** A block header capable of being sealed. */
 public class SealableBlockHeader extends ProcessableBlockHeader {
@@ -69,7 +70,8 @@ public class SealableBlockHeader extends ProcessableBlockHeader {
       final Long blobGasUsed,
       final BlobGas excessBlobGas,
       final Bytes32 parentBeaconBlockRoot,
-      final Hash requestsHash) {
+      final Hash requestsHash,
+      final UInt64 targetBlobCount) {
     super(
         parentHash,
         coinbase,
@@ -79,7 +81,8 @@ public class SealableBlockHeader extends ProcessableBlockHeader {
         timestamp,
         baseFee,
         mixHashOrPrevRandao,
-        parentBeaconBlockRoot);
+        parentBeaconBlockRoot,
+        targetBlobCount);
     this.ommersHash = ommersHash;
     this.stateRoot = stateRoot;
     this.transactionsRoot = transactionsRoot;

ethereum/core/src/test-support/java/org/hyperledger/besu/ethereum/core/BlockHeaderTestFixture.java

@@ -25,6 +25,7 @@ import java.util.Optional;
 
 import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.bytes.Bytes32;
+import org.apache.tuweni.units.bigints.UInt64;
 
 public class BlockHeaderTestFixture {
 
@@ -55,6 +56,7 @@ public class BlockHeaderTestFixture {
   private Optional<BlobGas> excessBlobGas = Optional.empty();
   private Optional<Long> blobGasUsed = Optional.empty();
   private Optional<Bytes32> parentBeaconBlockRoot = Optional.empty();
+  private Optional<UInt64> targetBlobCount = Optional.empty();
 
   public BlockHeader buildHeader() {
     final BlockHeaderBuilder builder = BlockHeaderBuilder.create();
@@ -80,6 +82,7 @@ public class BlockHeaderTestFixture {
     blobGasUsed.ifPresent(builder::blobGasUsed);
     requestsHash.ifPresent(builder::requestsHash);
     parentBeaconBlockRoot.ifPresent(builder::parentBeaconBlockRoot);
+    targetBlobCount.ifPresent(builder::targetBlobCount);
     builder.blockHeaderFunctions(blockHeaderFunctions);
 
     return builder.buildBlockHeader();
@@ -201,4 +204,9 @@ public class BlockHeaderTestFixture {
     this.parentBeaconBlockRoot = parentBeaconBlockRoot;
     return this;
   }
+
+  public BlockHeaderTestFixture targetBlobCount(final UInt64 targetBlobCount) {
+    this.targetBlobCount = Optional.of(targetBlobCount);
+    return this;
+  }
 }

ethereum/core/src/test/java/org/hyperledger/besu/ethereum/chain/GenesisStateTest.java

@@ -31,6 +31,7 @@ import java.util.stream.Stream;
 
 import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.units.bigints.UInt256;
+import org.apache.tuweni.units.bigints.UInt64;
 import org.bouncycastle.util.encoders.Hex;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtensionContext;
@@ -287,10 +288,6 @@ final class GenesisStateTest {
             GenesisStateTest.class.getResource("genesis_prague.json"),
             ProtocolScheduleFixture.MAINNET);
     final BlockHeader header = genesisState.getBlock().getHeader();
-    assertThat(header.getHash())
-        .isEqualTo(
-            Hash.fromHexString(
-                "0x554807b22674e6d335f734485993857bbad7a9543affb0663a10c14d78135ec7"));
     assertThat(header.getGasLimit()).isEqualTo(0x2fefd8);
     assertThat(header.getGasUsed()).isZero();
     assertThat(header.getNumber()).isZero();
@@ -331,6 +328,13 @@ final class GenesisStateTest {
         .isEqualTo(
             Hash.fromHexString(
                 "0x6036c41849da9c076ed79654d434017387a88fb833c2856b32e18218b3341c5f"));
+    assertThat(header.getTargetBlobCount().isPresent()).isTrue();
+    assertThat(header.getTargetBlobCount().get()).isEqualTo(UInt64.ONE);
+
+    assertThat(header.getHash())
+        .isEqualTo(
+            Hash.fromHexString(
+                "0xdbc64edecb3a432e48cbd270b4a248ffc611b5f3dd666c8a10d546672cae17bd"));
   }
 
   @Test

ethereum/core/src/test/java/org/hyperledger/besu/ethereum/trie/diffbased/bonsai/LogRollingTests.java

@@ -99,6 +99,7 @@ class LogRollingTests {
           null,
           null,
           null,
+          null,
           new MainnetBlockHeaderFunctions());
   private static final BlockHeader headerTwo =
       new BlockHeader(
@@ -123,6 +124,7 @@ class LogRollingTests {
           null,
           null,
           null,
+          null,
           new MainnetBlockHeaderFunctions());
 
   @BeforeEach

ethereum/core/src/test/resources/org/hyperledger/besu/ethereum/chain/genesis_prague.json

@@ -4073,5 +4073,6 @@
   "number": "0x0",
   "gasUsed": "0x0",
   "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
-  "baseFeePerGas": "0x3b9aca00"
+  "baseFeePerGas": "0x3b9aca00",
+  "targetBlobCount": "0x1"
 }

ethereum/eth/src/test/java/org/hyperledger/besu/ethereum/eth/messages/MessageWrapperTest.java

@@ -398,6 +398,7 @@ public class MessageWrapperTest {
           null,
           null,
           null,
+          null,
           new MainnetBlockHeaderFunctions());
     }
   }

ethereum/eth/src/test/java/org/hyperledger/besu/ethereum/eth/sync/backwardsync/ChainForTestCreator.java

@@ -61,6 +61,7 @@ public class ChainForTestCreator {
         null,
         null,
         null,
+        null,
         new MainnetBlockHeaderFunctions());
   }
 
@@ -89,6 +90,7 @@ public class ChainForTestCreator {
         blockHeader.getExcessBlobGas().orElse(null),
         blockHeader.getParentBeaconBlockRoot().orElse(null),
         blockHeader.getRequestsHash().orElse(null),
+        blockHeader.getTargetBlobCount().orElse(null),
         new MainnetBlockHeaderFunctions());
   }
 
@@ -139,6 +141,7 @@ public class ChainForTestCreator {
         null,
         null,
         null,
+        null,
         new MainnetBlockHeaderFunctions());
   }
 }

ethereum/referencetests/src/main/java/org/hyperledger/besu/ethereum/referencetests/BlockchainReferenceTestCaseSpec.java

@@ -195,6 +195,7 @@ public class BlockchainReferenceTestCaseSpec {
           excessBlobGas != null ? BlobGas.fromHexString(excessBlobGas) : null,
           parentBeaconBlockRoot != null ? Bytes32.fromHexString(parentBeaconBlockRoot) : null,
           requestsHash != null ? Hash.fromHexString(requestsHash) : null,
+          null, // TODO SLD EIP-7742 use targetBlobCount when reference tests are updated
           new BlockHeaderFunctions() {
             @Override
             public Hash hash(final BlockHeader header) {

ethereum/referencetests/src/main/java/org/hyperledger/besu/ethereum/referencetests/ReferenceTestEnv.java

@@ -146,6 +146,7 @@ public class ReferenceTestEnv extends BlockHeader {
         currentExcessBlobGas == null ? null : BlobGas.of(Long.decode(currentExcessBlobGas)),
         beaconRoot == null ? null : Bytes32.fromHexString(beaconRoot),
         null, // requestsHash
+        null, // TODO SLD EIP-7742 use targetBlobCount when reference tests are updated
         new MainnetBlockHeaderFunctions());
     this.parentDifficulty = parentDifficulty;
     this.parentBaseFee = parentBaseFee;

plugin-api/build.gradle

@@ -71,7 +71,7 @@ Calculated : ${currentHash}
 tasks.register('checkAPIChanges', FileStateChecker) {
   description = "Checks that the API for the Plugin-API project does not change without deliberate thought"
   files = sourceSets.main.allJava.files
-  knownHash = 'G3cpM0HGYp4G1u6dN2CRZiEEsgce6jy9rkIlT1blUb4='
+  knownHash = 'uNQzVjMa7m1fw3d10NuVOjmzGxmCkgZd88yGFgP3qoY='
 }
 check.dependsOn('checkAPIChanges')
 

plugin-api/src/main/java/org/hyperledger/besu/plugin/data/ProcessableBlockHeader.java

@@ -22,6 +22,7 @@ import org.hyperledger.besu.plugin.Unstable;
 import java.util.Optional;
 
 import org.apache.tuweni.bytes.Bytes32;
+import org.apache.tuweni.units.bigints.UInt64;
 
 /**
  * The minimum set of data for a BlockHeader, as defined in the <a href=
@@ -105,4 +106,15 @@ public interface ProcessableBlockHeader {
    */
   @Unstable
   Optional<? extends Bytes32> getParentBeaconBlockRoot();
+
+  /**
+   * The target_blob_count of this header.
+   *
+   * @return The target blob count of this header.
+   */
+  @Unstable
+  // TODO SLD should be Quantity or new subclass of Quantity?
+  default Optional<UInt64> getTargetBlobCount() {
+    return Optional.empty();
+  }
 }