Return all forks if needed

src/Nethermind/Nethermind.JsonRpc.Test/Modules/Eth/EthRpcModuleTests.cs

@@ -186,6 +186,27 @@ public async Task Eth_get_transaction_by_block_number_and_index_out_of_bounds()
         Assert.That(serialized, Is.EqualTo("{\"jsonrpc\":\"2.0\",\"result\":null,\"id\":67}"));
     }
 
+    [Test]
+    public async Task Eth_config_does_not_include_all_by_default()
+    {
+        using Context ctx = await Context.Create();
+        string serialized = await ctx.Test.TestEthRpc("eth_config");
+        JToken result = JToken.Parse(serialized)["result"]!;
+        result.Should().NotBeNull();
+        result["all"].Should().BeNull();
+    }
+
+    [Test]
+    public async Task Eth_config_returns_all_forks_when_requested()
+    {
+        using Context ctx = await Context.Create();
+        string serialized = await ctx.Test.TestEthRpc("eth_config", true);
+        JToken result = JToken.Parse(serialized)["result"]!;
+        result.Should().NotBeNull();
+        JArray allForks = (JArray)result["all"]!;
+        allForks.Count.Should().BeGreaterThan(0);
+    }
+
     [TestCase(false, "{\"jsonrpc\":\"2.0\",\"result\":{\"difficulty\":\"0xf4240\",\"extraData\":\"0x010203\",\"gasLimit\":\"0x3d0900\",\"gasUsed\":\"0x0\",\"hash\":\"0xa2a9f03b9493046696099d27b2612b99497aa1f392ec966716ab393c715a5bb6\",\"logsBloom\":\"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000\",\"miner\":\"0x0000000000000000000000000000000000000000\",\"mixHash\":\"0x2ba5557a4c62a513c7e56d1bf13373e0da6bec016755483e91589fe1c6d212e2\",\"nonce\":\"0x00000000000003e8\",\"number\":\"0x0\",\"parentHash\":\"0xff483e972a04a9a62bb4b7d04ae403c615604e4090521ecc5bb7af67f71be09c\",\"receiptsRoot\":\"0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421\",\"sha3Uncles\":\"0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347\",\"size\":\"0x201\",\"stateRoot\":\"0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421\",\"totalDifficulty\":\"0x0\",\"timestamp\":\"0xf4240\",\"transactions\":[],\"transactionsRoot\":\"0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421\",\"uncles\":[]},\"id\":67}")]
     [TestCase(true, "{\"jsonrpc\":\"2.0\",\"result\":{\"difficulty\":\"0xf4240\",\"extraData\":\"0x010203\",\"gasLimit\":\"0x3d0900\",\"gasUsed\":\"0x0\",\"hash\":\"0xa2a9f03b9493046696099d27b2612b99497aa1f392ec966716ab393c715a5bb6\",\"logsBloom\":\"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000\",\"miner\":\"0x0000000000000000000000000000000000000000\",\"mixHash\":\"0x2ba5557a4c62a513c7e56d1bf13373e0da6bec016755483e91589fe1c6d212e2\",\"nonce\":\"0x00000000000003e8\",\"number\":\"0x0\",\"parentHash\":\"0xff483e972a04a9a62bb4b7d04ae403c615604e4090521ecc5bb7af67f71be09c\",\"receiptsRoot\":\"0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421\",\"sha3Uncles\":\"0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347\",\"size\":\"0x201\",\"stateRoot\":\"0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421\",\"totalDifficulty\":\"0x0\",\"timestamp\":\"0xf4240\",\"baseFeePerGas\":\"0x0\",\"transactions\":[],\"transactionsRoot\":\"0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421\",\"uncles\":[]},\"id\":67}")]
     public async Task Eth_get_uncle_by_block_number_and_index(bool eip1559, string expectedJson)

src/Nethermind/Nethermind.JsonRpc/Data/ForkConfigSummary.cs

@@ -13,6 +13,8 @@ public class ForkConfigSummary
 
     [JsonIgnore(Condition = JsonIgnoreCondition.Never)]
     public required ForkConfig? Last { get; init; }
+
+    public IReadOnlyList<ForkConfig>? All { get; init; }
 }
 
 public class ForkConfig

src/Nethermind/Nethermind.JsonRpc/Modules/Eth/EthRpcModule.cs

@@ -1,7 +1,8 @@
-// SPDX-FileCopyrightText: 2023 Demerzel Solutions Limited
+// SPDX-FileCopyrightText: 2025 Demerzel Solutions Limited
 // SPDX-License-Identifier: LGPL-3.0-only
 
 using System;
+using System.Collections.Frozen;
 using System.Collections.Generic;
 using System.Linq;
 using System.Security;
@@ -67,6 +68,8 @@ public partial class EthRpcModule(
     IForkInfo forkInfo,
     ulong? secondsPerSlot) : IEthRpcModule
 {
+    private static FrozenDictionary<ForkId, ForkConfig>? forkConfigCache = null;
+
     protected readonly Encoding _messageEncoding = Encoding.UTF8;
     protected readonly IJsonRpcConfig _rpcConfig = rpcConfig ?? throw new ArgumentNullException(nameof(rpcConfig));
     protected readonly IBlockchainBridge _blockchainBridge = blockchainBridge ?? throw new ArgumentNullException(nameof(blockchainBridge));
@@ -802,38 +805,60 @@ private ResultWrapper<TResult> GetStateFailureResult<TResult>(BlockHeader header
         };
     }
 
-    public ResultWrapper<JsonNode> eth_config()
+    public ResultWrapper<JsonNode> eth_config(bool showAllForks = false)
     {
         ForkActivationsSummary forks = forkInfo.GetForkActivationsSummary(_blockFinder.Head?.Header);
 
-        return ResultWrapper<JsonNode>.Success(JsonNode.Parse(JsonSerializer.Serialize((new ForkConfigSummary
+        if (forkConfigCache is null)
         {
-            Current = GetForkConfig(forks.Current, _specProvider)!,
-            Next = GetForkConfig(forks.Next, _specProvider),
-            Last = GetForkConfig(forks.Last, _specProvider)
-        }), UnchangedDictionaryKeyOptions)));
+            ReadOnlySpan<Fork> forkSchedule = forkInfo.GetAllForks();
+            Dictionary<ForkId, ForkConfig> allForks = new(forkSchedule.Length);
+
+            foreach (Fork scheduledFork in forkSchedule)
+            {
+                allForks.Add(scheduledFork.Id, BuildForkConfig(scheduledFork, _specProvider));
+            }
+
+            forkConfigCache = allForks.ToFrozenDictionary();
+        }
 
-        static ForkConfig? GetForkConfig(Fork? fork, ISpecProvider specProvider)
+        List<ForkConfig>? allForkConfigs = null;
+
+        if (showAllForks)
         {
-            if (fork is null)
+            ReadOnlySpan<Fork> forkSchedule = forkInfo.GetAllForks();
+            allForkConfigs = new(forkSchedule.Length);
+
+            foreach (Fork scheduledFork in forkSchedule)
             {
-                return null;
+                allForkConfigs.Add(forkConfigCache[scheduledFork.Id]);
             }
+        }
 
-            IReleaseSpec? spec = specProvider.GetSpec(fork.Value.Activation.BlockNumber, fork.Value.Activation.Timestamp);
+        return ResultWrapper<JsonNode>.Success(JsonNode.Parse(JsonSerializer.Serialize(new ForkConfigSummary
+        {
+            Current = forkConfigCache[forks.Current.Id],
+            Next = forks.Next is null ? null : forkConfigCache[forks.Next.Value.Id],
+            Last = forks.Last is null ? null : forkConfigCache[forks.Last.Value.Id],
+            All = allForkConfigs
+        }, UnchangedDictionaryKeyOptions)));
+
+        static ForkConfig BuildForkConfig(Fork fork, ISpecProvider specProvider)
+        {
+            IReleaseSpec spec = specProvider.GetSpec(fork.Activation.BlockNumber, fork.Activation.Timestamp);
 
             return new ForkConfig
             {
-                ActivationTime = fork.Value.Activation.Timestamp is not null ? (int)fork.Value.Activation.Timestamp : null,
-                ActivationBlock = fork.Value.Activation.Timestamp is null ? (int)fork.Value.Activation.BlockNumber : null,
+                ActivationTime = fork.Activation.Timestamp is not null ? (int)fork.Activation.Timestamp : null,
+                ActivationBlock = fork.Activation.Timestamp is null ? (int)fork.Activation.BlockNumber : null,
                 BlobSchedule = spec.IsEip4844Enabled ? new BlobScheduleSettingsForRpc
                 {
                     BaseFeeUpdateFraction = (int)spec.BlobBaseFeeUpdateFraction,
                     Max = (int)spec.MaxBlobCount,
                     Target = (int)spec.TargetBlobCount,
                 } : null,
                 ChainId = specProvider.ChainId,
-                ForkId = fork.Value.Id.HashBytes,
+                ForkId = fork.Id.HashBytes,
                 Precompiles = spec.ListPrecompiles(),
                 SystemContracts = spec.ListSystemContracts(),
             };

src/Nethermind/Nethermind.JsonRpc/Modules/Eth/IEthRpcModule.cs

@@ -1,7 +1,6 @@
-// SPDX-FileCopyrightText: 2023 Demerzel Solutions Limited
+// SPDX-FileCopyrightText: 2025 Demerzel Solutions Limited
 // SPDX-License-Identifier: LGPL-3.0-only
 
-using System;
 using System.Collections.Generic;
 using System.Text.Json.Nodes;
 using System.Threading.Tasks;
@@ -289,7 +288,7 @@ ResultWrapper<TransactionForRpc> eth_getTransactionByBlockNumberAndIndex(
         [JsonRpcMethod(IsImplemented = true, Description = "Retrieves Account with code and no storageRoot via Address and Blocknumber", IsSharable = true)]
         ResultWrapper<AccountInfoForRpc?> eth_getAccountInfo([JsonRpcParameter(ExampleValue = "[\"0xaa00000000000000000000000000000000000000\", \"latest\"]")] Address accountAddress, BlockParameter? blockParameter = null);
 
-        [JsonRpcMethod(IsImplemented = true, Description = "Provides configuration data for the current and next fork", IsSharable = true)]
-        ResultWrapper<JsonNode> eth_config();
+        [JsonRpcMethod(IsImplemented = true, Description = "Provides configuration data for the current and next fork or the full fork schedule", IsSharable = true)]
+        ResultWrapper<JsonNode> eth_config([JsonRpcParameter(Description = "Returns every known fork when true", ExampleValue = "[true]")] bool showAllForks = false);
     }
 }

src/Nethermind/Nethermind.Network/ForkInfo.cs

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: 2022 Demerzel Solutions Limited
+// SPDX-FileCopyrightText: 2025 Demerzel Solutions Limited
 // SPDX-License-Identifier: LGPL-3.0-only
 
 using Force.Crc32;
@@ -176,5 +176,11 @@ public ForkActivationsSummary GetForkActivationsSummary(BlockHeader? head)
                 Last = isNextPresent ? new Fork(Forks[^1].Activation, Forks[^1].Id) : null,
             };
         }
+
+        public ReadOnlySpan<Fork> GetAllForks()
+        {
+            EnsureInitialized();
+            return Forks;
+        }
     }
 }

src/Nethermind/Nethermind.Network/IForkInfo.cs

@@ -3,6 +3,7 @@
 
 using Nethermind.Core;
 using Nethermind.Core.Specs;
+using System;
 
 namespace Nethermind.Network;
 
@@ -19,6 +20,8 @@ public interface IForkInfo
     ValidationResult ValidateForkId(ForkId peerId, BlockHeader? head);
 
     ForkActivationsSummary GetForkActivationsSummary(BlockHeader? head);
+
+    ReadOnlySpan<Fork> GetAllForks();
 }
 
 public readonly record struct Fork(ForkActivation Activation, ForkId Id);