[codex] balance mimicry execution peers and discovery refresh

.github/workflows/govulncheck.yaml

@@ -18,7 +18,7 @@ jobs:
     steps:
       - uses: actions/setup-go@d35c59abb061a4a6fb18e82ac0862c26744d6ab5 # v5.5.0
         with:
-          go-version: '1.25.x'
+          go-version: '1.25.10'
           check-latest: true
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
       - name: Install govulncheck

go.mod

@@ -60,8 +60,8 @@ require (
 	go.opentelemetry.io/otel/sdk v1.40.0
 	go.opentelemetry.io/otel/trace v1.40.0
 	go.uber.org/mock v0.5.2
-	golang.org/x/crypto v0.47.0
-	golang.org/x/sync v0.19.0
+	golang.org/x/crypto v0.50.0
+	golang.org/x/sync v0.20.0
 	golang.org/x/time v0.13.0
 	google.golang.org/grpc v1.79.3
 	google.golang.org/protobuf v1.36.11
@@ -297,13 +297,13 @@ require (
 	go.uber.org/zap v1.27.1 // indirect
 	go.yaml.in/yaml/v2 v2.4.3 // indirect
 	golang.org/x/exp v0.0.0-20251002181428-27f1f14c8bb9 // indirect
-	golang.org/x/mod v0.31.0 // indirect
-	golang.org/x/net v0.49.0 // indirect
+	golang.org/x/mod v0.34.0 // indirect
+	golang.org/x/net v0.53.0 // indirect
 	golang.org/x/oauth2 v0.34.0 // indirect
-	golang.org/x/sys v0.40.0 // indirect
-	golang.org/x/telemetry v0.0.0-20251203150158-8fff8a5912fc // indirect
-	golang.org/x/text v0.33.0 // indirect
-	golang.org/x/tools v0.40.0 // indirect
+	golang.org/x/sys v0.43.0 // indirect
+	golang.org/x/telemetry v0.0.0-20260311193753-579e4da9a98c // indirect
+	golang.org/x/text v0.36.0 // indirect
+	golang.org/x/tools v0.43.0 // indirect
 	google.golang.org/genproto/googleapis/api v0.0.0-20260128011058-8636f8732409 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20260128011058-8636f8732409 // indirect
 	gopkg.in/Knetic/govaluate.v3 v3.0.0 // indirect

go.sum

@@ -883,17 +883,17 @@ golang.org/x/crypto v0.6.0/go.mod h1:OFC/31mSvZgRz0V1QTNCzfAI1aIRzbiufJtkMIlEp58
 golang.org/x/crypto v0.8.0/go.mod h1:mRqEX+O9/h5TFCrQhkgjo2yKi0yYA+9ecGkdQoHrywE=
 golang.org/x/crypto v0.12.0/go.mod h1:NF0Gs7EO5K4qLn+Ylc+fih8BSTeIjAP05siRnAh98yw=
 golang.org/x/crypto v0.18.0/go.mod h1:R0j02AL6hcrfOiy9T4ZYp/rcWeMxM3L6QYxlOuEG1mg=
-golang.org/x/crypto v0.47.0 h1:V6e3FRj+n4dbpw86FJ8Fv7XVOql7TEwpHapKoMJ/GO8=
-golang.org/x/crypto v0.47.0/go.mod h1:ff3Y9VzzKbwSSEzWqJsJVBnWmRwRSHt/6Op5n9bQc4A=
+golang.org/x/crypto v0.50.0 h1:zO47/JPrL6vsNkINmLoo/PH1gcxpls50DNogFvB5ZGI=
+golang.org/x/crypto v0.50.0/go.mod h1:3muZ7vA7PBCE6xgPX7nkzzjiUq87kRItoJQM1Yo8S+Q=
 golang.org/x/exp v0.0.0-20180321215751-8460e604b9de/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20251002181428-27f1f14c8bb9 h1:TQwNpfvNkxAVlItJf6Cr5JTsVZoC/Sj7K3OZv2Pc14A=
 golang.org/x/exp v0.0.0-20251002181428-27f1f14c8bb9/go.mod h1:TwQYMMnGpvZyc+JpB/UAuTNIsVJifOlSkrZkhcvpVUk=
 golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
-golang.org/x/mod v0.31.0 h1:HaW9xtz0+kOcWKwli0ZXy79Ix+UW/vOfmWI5QVd2tgI=
-golang.org/x/mod v0.31.0/go.mod h1:43JraMp9cGx1Rx3AqioxrbrhNsLl2l/iNAvuBkrezpg=
+golang.org/x/mod v0.34.0 h1:xIHgNUUnW6sYkcM5Jleh05DvLOtwc6RitGHbDk4akRI=
+golang.org/x/mod v0.34.0/go.mod h1:ykgH52iCZe79kzLLMhyCUzhMci+nQj+0XkbXpNYtVjY=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
@@ -914,8 +914,8 @@ golang.org/x/net v0.9.0/go.mod h1:d48xBJpPfHeWQsugry2m+kC02ZBRGRgulfHnEXEuWns=
 golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
 golang.org/x/net v0.14.0/go.mod h1:PpSgVXXLK0OxS0F31C1/tv6XNguvCrnXIDrFMspZIUI=
 golang.org/x/net v0.20.0/go.mod h1:z8BVo6PvndSri0LbOE3hAn0apkU+1YvI6E70E9jsnvY=
-golang.org/x/net v0.49.0 h1:eeHFmOGUTtaaPSGNmjBKpbng9MulQsJURQUAfUwY++o=
-golang.org/x/net v0.49.0/go.mod h1:/ysNB2EvaqvesRkuLAyjI1ycPZlQHM3q01F02UY/MV8=
+golang.org/x/net v0.53.0 h1:d+qAbo5L0orcWAr0a9JweQpjXF19LMXJE8Ey7hwOdUA=
+golang.org/x/net v0.53.0/go.mod h1:JvMuJH7rrdiCfbeHoo3fCQU24Lf5JJwT9W3sJFulfgs=
 golang.org/x/oauth2 v0.34.0 h1:hqK/t4AKgbqWkdkcAeI8XLmbK+4m4G5YeQRrmiotGlw=
 golang.org/x/oauth2 v0.34.0/go.mod h1:lzm5WQJQwKZ3nwavOZ3IS5Aulzxi68dUSgRHujetwEA=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -925,8 +925,8 @@ golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.19.0 h1:vV+1eWNmZ5geRlYjzm2adRgW2/mcpevXNg50YZtPCE4=
-golang.org/x/sync v0.19.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
+golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -959,19 +959,19 @@ golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.16.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
-golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
-golang.org/x/telemetry v0.0.0-20251203150158-8fff8a5912fc h1:bH6xUXay0AIFMElXG2rQ4uiE+7ncwtiOdPfYK1NK2XA=
-golang.org/x/telemetry v0.0.0-20251203150158-8fff8a5912fc/go.mod h1:hKdjCMrbv9skySur+Nek8Hd0uJ0GuxJIoIX2payrIdQ=
+golang.org/x/sys v0.43.0 h1:Rlag2XtaFTxp19wS8MXlJwTvoh8ArU6ezoyFsMyCTNI=
+golang.org/x/sys v0.43.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/telemetry v0.0.0-20260311193753-579e4da9a98c h1:6a8FdnNk6bTXBjR4AGKFgUKuo+7GnR3FX5L7CbveeZc=
+golang.org/x/telemetry v0.0.0-20260311193753-579e4da9a98c/go.mod h1:TpUTTEp9frx7rTdLpC9gFG9kdI7zVLFTFFlqaH2Cncw=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/term v0.5.0/go.mod h1:jMB1sMXY+tzblOD4FWmEbocvup2/aLOaQEp7JmGp78k=
 golang.org/x/term v0.7.0/go.mod h1:P32HKFT3hSsZrRxla30E9HqToFYAQPCMs/zFMBUFqPY=
 golang.org/x/term v0.8.0/go.mod h1:xPskH00ivmX89bAKVGSKKtLOWNx2+17Eiy94tnKShWo=
 golang.org/x/term v0.11.0/go.mod h1:zC9APTIj3jG3FdV/Ons+XE1riIZXG4aZ4GTHiPZJPIU=
 golang.org/x/term v0.16.0/go.mod h1:yn7UURbUtPyrVJPGPq404EukNFxcm/foM+bV/bfcDsY=
-golang.org/x/term v0.39.0 h1:RclSuaJf32jOqZz74CkPA9qFuVTX7vhLlpfj/IGWlqY=
-golang.org/x/term v0.39.0/go.mod h1:yxzUCTP/U+FzoxfdKmLaA0RV1WgE0VY7hXBwKtY/4ww=
+golang.org/x/term v0.42.0 h1:UiKe+zDFmJobeJ5ggPwOshJIVt6/Ft0rcfrXZDLWAWY=
+golang.org/x/term v0.42.0/go.mod h1:Dq/D+snpsbazcBG5+F9Q1n2rXV8Ma+71xEjTRufARgY=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
@@ -981,8 +981,8 @@ golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
 golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 golang.org/x/text v0.12.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
 golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
-golang.org/x/text v0.33.0 h1:B3njUFyqtHDUI5jMn1YIr5B0IE2U0qck04r6d4KPAxE=
-golang.org/x/text v0.33.0/go.mod h1:LuMebE6+rBincTi9+xWTY8TztLzKHc/9C1uBCG27+q8=
+golang.org/x/text v0.36.0 h1:JfKh3XmcRPqZPKevfXVpI1wXPTqbkE5f7JA92a55Yxg=
+golang.org/x/text v0.36.0/go.mod h1:NIdBknypM8iqVmPiuco0Dh6P5Jcdk8lJL0CUebqK164=
 golang.org/x/time v0.13.0 h1:eUlYslOIt32DgYD6utsuUeHs4d7AsEYLuIAdg7FlYgI=
 golang.org/x/time v0.13.0/go.mod h1:eL/Oa2bBBK0TkX57Fyni+NgnyQQN4LitPmob2Hjnqw4=
 golang.org/x/tools v0.0.0-20180525024113-a5b4c53f6e8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
@@ -993,8 +993,8 @@ golang.org/x/tools v0.0.0-20201224043029-2b0845dc783e/go.mod h1:emZCQorbCU4vsT4f
 golang.org/x/tools v0.0.0-20210106214847-113979e3529a/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
 golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
-golang.org/x/tools v0.40.0 h1:yLkxfA+Qnul4cs9QA3KnlFu0lVmd8JJfoq+E41uSutA=
-golang.org/x/tools v0.40.0/go.mod h1:Ik/tzLRlbscWpqqMRjyWYDisX8bG13FrdXp3o4Sr9lc=
+golang.org/x/tools v0.43.0 h1:12BdW9CeB3Z+J/I/wj34VMl8X+fEXBxVR90JeMX5E7s=
+golang.org/x/tools v0.43.0/go.mod h1:uHkMso649BX2cZK6+RpuIPXS3ho2hZo4FVwfoy1vIk0=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

pkg/discovery/p2p/xatu/xatu.go

@@ -224,16 +224,36 @@ func (c *Coordinator) startCrons(ctx context.Context) error {
 					return
 				}
 
-				if err = c.discV5.UpdateBootNodes([]string{res.NodeRecord}); err != nil {
-					c.log.WithError(err).Error("Failed to update discV5 boot nodes")
+				nodeRecord := res.GetNodeRecord()
+
+				if c.config.DiscV4 && c.discV4 != nil {
+					if err = c.discV4.UpdateBootNodes([]string{nodeRecord}); err != nil {
+						c.log.WithError(err).Error("Failed to update discV4 boot nodes")
+
+						return
+					}
+
+					if err = c.discV4.Start(ctx); err != nil {
+						c.log.WithError(err).Error("Failed to start discV4")
+
+						return
+					}
 
 					return
 				}
 
-				if err := c.discV5.Start(ctx); err != nil {
-					c.log.WithError(err).Error("Failed to start discV5")
+				if c.config.DiscV5 && c.discV5 != nil {
+					if err = c.discV5.UpdateBootNodes([]string{nodeRecord}); err != nil {
+						c.log.WithError(err).Error("Failed to update discV5 boot nodes")
 
-					return
+						return
+					}
+
+					if err := c.discV5.Start(ctx); err != nil {
+						c.log.WithError(err).Error("Failed to start discV5")
+
+						return
+					}
 				}
 			},
 			ctx,

pkg/server/persistence/integration_test.go

@@ -588,6 +588,83 @@ func TestPersistenceIntegration(t *testing.T) {
 			assert.GreaterOrEqual(t, len(available), 1)
 		})
 
+		t.Run("ListAvailableExecutionNodeRecordsBalancesImplementations", func(t *testing.T) {
+			networkID := uint64(424242)
+			forkIDHash := []byte{0xaa, 0xbb, 0xcc, 0xdd}
+			baseTime := time.Now().Add(-2 * time.Hour)
+
+			testData := []struct {
+				enr        string
+				name       string
+				createTime time.Time
+			}{
+				{
+					enr:        "enr:-IS4QBalancedGeth1-abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890",
+					name:       "Geth/v1.0.0",
+					createTime: baseTime,
+				},
+				{
+					enr:        "enr:-IS4QBalancedGeth2-abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890",
+					name:       "Geth/v1.0.1",
+					createTime: baseTime.Add(time.Minute),
+				},
+				{
+					enr:        "enr:-IS4QBalancedGeth3-abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890",
+					name:       "Geth/v1.0.2",
+					createTime: baseTime.Add(2 * time.Minute),
+				},
+				{
+					enr:        "enr:-IS4QBalancedBesu1-abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890",
+					name:       "Besu/v1.0.0",
+					createTime: baseTime.Add(time.Hour),
+				},
+				{
+					enr:        "enr:-IS4QBalancedReth1-abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890",
+					name:       "Reth/v1.0.0",
+					createTime: baseTime.Add(time.Hour + time.Minute),
+				},
+			}
+
+			for _, td := range testData {
+				nodeRecord := createTestNodeRecord(td.enr)
+				nodeRecord.ETH2 = nil
+				err := tc.Client.InsertNodeRecords(ctx, []*node.Record{nodeRecord})
+				require.NoError(t, err)
+
+				execRecord := createTestExecutionRecord(td.enr)
+				execRecord.Name = td.name
+				execRecord.NetworkID = fmt.Sprint(networkID)
+				execRecord.ForkIDHash = forkIDHash
+				err = tc.Client.InsertNodeRecordExecution(ctx, execRecord)
+				require.NoError(t, err)
+
+				_, err = tc.DB.ExecContext(ctx, "UPDATE node_record_execution SET create_time = $1 WHERE enr = $2", td.createTime, td.enr)
+				require.NoError(t, err)
+			}
+
+			available, err := tc.Client.ListAvailableExecutionNodeRecords(ctx, "requesting-client", nil, []uint64{networkID}, [][]byte{forkIDHash}, nil, 3)
+			require.NoError(t, err)
+			require.Len(t, available, 3)
+
+			availableByENR := map[string]bool{}
+			for _, enr := range available {
+				availableByENR[*enr] = true
+			}
+
+			assert.True(t, availableByENR["enr:-IS4QBalancedBesu1-abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"])
+			assert.True(t, availableByENR["enr:-IS4QBalancedReth1-abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"])
+
+			gethRecords := 0
+
+			for _, td := range testData {
+				if strings.HasPrefix(td.name, "Geth/") && availableByENR[td.enr] {
+					gethRecords++
+				}
+			}
+
+			assert.Equal(t, 1, gethRecords)
+		})
+
 		t.Run("ListAvailableConsensusNodeRecords", func(t *testing.T) {
 			// Create consensus node records with different characteristics
 			testData := []struct {

pkg/server/persistence/node_record_activity.go

@@ -3,6 +3,7 @@ package persistence
 import (
 	"context"
 	"fmt"
+	"strings"
 	"time"
 
 	"github.com/ethpandaops/xatu/pkg/server/persistence/node"
@@ -27,6 +28,15 @@ type AvailableConsensusNodeRecord struct {
 
 var availableConsensusNodeRecordStruct = sqlbuilder.NewStruct(new(AvailableConsensusNodeRecord)).For(sqlbuilder.PostgreSQL)
 
+var executionClientImplementations = []string{
+	"besu",
+	"erigon",
+	"ethrex",
+	"geth",
+	"nethermind",
+	"reth",
+}
+
 func (c *Client) UpsertNodeRecordActivities(ctx context.Context, activities []*node.Activity) error {
 	// Return early if there are no activities to upsert
 	if len(activities) == 0 {
@@ -57,6 +67,84 @@ func (c *Client) UpsertNodeRecordActivities(ctx context.Context, activities []*n
 }
 
 func (c *Client) ListAvailableExecutionNodeRecords(ctx context.Context, clientID string, ignoredNodeRecords []string, networkIds []uint64, forkIDHashes [][]byte, capabilities []string, limit int) ([]*string, error) {
+	if limit <= 0 {
+		return []*string{}, nil
+	}
+
+	candidatesByImplementation := make(map[string][]*string, len(executionClientImplementations))
+	for _, implementation := range executionClientImplementations {
+		records, err := c.listAvailableExecutionNodeRecords(ctx, clientID, ignoredNodeRecords, networkIds, forkIDHashes, capabilities, implementation, limit)
+		if err != nil {
+			return nil, err
+		}
+
+		candidatesByImplementation[implementation] = records
+	}
+
+	nodeRecords := make([]*string, 0, limit)
+	seen := make(map[string]struct{}, limit)
+
+	addRecord := func(record *string) bool {
+		if record == nil {
+			return len(nodeRecords) < limit
+		}
+
+		if _, ok := seen[*record]; ok {
+			return len(nodeRecords) < limit
+		}
+
+		seen[*record] = struct{}{}
+		nodeRecords = append(nodeRecords, record)
+
+		return len(nodeRecords) < limit
+	}
+
+	for i := 0; len(nodeRecords) < limit; i++ {
+		added := false
+
+		for _, implementation := range executionClientImplementations {
+			candidates := candidatesByImplementation[implementation]
+			if i >= len(candidates) {
+				continue
+			}
+
+			added = true
+
+			if !addRecord(candidates[i]) {
+				break
+			}
+		}
+
+		if !added {
+			break
+		}
+	}
+
+	if len(nodeRecords) < limit {
+		fillIgnoredNodeRecords := append([]string{}, ignoredNodeRecords...)
+
+		for _, record := range nodeRecords {
+			if record != nil {
+				fillIgnoredNodeRecords = append(fillIgnoredNodeRecords, *record)
+			}
+		}
+
+		records, err := c.listAvailableExecutionNodeRecords(ctx, clientID, fillIgnoredNodeRecords, networkIds, forkIDHashes, capabilities, "", limit-len(nodeRecords))
+		if err != nil {
+			return nil, err
+		}
+
+		for _, record := range records {
+			if !addRecord(record) {
+				break
+			}
+		}
+	}
+
+	return nodeRecords, nil
+}
+
+func (c *Client) listAvailableExecutionNodeRecords(ctx context.Context, clientID string, ignoredNodeRecords []string, networkIds []uint64, forkIDHashes [][]byte, capabilities []string, implementation string, limit int) ([]*string, error) {
 	inr := make([]any, 0, len(ignoredNodeRecords))
 	for _, enr := range ignoredNodeRecords {
 		inr = append(inr, enr)
@@ -129,6 +217,14 @@ func (c *Client) ListAvailableExecutionNodeRecords(ctx context.Context, clientID
 		}
 	}
 
+	if implementation != "" {
+		normalizedImplementation := strings.ToLower(implementation)
+		where = append(where, sb.Or(
+			sb.Equal("LOWER(nre.name)", normalizedImplementation),
+			sb.Like("LOWER(nre.name)", normalizedImplementation+"/%"),
+		))
+	}
+
 	sb.Where(where...)
 	sb.GroupBy("nre.enr")
 	sb.OrderBy("last_connect_time ASC")