diff --git a/config.go b/config.go
index 19c8ea3..e13c62c 100644
--- a/config.go
+++ b/config.go
@@ -328,6 +328,7 @@ type MemIAVLConfig struct {
 
 type StateStoreConfig struct {
 	Enable               bool      `toml:"enable"`
+	EVMSSSplit           bool      `toml:"evm_ss_split"`
 	DBDirectory          string    `toml:"db_directory"`
 	Backend              string    `toml:"backend"`
 	AsyncWriteBuffer     int       `toml:"async_write_buffer"`
diff --git a/defaults.go b/defaults.go
index f9bc7bd..e7b24af 100644
--- a/defaults.go
+++ b/defaults.go
@@ -296,6 +296,13 @@ func applyFullOverrides(cfg *SeiConfig) {
 	cfg.API.GRPC.Enable = true
 	cfg.API.GRPCWeb.Enable = true
 	cfg.Storage.StateStore.Enable = true
+	// RPC/full nodes default to the split SS layout (EVM state in its own SS DB).
+	// Scoped here, not baseDefaults: only modes that run the SS store may set it,
+	// and per giga_store_migration.md the split is supported for RPC nodes only
+	// (validator/seed run no SS store; archive resets it below). A fresh node
+	// builds the split on bootstrap; an existing unsplit node adopts it only via a
+	// state-sync, so this default touches new nodes, not a migration path.
+	cfg.Storage.StateStore.EVMSSSplit = true
 	cfg.Storage.StateStore.KeepRecent = 100_000
 	cfg.Storage.StateCommit.AsyncCommitBuffer = 100
 	cfg.Chain.MinRetainBlocks = 100_000
@@ -309,6 +316,9 @@ func applyArchiveOverrides(cfg *SeiConfig) {
 
 	cfg.Storage.PruningStrategy = PruningNothing
 	cfg.Storage.StateStore.KeepRecent = 0
+	// Archive inherits full's overrides but the giga SS split is not supported for
+	// archive nodes yet (giga_store_migration.md: RPC nodes only), so reset it.
+	cfg.Storage.StateStore.EVMSSSplit = false
 	// Only MinRetainBlocks disables receipt pruning at runtime; the next two
 	// are emitted to document intent (see ReceiptStoreConfig).
 	cfg.Chain.MinRetainBlocks = 0
diff --git a/enrichments.go b/enrichments.go
index 5ba6ed2..be23c08 100644
--- a/enrichments.go
+++ b/enrichments.go
@@ -223,6 +223,9 @@ func DefaultEnrichments() map[string][]FieldOption {
 		"storage.state_store.enable": {
 			WithDescription("Enable SeiDB state-store for historical queries."),
 		},
+		"storage.state_store.evm_ss_split": {
+			WithDescription("Store EVM state in the SeiDB state-store (app.toml [state-store] evm-ss-split)."),
+		},
 		"storage.state_store.backend": {
 			WithDescription("State store backend: pebbledb, rocksdb."),
 		},
diff --git a/io_write_test.go b/io_write_test.go
index 9b0c4a8..277fe06 100644
--- a/io_write_test.go
+++ b/io_write_test.go
@@ -107,3 +107,49 @@ func TestWriteConfigToDir_ReceiptStoreUsesRSBackend(t *testing.T) {
 		}
 	}
 }
+
+// TestWriteConfigToDir_EVMSSSplit guards the giga state-store default per mode: only
+// the full/RPC mode renders app.toml [state-store] evm-ss-split=true (the one flag
+// distinguishing a giga SS node from a plain one). validator/seed run no SS store and
+// archive is unsupported, so all three omit the key entirely (omitempty) — leaving
+// their rendered app.toml unchanged. The key is bare evm-ss-split, not ss-prefixed
+// like its siblings, because the binary reads it unprefixed.
+func TestWriteConfigToDir_EVMSSSplit(t *testing.T) {
+	readApp := func(home string) string {
+		b, err := os.ReadFile(filepath.Join(home, configDir, appTomlFile))
+		if err != nil {
+			t.Fatalf("ReadFile app.toml: %v", err)
+		}
+		return string(b)
+	}
+
+	// Mode matrix: full renders the split on; every other mode omits the key.
+	splitModes := map[NodeMode]bool{ModeFull: true}
+	for _, mode := range []NodeMode{ModeValidator, ModeSeed, ModeFull, ModeArchive} {
+		home := t.TempDir()
+		if err := WriteConfigToDir(DefaultForMode(mode), home); err != nil {
+			t.Fatalf("WriteConfigToDir(%s): %v", mode, err)
+		}
+		app := readApp(home)
+		switch {
+		case splitModes[mode]:
+			if !strings.Contains(app, "evm-ss-split = true") {
+				t.Errorf("%s: app.toml must render evm-ss-split = true", mode)
+			}
+			got, err := ReadConfigFromDir(home)
+			if err != nil {
+				t.Fatalf("ReadConfigFromDir(%s): %v", mode, err)
+			}
+			if !got.Storage.StateStore.EVMSSSplit {
+				t.Errorf("%s round-trip: state_store.evm_ss_split got false, want true", mode)
+			}
+		default:
+			if strings.Contains(app, "evm-ss-split") {
+				t.Errorf("%s: must omit evm-ss-split (mode runs no split SS store), but the key is present", mode)
+			}
+		}
+		if strings.Contains(app, "ss-evm-ss-split") {
+			t.Errorf("%s: evm-ss-split must be the bare key, not ss-evm-ss-split — the binary reads it unprefixed", mode)
+		}
+	}
+}
diff --git a/legacy.go b/legacy.go
index dc2f1da..849402d 100644
--- a/legacy.go
+++ b/legacy.go
@@ -268,7 +268,12 @@ type legacyStateCommit struct {
 }
 
 type legacyStateStore struct {
-	Enable               bool   `toml:"ss-enable"`
+	Enable bool `toml:"ss-enable"`
+	// evm-ss-split is bare, NOT ss-prefixed — the binary reads it unprefixed
+	// under [state-store]. Do not add the ss- prefix (cf. rs-backend below).
+	// omitempty so a false value omits the key: an existing (v2) node's app.toml
+	// stays unchanged; only a node with the split on emits evm-ss-split = true.
+	EVMSSSplit           bool   `toml:"evm-ss-split,omitempty"`
 	DBDirectory          string `toml:"ss-db-directory"`
 	Backend              string `toml:"ss-backend"`
 	AsyncWriteBuffer     int    `toml:"ss-async-write-buffer"`
@@ -589,6 +594,7 @@ func (cfg *SeiConfig) toLegacyApp() legacyAppConfig {
 
 		StateStore: legacyStateStore{
 			Enable:               cfg.Storage.StateStore.Enable,
+			EVMSSSplit:           cfg.Storage.StateStore.EVMSSSplit,
 			DBDirectory:          cfg.Storage.StateStore.DBDirectory,
 			Backend:              cfg.Storage.StateStore.Backend,
 			AsyncWriteBuffer:     cfg.Storage.StateStore.AsyncWriteBuffer,
@@ -852,6 +858,7 @@ func fromLegacy(tm legacyTendermintConfig, app legacyAppConfig) *SeiConfig {
 			},
 			StateStore: StateStoreConfig{
 				Enable:               app.StateStore.Enable,
+				EVMSSSplit:           app.StateStore.EVMSSSplit,
 				DBDirectory:          app.StateStore.DBDirectory,
 				Backend:              app.StateStore.Backend,
 				AsyncWriteBuffer:     app.StateStore.AsyncWriteBuffer,
diff --git a/validate.go b/validate.go
index 1fb2426..8ba1ad6 100644
--- a/validate.go
+++ b/validate.go
@@ -278,6 +278,10 @@ func validateStorage(r *ValidationResult, cfg *SeiConfig) {
 		r.addWarning("storage.state_store.backend", fmt.Sprintf(
 			"unusual backend %q; expected pebbledb or rocksdb", ss.Backend))
 	}
+	if ss.EVMSSSplit && !ss.Enable {
+		r.addError("storage.state_store.evm_ss_split",
+			"evm_ss_split requires state_store.enable=true (the split routes EVM state into the state store)")
+	}
 }
 
 func validateEVM(r *ValidationResult, cfg *SeiConfig) {