diff --git a/go/vehicle-gateway/internal/realtime/snapshot_writer.go b/go/vehicle-gateway/internal/realtime/snapshot_writer.go
index 68133ce9..1e00c8b4 100644
--- a/go/vehicle-gateway/internal/realtime/snapshot_writer.go
+++ b/go/vehicle-gateway/internal/realtime/snapshot_writer.go
@@ -119,7 +119,7 @@ func (w *SnapshotWriter) Update(ctx context.Context, env envelope.FrameEnvelope)
 	if vin == "" {
 		return nil
 	}
-	if !hasRealtimePayload(env) {
+	if !isRealtimeSnapshotEvent(env) {
 		return nil
 	}
 	plate, err := w.plateForEnvelope(ctx, env)
@@ -365,16 +365,35 @@ func nullableTime(ms int64) any {
 	return time.UnixMilli(ms)
 }
 
-func hasRealtimePayload(env envelope.FrameEnvelope) bool {
-	if len(env.Fields) > 0 {
-		return true
+func isRealtimeSnapshotEvent(env envelope.FrameEnvelope) bool {
+	switch env.Protocol {
+	case envelope.ProtocolGB32960:
+		return env.MessageID == "0x02" && hasGB32960RealtimeDataUnits(env)
+	case envelope.ProtocolJT808:
+		return env.MessageID == "0x0200" && hasLocationFields(env)
+	case envelope.ProtocolYutongMQTT:
+		return len(env.Fields) > 0
+	default:
+		return false
 	}
+}
+
+func hasGB32960RealtimeDataUnits(env envelope.FrameEnvelope) bool {
 	if units, ok := env.Parsed["data_units"].([]any); ok && len(units) > 0 {
 		return true
 	}
+	if units, ok := env.Parsed["data_units"].([]map[string]any); ok && len(units) > 0 {
+		return true
+	}
 	return false
 }
 
+func hasLocationFields(env envelope.FrameEnvelope) bool {
+	_, okLat := numberField(env.Fields, envelope.FieldLatitude)
+	_, okLon := numberField(env.Fields, envelope.FieldLongitude)
+	return okLat && okLon
+}
+
 const realtimeSnapshotTableSQL = `CREATE TABLE IF NOT EXISTS vehicle_realtime_snapshot (
   protocol VARCHAR(32) NOT NULL,
   vin VARCHAR(32) NOT NULL DEFAULT '',
diff --git a/go/vehicle-gateway/internal/realtime/snapshot_writer_test.go b/go/vehicle-gateway/internal/realtime/snapshot_writer_test.go
index 2973bb00..f0e1c7ca 100644
--- a/go/vehicle-gateway/internal/realtime/snapshot_writer_test.go
+++ b/go/vehicle-gateway/internal/realtime/snapshot_writer_test.go
@@ -234,7 +234,7 @@ func TestSnapshotWriterBackfillsPlateFromBindingByVIN(t *testing.T) {
 		VIN:          "VIN001",
 		EventTimeMS:  1782918600000,
 		ReceivedAtMS: 1782918601000,
-		Parsed:       map[string]any{"data_units": []any{}},
+		Parsed:       sampleGB32960RealtimeParsed(),
 		Fields: map[string]any{
 			envelope.FieldLatitude:  30.590151,
 			envelope.FieldLongitude: 121.069881,
@@ -289,6 +289,7 @@ func TestSnapshotWriterCachesBindingPlateByVIN(t *testing.T) {
 		VIN:          "VIN001",
 		EventTimeMS:  1782918600000,
 		ReceivedAtMS: 1782918601000,
+		Parsed:       sampleGB32960RealtimeParsed(),
 		Fields: map[string]any{
 			envelope.FieldLatitude:  30.590151,
 			envelope.FieldLongitude: 121.069881,
@@ -355,7 +356,7 @@ func TestSnapshotWriterIgnoresMissingBindingPlate(t *testing.T) {
 		VIN:          "VIN001",
 		EventTimeMS:  1782918600000,
 		ReceivedAtMS: 1782918601000,
-		Parsed:       map[string]any{"data_units": []any{}},
+		Parsed:       sampleGB32960RealtimeParsed(),
 		Fields:       map[string]any{envelope.FieldSOCPercent: 90},
 	}); err != nil {
 		t.Fatalf("Update() error = %v", err)
@@ -375,7 +376,7 @@ func TestSnapshotWriterReturnsUnexpectedPlateLookupError(t *testing.T) {
 		VIN:          "VIN001",
 		EventTimeMS:  1782918600000,
 		ReceivedAtMS: 1782918601000,
-		Parsed:       map[string]any{"data_units": []any{}},
+		Parsed:       sampleGB32960RealtimeParsed(),
 		Fields:       map[string]any{envelope.FieldSOCPercent: 90},
 	})
 	if err == nil || !strings.Contains(err.Error(), "db down") {
@@ -445,6 +446,78 @@ func TestSnapshotWriterSkipsGB32960HeartbeatWithoutRealtimePayload(t *testing.T)
 	}
 }
 
+func TestSnapshotWriterSkipsGB32960NonRealtimeEvenWithConnectionMetadata(t *testing.T) {
+	exec := &recordingSnapshotExec{}
+	writer := NewSnapshotWriter(exec)
+
+	if err := writer.Update(context.Background(), envelope.FrameEnvelope{
+		Protocol:     envelope.ProtocolGB32960,
+		MessageID:    "0x07",
+		VIN:          "ABCDE600000000009",
+		EventTimeMS:  1782918600000,
+		ReceivedAtMS: 1782918601000,
+		Parsed: map[string]any{
+			"header":        map[string]any{"command": "0x07", "vin": "ABCDE600000000009"},
+			"platform_name": "YueJin",
+		},
+		Fields: map[string]any{
+			"platform_account": "YueJin",
+		},
+	}); err != nil {
+		t.Fatalf("Update() error = %v", err)
+	}
+	if len(exec.calls) != 0 {
+		t.Fatalf("exec calls = %d, want 0", len(exec.calls))
+	}
+}
+
+func TestSnapshotWriterSkipsJT808NonLocationEvenWithIdentityFields(t *testing.T) {
+	exec := &recordingSnapshotExec{}
+	writer := NewSnapshotWriter(exec)
+
+	if err := writer.Update(context.Background(), envelope.FrameEnvelope{
+		Protocol:     envelope.ProtocolJT808,
+		MessageID:    "0x0100",
+		VIN:          "VIN001",
+		Plate:        "粤A12345",
+		EventTimeMS:  1782918600000,
+		ReceivedAtMS: 1782918601000,
+		Parsed: map[string]any{
+			"registration": map[string]any{"plate": "粤A12345"},
+		},
+		Fields: map[string]any{
+			"plate": "粤A12345",
+		},
+	}); err != nil {
+		t.Fatalf("Update() error = %v", err)
+	}
+	if len(exec.calls) != 0 {
+		t.Fatalf("exec calls = %d, want 0", len(exec.calls))
+	}
+}
+
+func TestSnapshotWriterSkipsMQTTWithoutActualDataFields(t *testing.T) {
+	exec := &recordingSnapshotExec{}
+	writer := NewSnapshotWriter(exec)
+
+	if err := writer.Update(context.Background(), envelope.FrameEnvelope{
+		Protocol:     envelope.ProtocolYutongMQTT,
+		MessageID:    "MQTT",
+		VIN:          "VIN001",
+		EventTimeMS:  1782918600000,
+		ReceivedAtMS: 1782918601000,
+		Parsed: map[string]any{
+			"topic": "/vehicle/VIN001/state",
+			"data":  map[string]any{},
+		},
+	}); err != nil {
+		t.Fatalf("Update() error = %v", err)
+	}
+	if len(exec.calls) != 0 {
+		t.Fatalf("exec calls = %d, want 0", len(exec.calls))
+	}
+}
+
 func TestSnapshotWriterSkipsEmptyDataUnitsWithoutCoreFields(t *testing.T) {
 	exec := &recordingSnapshotExec{}
 	writer := NewSnapshotWriter(exec)
@@ -468,6 +541,14 @@ type recordingSnapshotExec struct {
 	calls []snapshotExecCall
 }
 
+func sampleGB32960RealtimeParsed() map[string]any {
+	return map[string]any{
+		"data_units": []any{
+			map[string]any{"type": "0x01", "name": "vehicle", "value": map[string]any{"soc_percent": 90}},
+		},
+	}
+}
+
 type snapshotExecCall struct {
 	query string
 	args  []any