diff --git a/modules/core/ingest-facts/src/main/java/com/lingniu/ingest/facts/DecodedFact.java b/modules/core/ingest-facts/src/main/java/com/lingniu/ingest/facts/DecodedFact.java
new file mode 100644
index 00000000..f155d039
--- /dev/null
+++ b/modules/core/ingest-facts/src/main/java/com/lingniu/ingest/facts/DecodedFact.java
@@ -0,0 +1,215 @@
+package com.lingniu.ingest.facts;
+
+import com.lingniu.ingest.api.ProtocolId;
+
+import java.time.Instant;
+import java.util.Map;
+
+public sealed interface DecodedFact
+        permits DecodedFact.Location,
+                DecodedFact.Realtime,
+                DecodedFact.Alarm,
+                DecodedFact.Session,
+                DecodedFact.Register,
+                DecodedFact.Extension {
+
+    String factId();
+    String frameId();
+    ProtocolId protocol();
+    String vehicleKey();
+    String vin();
+    String phone();
+    Instant eventTime();
+    Instant receivedAt();
+    String rawUri();
+    Map<String, String> metadata();
+
+    record Location(
+            String factId,
+            String frameId,
+            ProtocolId protocol,
+            String vehicleKey,
+            String vin,
+            String phone,
+            Instant eventTime,
+            Instant receivedAt,
+            String rawUri,
+            Map<String, String> metadata,
+            Double longitude,
+            Double latitude,
+            Double altitudeM,
+            Double speedKmh,
+            Double directionDeg,
+            Long alarmFlag,
+            Long statusFlag,
+            Double totalMileageKm
+    ) implements DecodedFact {
+        public Location {
+            BaseFields.validate(factId, frameId, protocol, vehicleKey, eventTime, receivedAt, rawUri);
+            vin = BaseFields.clean(vin);
+            phone = BaseFields.clean(phone);
+            metadata = BaseFields.metadata(metadata);
+        }
+    }
+
+    record Realtime(
+            String factId,
+            String frameId,
+            ProtocolId protocol,
+            String vehicleKey,
+            String vin,
+            String phone,
+            Instant eventTime,
+            Instant receivedAt,
+            String rawUri,
+            Map<String, String> metadata,
+            Map<String, String> fields
+    ) implements DecodedFact {
+        public Realtime {
+            BaseFields.validate(factId, frameId, protocol, vehicleKey, eventTime, receivedAt, rawUri);
+            vin = BaseFields.clean(vin);
+            phone = BaseFields.clean(phone);
+            metadata = BaseFields.metadata(metadata);
+            fields = fields == null ? Map.of() : Map.copyOf(fields);
+        }
+    }
+
+    record Alarm(
+            String factId,
+            String frameId,
+            ProtocolId protocol,
+            String vehicleKey,
+            String vin,
+            String phone,
+            Instant eventTime,
+            Instant receivedAt,
+            String rawUri,
+            Map<String, String> metadata,
+            String alarmLevel,
+            Long alarmCode,
+            String alarmName,
+            Map<String, String> fields
+    ) implements DecodedFact {
+        public Alarm {
+            BaseFields.validate(factId, frameId, protocol, vehicleKey, eventTime, receivedAt, rawUri);
+            vin = BaseFields.clean(vin);
+            phone = BaseFields.clean(phone);
+            alarmLevel = BaseFields.clean(alarmLevel);
+            alarmName = BaseFields.clean(alarmName);
+            metadata = BaseFields.metadata(metadata);
+            fields = fields == null ? Map.of() : Map.copyOf(fields);
+        }
+    }
+
+    record Session(
+            String factId,
+            String frameId,
+            ProtocolId protocol,
+            String vehicleKey,
+            String vin,
+            String phone,
+            Instant eventTime,
+            Instant receivedAt,
+            String rawUri,
+            Map<String, String> metadata,
+            String sessionType,
+            Integer resultCode,
+            Map<String, String> fields
+    ) implements DecodedFact {
+        public Session {
+            BaseFields.validate(factId, frameId, protocol, vehicleKey, eventTime, receivedAt, rawUri);
+            vin = BaseFields.clean(vin);
+            phone = BaseFields.clean(phone);
+            sessionType = BaseFields.clean(sessionType);
+            metadata = BaseFields.metadata(metadata);
+            fields = fields == null ? Map.of() : Map.copyOf(fields);
+        }
+    }
+
+    record Register(
+            String factId,
+            String frameId,
+            ProtocolId protocol,
+            String vehicleKey,
+            String vin,
+            String phone,
+            Instant eventTime,
+            Instant receivedAt,
+            String rawUri,
+            Map<String, String> metadata,
+            Map<String, String> registrationFields
+    ) implements DecodedFact {
+        public Register {
+            BaseFields.validate(factId, frameId, protocol, vehicleKey, eventTime, receivedAt, rawUri);
+            vin = BaseFields.clean(vin);
+            phone = BaseFields.clean(phone);
+            metadata = BaseFields.metadata(metadata);
+            registrationFields = registrationFields == null ? Map.of() : Map.copyOf(registrationFields);
+        }
+    }
+
+    record Extension(
+            String factId,
+            String frameId,
+            ProtocolId protocol,
+            String vehicleKey,
+            String vin,
+            String phone,
+            Instant eventTime,
+            Instant receivedAt,
+            String rawUri,
+            Map<String, String> metadata,
+            String extensionType,
+            Map<String, String> fields
+    ) implements DecodedFact {
+        public Extension {
+            BaseFields.validate(factId, frameId, protocol, vehicleKey, eventTime, receivedAt, rawUri);
+            vin = BaseFields.clean(vin);
+            phone = BaseFields.clean(phone);
+            extensionType = BaseFields.clean(extensionType);
+            metadata = BaseFields.metadata(metadata);
+            fields = fields == null ? Map.of() : Map.copyOf(fields);
+        }
+    }
+
+    final class BaseFields {
+        private BaseFields() {
+        }
+
+        static void validate(String factId,
+                             String frameId,
+                             ProtocolId protocol,
+                             String vehicleKey,
+                             Instant eventTime,
+                             Instant receivedAt,
+                             String rawUri) {
+            required(factId, "factId");
+            required(frameId, "frameId");
+            if (protocol == null) {
+                throw new IllegalArgumentException("protocol must not be null");
+            }
+            required(vehicleKey, "vehicleKey");
+            if (eventTime == null) {
+                throw new IllegalArgumentException("eventTime must not be null");
+            }
+            if (receivedAt == null) {
+                throw new IllegalArgumentException("receivedAt must not be null");
+            }
+            required(rawUri, "rawUri");
+        }
+
+        static String clean(String value) {
+            return value == null ? "" : value.trim();
+        }
+
+        static Map<String, String> metadata(Map<String, String> metadata) {
+            return metadata == null ? Map.of() : Map.copyOf(metadata);
+        }
+
+        private static void required(String value, String field) {
+            if (clean(value).isBlank()) {
+                throw new IllegalArgumentException(field + " must not be blank");
+            }
+        }
+    }
+}
diff --git a/modules/core/ingest-facts/src/test/java/com/lingniu/ingest/facts/DecodedFactTest.java b/modules/core/ingest-facts/src/test/java/com/lingniu/ingest/facts/DecodedFactTest.java
new file mode 100644
index 00000000..06f71891
--- /dev/null
+++ b/modules/core/ingest-facts/src/test/java/com/lingniu/ingest/facts/DecodedFactTest.java
@@ -0,0 +1,39 @@
+package com.lingniu.ingest.facts;
+
+import com.lingniu.ingest.api.ProtocolId;
+import org.junit.jupiter.api.Test;
+
+import java.time.Instant;
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class DecodedFactTest {
+
+    @Test
+    void locationFactCarriesRawReferenceAndMetadata() {
+        DecodedFact.Location location = new DecodedFact.Location(
+                "fact-1",
+                "frame-1",
+                ProtocolId.JT808,
+                "jt808:013912345678",
+                "",
+                "013912345678",
+                Instant.parse("2026-06-29T00:00:00Z"),
+                Instant.parse("2026-06-29T00:00:01Z"),
+                "archive://jt808/frame-1.bin",
+                Map.of("messageId", "0x0200"),
+                120.123456,
+                30.123456,
+                10.0,
+                42.0,
+                180.0,
+                0L,
+                2L,
+                1000.5);
+
+        assertThat(location.factId()).isEqualTo("fact-1");
+        assertThat(location.rawUri()).isEqualTo("archive://jt808/frame-1.bin");
+        assertThat(location.metadata()).containsEntry("messageId", "0x0200");
+    }
+}