diff --git a/swh/model/identifiers.py b/swh/model/identifiers.py
--- a/swh/model/identifiers.py
+++ b/swh/model/identifiers.py
@@ -720,7 +720,7 @@
 
     """
     headers = [
-        (b"target_type", metadata["target_type"].encode("ascii")),
+        (b"target_type", metadata["type"].encode("ascii")),
         (b"target", str(metadata["target"]).encode()),
         (b"discovery_date", metadata["discovery_date"].isoformat().encode("ascii")),
         (
diff --git a/swh/model/model.py b/swh/model/model.py
--- a/swh/model/model.py
+++ b/swh/model/model.py
@@ -22,6 +22,7 @@
     directory_identifier,
     normalize_timestamp,
     parse_swhid,
+    raw_extrinsic_metadata_identifier,
     release_identifier,
     revision_identifier,
     snapshot_identifier,
@@ -862,7 +863,7 @@
 
 
 @attr.s(frozen=True, slots=True)
-class RawExtrinsicMetadata(BaseModel):
+class RawExtrinsicMetadata(HashableObject, BaseModel):
     object_type: Final = "raw_extrinsic_metadata"
 
     # target object
@@ -888,6 +889,11 @@
     path = attr.ib(type=Optional[bytes], default=None, validator=type_validator())
     directory = attr.ib(type=Optional[SWHID], default=None, validator=type_validator())
 
+    id = attr.ib(type=Sha1Git, validator=type_validator(), default=b"")
+
+    def compute_hash(self) -> bytes:
+        return hash_to_bytes(raw_extrinsic_metadata_identifier(self.to_dict()))
+
     @target.validator
     def check_target(self, attribute, value):
         if self.type == MetadataTargetType.ORIGIN:
diff --git a/swh/model/tests/test_identifiers.py b/swh/model/tests/test_identifiers.py
--- a/swh/model/tests/test_identifiers.py
+++ b/swh/model/tests/test_identifiers.py
@@ -780,7 +780,7 @@
         }
 
         self.minimal = {
-            "target_type": "content",
+            "type": "content",
             "target": parse_swhid("swh:1:cnt:568aaf43d83b2c3df8067f3bedbb97d83260be6d"),
             "discovery_date": datetime.datetime(
                 2021, 1, 25, 11, 27, 51, tzinfo=datetime.timezone.utc
diff --git a/swh/model/tests/test_model.py b/swh/model/tests/test_model.py
--- a/swh/model/tests/test_model.py
+++ b/swh/model/tests/test_model.py
@@ -784,7 +784,9 @@
 _origin_url = "https://forge.softwareheritage.org/source/swh-model.git"
 _dummy_qualifiers = {"origin": "https://example.com", "lines": "42"}
 _common_metadata_fields = dict(
-    discovery_date=datetime.datetime.now(tz=datetime.timezone.utc),
+    discovery_date=datetime.datetime(
+        2021, 1, 29, 13, 57, 9, tzinfo=datetime.timezone.utc
+    ),
     authority=_metadata_authority,
     fetcher=_metadata_fetcher,
     format="json",
@@ -825,6 +827,7 @@
     assert m.to_dict() == {
         "type": "origin",
         "target": _origin_url,
+        "id": b"\x9b[\x94\xf7\xa7$Dwbc\xf4\xdf\xaf(7G0t-\xd8",
         **common_fields,
     }
     assert RawExtrinsicMetadata.from_dict(m.to_dict()) == m
@@ -837,6 +840,7 @@
     assert m.to_dict() == {
         "type": "content",
         "target": "swh:1:cnt:94a9ed024d3859793618152ea559a168bbcbb5e2",
+        "id": b"\x00\xfd\xe4\x88\xfa\xb5\xac\x7f\x16'\x96\xa8\x10\x9a\xafI\xe9>w\xa7",
         **common_fields,
     }
     assert RawExtrinsicMetadata.from_dict(m.to_dict()) == m