diff --git a/swh/loader/package/deposit/loader.py b/swh/loader/package/deposit/loader.py
--- a/swh/loader/package/deposit/loader.py
+++ b/swh/loader/package/deposit/loader.py
@@ -17,6 +17,11 @@
     RevisionType,
     TimestampWithTimezone,
     Sha1Git,
+    MetadataAuthority,
+    MetadataAuthorityType,
+    MetadataFetcher,
+    MetadataTargetType,
+    RawExtrinsicMetadata,
 )
 from swh.loader.package.loader import PackageLoader
 from swh.loader.package.utils import download
@@ -126,33 +131,37 @@
             logger.debug("origin_metadata: %s", origin_metadata)
 
             provider = origin_metadata["provider"]
-            authority = {
-                "type": provider["provider_type"],
-                "url": provider["provider_url"],
-                "metadata": {
+            assert provider["provider_type"] == "deposit_client"
+            authority = MetadataAuthority(
+                type=MetadataAuthorityType.DEPOSIT,
+                url=provider["provider_url"],
+                metadata={
                     "name": provider["provider_name"],
                     **(provider["metadata"] or {}),
                 },
-            }
-            self.storage.metadata_authority_add(**authority)
+            )
+            self.storage.metadata_authority_add([authority])
 
             tool = origin_metadata["tool"]
-            fetcher = {
-                "name": tool["name"],
-                "version": tool["version"],
-                "metadata": tool["configuration"],
-            }
-            self.storage.metadata_fetcher_add(**fetcher)
-
-            metadata = origin_metadata["metadata"]
-            format = "sword-v2-atom-codemeta-v2-in-json"
-            self.storage.origin_metadata_add(
-                self.url,
-                self.visit_date,
-                {"type": authority["type"], "url": authority["url"]},
-                {"name": fetcher["name"], "version": fetcher["version"]},
-                format,
-                json.dumps(metadata).encode(),
+            fetcher = MetadataFetcher(
+                name=tool["name"],
+                version=tool["version"],
+                metadata=tool["configuration"],
+            )
+            self.storage.metadata_fetcher_add([fetcher])
+
+            self.storage.object_metadata_add(
+                [
+                    RawExtrinsicMetadata(
+                        type=MetadataTargetType.ORIGIN,
+                        id=self.url,
+                        discovery_date=self.visit_date,
+                        authority=authority,
+                        fetcher=fetcher,
+                        format="sword-v2-atom-codemeta-v2-in-json",
+                        metadata=json.dumps(origin_metadata["metadata"]).encode(),
+                    )
+                ]
             )
 
         # Update deposit status
diff --git a/swh/loader/package/deposit/tests/test_deposit.py b/swh/loader/package/deposit/tests/test_deposit.py
--- a/swh/loader/package/deposit/tests/test_deposit.py
+++ b/swh/loader/package/deposit/tests/test_deposit.py
@@ -9,7 +9,16 @@
 import pytest
 
 from swh.model.hashutil import hash_to_bytes, hash_to_hex
-from swh.model.model import Snapshot, SnapshotBranch, TargetType
+from swh.model.model import (
+    Snapshot,
+    SnapshotBranch,
+    TargetType,
+    MetadataAuthority,
+    MetadataAuthorityType,
+    MetadataFetcher,
+    MetadataTargetType,
+    RawExtrinsicMetadata,
+)
 from swh.loader.package.deposit.loader import DepositLoader
 
 from swh.loader.package.tests.common import check_metadata_paths
@@ -187,25 +196,24 @@
 
     # check metadata
 
-    fetcher = {
-        "name": "swh-deposit",
-        "version": "0.0.1",
-    }
+    fetcher = MetadataFetcher(name="swh-deposit", version="0.0.1",)
 
-    authority = {
-        "type": "deposit_client",
-        "url": "https://hal-test.archives-ouvertes.fr/",
-    }
+    authority = MetadataAuthority(
+        type=MetadataAuthorityType.DEPOSIT,
+        url="https://hal-test.archives-ouvertes.fr/",
+    )
 
-    orig_meta = loader.storage.origin_metadata_get(url, authority)
+    orig_meta = loader.storage.object_metadata_get(
+        MetadataTargetType.ORIGIN, url, authority
+    )
     assert orig_meta is not None
     assert isinstance(orig_meta, dict)
     assert len(orig_meta["results"]) == 1
     assert orig_meta["next_page_token"] is None
     orig_meta0 = orig_meta["results"][0]
 
-    assert orig_meta0["authority"] == authority
-    assert orig_meta0["fetcher"] == fetcher
+    assert orig_meta0.authority == authority
+    assert orig_meta0.fetcher == fetcher
 
     # Retrieve the information for deposit status update query to the deposit
     urls = [
@@ -311,18 +319,17 @@
         ],
     }
 
-    fetcher = {
-        "name": "swh-deposit",
-        "version": "0.0.1",
-    }
+    fetcher = MetadataFetcher(name="swh-deposit", version="0.0.1",)
 
-    authority = {
-        "type": "deposit_client",
-        "url": "https://hal-test.archives-ouvertes.fr/",
-    }
+    authority = MetadataAuthority(
+        type=MetadataAuthorityType.DEPOSIT,
+        url="https://hal-test.archives-ouvertes.fr/",
+    )
 
     # Check the metadata swh side
-    orig_meta = loader.storage.origin_metadata_get(url, authority)
+    orig_meta = loader.storage.object_metadata_get(
+        MetadataTargetType.ORIGIN, url, authority
+    )
     assert orig_meta is not None
     assert isinstance(orig_meta, dict)
     assert len(orig_meta["results"]) == 1
@@ -331,12 +338,12 @@
     assert len(orig_meta["results"]) == 1
 
     orig_meta0 = orig_meta["results"][0]
-    # dynamic, a pain to display and not that interesting
-    orig_meta0.pop("discovery_date")
 
-    assert orig_meta0 == {
-        "origin_url": "https://hal-test.archives-ouvertes.fr/some-external-id",
-        "metadata": json.dumps(
+    assert orig_meta0 == RawExtrinsicMetadata(
+        type=MetadataTargetType.ORIGIN,
+        id="https://hal-test.archives-ouvertes.fr/some-external-id",
+        discovery_date=orig_meta0.discovery_date,
+        metadata=json.dumps(
             {
                 "@xmlns": ["http://www.w3.org/2005/Atom"],
                 "author": ["some awesome author", "another one", "no one"],
@@ -346,10 +353,10 @@
                 "url": "https://hal-test.archives-ouvertes.fr/some-external-id",
             }
         ).encode(),
-        "format": "sword-v2-atom-codemeta-v2-in-json",
-        "authority": authority,
-        "fetcher": fetcher,
-    }
+        format="sword-v2-atom-codemeta-v2-in-json",
+        authority=authority,
+        fetcher=fetcher,
+    )
 
     # Retrieve the information for deposit status update query to the deposit
     urls = [