diff --git a/swh/loader/package/loader.py b/swh/loader/package/loader.py
--- a/swh/loader/package/loader.py
+++ b/swh/loader/package/loader.py
@@ -4,6 +4,7 @@
 # See top-level LICENSE file for more information
 
 import datetime
+import json
 import logging
 import tempfile
 import os
@@ -40,6 +41,7 @@
     OriginVisit,
     OriginVisitStatus,
     MetadataAuthority,
+    MetadataAuthorityType,
     MetadataFetcher,
     MetadataTargetType,
     RawExtrinsicMetadata,
@@ -56,6 +58,16 @@
 logger = logging.getLogger(__name__)
 
 
+SWH_METADATA_AUTHORITY = MetadataAuthority(
+    type=MetadataAuthorityType.REGISTRY,
+    url="https://softwareheritage.org/",
+    metadata={},
+)
+"""Metadata authority for extrinsic metadata generated by Software Heritage.
+Used for metadata on "original artifacts", ie. length, filename, and checksums
+of downloaded archive files."""
+
+
 @attr.s
 class RawExtrinsicMetadataCore:
     """Contains the core of the metadata extracted by a loader, that will be
@@ -175,7 +187,7 @@
             uncompressed_path: Artifact uncompressed path on disk
 
         Returns:
-            SWH data dict
+            Revision object
 
         """
         raise NotImplementedError("build_revision")
@@ -529,17 +541,32 @@
                 # skipping those
                 return None
 
+        metadata = [metadata for (filepath, metadata) in dl_artifacts]
         extra_metadata: Tuple[str, Any] = (
             "original_artifact",
-            [hashes for _, hashes in dl_artifacts],
+            metadata,
         )
+
         if revision.metadata is not None:
             full_metadata = list(revision.metadata.items()) + [extra_metadata]
         else:
             full_metadata = [extra_metadata]
 
+        # TODO: don't add these extrinsic metadata to the revision.
         revision = attr.evolve(revision, metadata=ImmutableDict(full_metadata))
 
+        original_artifact_metadata = RawExtrinsicMetadata(
+            type=MetadataTargetType.REVISION,
+            id=SWHID(object_type="revision", object_id=revision.id),
+            discovery_date=self.visit_date,
+            authority=SWH_METADATA_AUTHORITY,
+            fetcher=self.get_metadata_fetcher(),
+            format="original-artifact-json",
+            metadata=json.dumps(metadata).encode(),
+            origin=self.url,
+        )
+        self._load_metadata_objects([original_artifact_metadata])
+
         logger.debug("Revision: %s", revision)
 
         self.storage.revision_add([revision])
diff --git a/swh/loader/package/tests/test_loader_metadata.py b/swh/loader/package/tests/test_loader_metadata.py
--- a/swh/loader/package/tests/test_loader_metadata.py
+++ b/swh/loader/package/tests/test_loader_metadata.py
@@ -4,7 +4,7 @@
 # See top-level LICENSE file for more information
 
 import datetime
-from typing import Iterator, List, Optional, Sequence, Tuple
+from typing import Iterator, List, Sequence, Tuple
 
 import attr
 
@@ -20,7 +20,10 @@
     MetadataAuthorityType,
     MetadataFetcher,
     MetadataTargetType,
+    Person,
     RawExtrinsicMetadata,
+    Revision,
+    RevisionType,
     Sha1Git,
 )
 from swh.storage import get_storage
@@ -86,8 +89,29 @@
     def get_versions(self) -> Sequence[str]:
         return ["v1.0.0"]
 
-    def _load_revision(self, p_info: BasePackageInfo, origin) -> Optional[Sha1Git]:
-        return REVISION_ID
+    def _load_directory(self, dl_artifacts, tmpdir):
+        class directory:
+            hash = None
+
+        return (None, directory)  # just enough for _load_revision to work
+
+    def download_package(self, p_info: BasePackageInfo, tmpdir: str):
+        return [("path", {"artifact_key": "value", "length": 0})]
+
+    def build_revision(
+        self, p_info: BasePackageInfo, uncompressed_path: str, directory: Sha1Git
+    ):
+        return Revision(
+            id=REVISION_ID,
+            message=b"",
+            author=Person.from_fullname(b""),
+            committer=Person.from_fullname(b""),
+            date=None,
+            committer_date=None,
+            type=RevisionType.TAR,
+            directory=b"foo",
+            synthetic=False,
+        )
 
     def get_metadata_authority(self):
         return attr.evolve(AUTHORITY, metadata={})
@@ -111,6 +135,39 @@
         return [RawExtrinsicMetadataCore(m.format, m.metadata, m.discovery_date)]
 
 
+def test_load_artifact_metadata(swh_config, caplog):
+    storage = get_storage("memory")
+
+    loader = MetadataTestLoader(ORIGIN_URL)
+    loader.storage = storage
+
+    load_status = loader.load()
+    assert load_status == {
+        "status": "eventful",
+        "snapshot_id": FULL_SNAPSHOT_ID,
+    }
+
+    authority = MetadataAuthority(
+        type=MetadataAuthorityType.REGISTRY, url="https://softwareheritage.org/",
+    )
+
+    result = storage.raw_extrinsic_metadata_get(
+        MetadataTargetType.REVISION, REVISION_SWHID, authority,
+    )
+    assert result.next_page_token is None
+    assert len(result.results) == 1
+    assert result.results[0] == RawExtrinsicMetadata(
+        type=MetadataTargetType.REVISION,
+        id=REVISION_SWHID,
+        discovery_date=result.results[0].discovery_date,
+        authority=authority,
+        fetcher=FETCHER,
+        format="original-artifact-json",
+        metadata=b'[{"artifact_key": "value", "length": 0}]',
+        origin=ORIGIN_URL,
+    )
+
+
 def test_load_metadata(swh_config, caplog):
     storage = get_storage("memory")