diff --git a/conftest.py b/conftest.py
--- a/conftest.py
+++ b/conftest.py
@@ -19,7 +19,6 @@
         'storage': {
             'cls': 'pipeline',
             'steps': [
-                {'cls': 'validate'},
                 {'cls': 'retry'},
                 {'cls': 'filter'},
                 {'cls': 'buffer'},
diff --git a/requirements-swh.txt b/requirements-swh.txt
--- a/requirements-swh.txt
+++ b/requirements-swh.txt
@@ -1,4 +1,4 @@
 swh.core >= 0.0.75
-swh.model >= 0.0.54
+swh.model >= 0.0.57
 swh.scheduler
 swh.storage >= 0.0.163
diff --git a/swh/loader/core/tests/test_converters.py b/swh/loader/core/tests/test_converters.py
--- a/swh/loader/core/tests/test_converters.py
+++ b/swh/loader/core/tests/test_converters.py
@@ -31,8 +31,7 @@
     data = b'temp file for testing content storage conversion'
     tmpfile = tmpfile_with_content(tmpdir, data)
 
-    obj = from_disk.Content.from_file(path=os.fsdecode(tmpfile),
-                                      save_path=True).get_data()
+    obj = from_disk.Content.from_file(path=os.fsdecode(tmpfile)).get_data()
 
     expected_content = obj.copy()
     expected_content['data'] = data
diff --git a/swh/loader/package/archive/loader.py b/swh/loader/package/archive/loader.py
--- a/swh/loader/package/archive/loader.py
+++ b/swh/loader/package/archive/loader.py
@@ -101,8 +101,8 @@
                 return rev_id
         return None
 
-    def build_revision(self, a_metadata: Mapping[str, Any],
-                       uncompressed_path: str) -> Dict:
+    def build_revision_data(self, a_metadata: Mapping[str, Any],
+                            uncompressed_path: str) -> Dict:
         time = a_metadata['time']  # assume it's a timestamp
         if isinstance(time, str):  # otherwise, assume it's a parsable date
             time = iso8601.parse_date(time)
diff --git a/swh/loader/package/cran/loader.py b/swh/loader/package/cran/loader.py
--- a/swh/loader/package/cran/loader.py
+++ b/swh/loader/package/cran/loader.py
@@ -83,7 +83,7 @@
                 return rev_id
         return None
 
-    def build_revision(
+    def build_revision_data(
             self, a_metadata: Mapping[str, Any],
             uncompressed_path: str) -> Dict[str, Any]:
         # a_metadata is empty
diff --git a/swh/loader/package/debian/loader.py b/swh/loader/package/debian/loader.py
--- a/swh/loader/package/debian/loader.py
+++ b/swh/loader/package/debian/loader.py
@@ -119,8 +119,8 @@
         logger.debug('dl_artifacts: %s', dl_artifacts)
         return extract_package(dl_artifacts, dest=dest)
 
-    def build_revision(self, a_metadata: Mapping[str, Any],
-                       uncompressed_path: str) -> Dict:
+    def build_revision_data(self, a_metadata: Mapping[str, Any],
+                            uncompressed_path: str) -> Dict:
         dsc_url, dsc_name = dsc_information(a_metadata)
         if not dsc_name:
             raise ValueError(
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
@@ -68,7 +68,7 @@
         return [self.client.archive_get(
             self.deposit_id, tmpdir, p_info['filename'])]
 
-    def build_revision(
+    def build_revision_data(
             self, a_metadata: Dict, uncompressed_path: str) -> Dict:
         revision = a_metadata.pop('revision')
         metadata = {
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
@@ -14,16 +14,21 @@
 
 from swh.core.tarball import uncompress
 from swh.core.config import SWHConfig
-from swh.model.from_disk import Directory
+from swh.model import from_disk
 from swh.model.hashutil import hash_to_hex
 from swh.model.identifiers import (
     revision_identifier, snapshot_identifier, identifier_to_bytes
 )
-from swh.model.model import Sha1Git
+from swh.model.model import (
+    BaseModel, Sha1Git,
+    Content, SkippedContent, Directory,
+    Revision,
+    TargetType, Snapshot,
+    Origin
+)
 from swh.storage import get_storage
 from swh.storage.algos.snapshot import snapshot_get_all_branches
 
-from swh.loader.core.converters import prepare_contents
 from swh.loader.package.utils import download
 
 
@@ -95,7 +100,7 @@
         """
         yield from {}
 
-    def build_revision(
+    def build_revision_data(
             self, a_metadata: Dict, uncompressed_path: str) -> Dict:
         """Build the revision dict from the archive metadata (extrinsic
         artifact metadata) and the intrinsic metadata.
@@ -119,19 +124,20 @@
         """
         return ''
 
-    def last_snapshot(self) -> Optional[Dict]:
+    def last_snapshot(self) -> Optional[Snapshot]:
         """Retrieve the last snapshot
 
         """
         snapshot = None
         visit = self.storage.origin_visit_get_latest(
             self.url, require_snapshot=True)
-        if visit:
-            snapshot = snapshot_get_all_branches(
-                self.storage, visit['snapshot'])
+        if visit and visit.get('snapshot'):
+            snapshot = Snapshot.from_dict(snapshot_get_all_branches(
+                    self.storage, visit['snapshot']))
         return snapshot
 
-    def known_artifacts(self, snapshot: Optional[Dict]) -> Dict:
+    def known_artifacts(
+            self, snapshot: Optional[Snapshot]) -> Dict[Sha1Git, BaseModel]:
         """Retrieve the known releases/artifact for the origin.
 
         Args
@@ -141,13 +147,13 @@
             Dict of keys revision id (bytes), values a metadata Dict.
 
         """
-        if not snapshot or 'branches' not in snapshot:
+        if not snapshot:
             return {}
 
         # retrieve only revisions (e.g the alias we do not want here)
-        revs = [rev['target']
-                for rev in snapshot['branches'].values()
-                if rev and rev['target_type'] == 'revision']
+        revs = [rev.target
+                for rev in snapshot.branches.values()
+                if rev and rev.target_type == TargetType.REVISION]
         known_revisions = self.storage.revision_get(revs)
 
         ret = {}
@@ -263,16 +269,15 @@
         snapshot = None
 
         # Prepare origin and origin_visit
-        origin = {'url': self.url}
+        origin = Origin(url=self.url)
         try:
             self.storage.origin_add_one(origin)
             visit_id = self.storage.origin_visit_add(
                 origin=self.url,
                 date=self.visit_date,
                 type=self.visit_type)['visit']
-        except Exception as e:
-            logger.error(
-                'Failed to create origin/origin_visit. Reason: %s', e)
+        except Exception:
+            logger.exception('Failed to create origin/origin_visit:')
             return {'status': 'failed'}
 
         try:
@@ -327,13 +332,15 @@
                         'target': target,
                     }
 
-            snapshot = {
+            snapshot_data = {
                 'branches': branches
             }
-            logger.debug('snapshot: %s', snapshot)
+            logger.debug('snapshot: %s', snapshot_data)
 
-            snapshot['id'] = identifier_to_bytes(
-                snapshot_identifier(snapshot))
+            snapshot_data['id'] = identifier_to_bytes(
+                snapshot_identifier(snapshot_data))
+
+            snapshot = Snapshot.from_dict(snapshot_data)
 
             logger.debug('snapshot: %s', snapshot)
             self.storage.snapshot_add([snapshot])
@@ -346,12 +353,12 @@
         finally:
             self.storage.origin_visit_update(
                 origin=self.url, visit_id=visit_id, status=status_visit,
-                snapshot=snapshot and snapshot['id'])
+                snapshot=snapshot and snapshot.id)
         result = {
             'status': status_load,
         }  # type: Dict[str, Any]
         if snapshot:
-            result['snapshot_id'] = hash_to_hex(snapshot['id'])
+            result['snapshot_id'] = hash_to_hex(snapshot.id)
         return result
 
     def _load_revision(self, p_info, origin) -> Tuple[Optional[Sha1Git], bool]:
@@ -373,51 +380,64 @@
             uncompressed_path = self.uncompress(dl_artifacts, dest=tmpdir)
             logger.debug('uncompressed_path: %s', uncompressed_path)
 
-            directory = Directory.from_disk(
+            directory = from_disk.Directory.from_disk(
                 path=uncompressed_path.encode('utf-8'),
-                data=True)  # noqa
-            # FIXME: Try not to load the full raw content in
-            # memory
-            objects = directory.collect()
-
-            contents, skipped_contents = prepare_contents(
-                objects.get('content', {}).values(),
-                max_content_size=self.max_content_size,
-                origin_url=origin['url'])
-            self.storage.skipped_content_add(skipped_contents)
+                max_content_length=self.max_content_size)
+
+            contents: List[Content] = []
+            skipped_contents: List[SkippedContent] = []
+            directories: List[Directory] = []
+
+            for obj in directory.iter_tree():
+                obj = obj.to_model()
+                if isinstance(obj, Content):
+                    # FIXME: read the data from disk later (when the
+                    # storage buffer is flushed).
+                    obj = obj.with_data()
+                    contents.append(obj)
+                elif isinstance(obj, SkippedContent):
+                    skipped_contents.append(obj)
+                elif isinstance(obj, Directory):
+                    directories.append(obj)
+                else:
+                    raise TypeError(
+                        f'Unexpected content type from disk: {obj}')
+
             logger.debug('Number of skipped contents: %s',
                          len(skipped_contents))
-            self.storage.content_add(contents)
+            self.storage.skipped_content_add(skipped_contents)
             logger.debug('Number of contents: %s', len(contents))
+            self.storage.content_add(contents)
 
-            directories = list(
-                objects.get('directory', {}).values())
             logger.debug('Number of directories: %s', len(directories))
             self.storage.directory_add(directories)
 
             # FIXME: This should be release. cf. D409
-            revision = self.build_revision(p_info['raw'], uncompressed_path)
-            if not revision:
+            revision_data = self.build_revision_data(
+                p_info['raw'], uncompressed_path)
+            if not revision_data:
                 # Some artifacts are missing intrinsic metadata
                 # skipping those
                 return (None, True)
 
-            revision.update({
+            revision_data.update({
                 'synthetic': True,
                 'directory': directory.hash,
             })
 
-        revision['metadata'].update({
+        revision_data['metadata'].update({
             'original_artifact': [
                 hashes for _, hashes in dl_artifacts
             ],
         })
 
-        revision['id'] = identifier_to_bytes(
-            revision_identifier(revision))
+        revision_data['id'] = identifier_to_bytes(
+            revision_identifier(revision_data))
+
+        revision = Revision.from_dict(revision_data)
 
         logger.debug('Revision: %s', revision)
 
         self.storage.revision_add([revision])
 
-        return (revision['id'], True)
+        return (revision.id, True)
diff --git a/swh/loader/package/npm/loader.py b/swh/loader/package/npm/loader.py
--- a/swh/loader/package/npm/loader.py
+++ b/swh/loader/package/npm/loader.py
@@ -74,7 +74,7 @@
             -> Optional[bytes]:
         return artifact_to_revision_id(known_artifacts, artifact_metadata)
 
-    def build_revision(
+    def build_revision_data(
             self, a_metadata: Dict, uncompressed_path: str) -> Dict:
         i_metadata = extract_intrinsic_metadata(uncompressed_path)
         if not i_metadata:
diff --git a/swh/loader/package/pypi/loader.py b/swh/loader/package/pypi/loader.py
--- a/swh/loader/package/pypi/loader.py
+++ b/swh/loader/package/pypi/loader.py
@@ -71,7 +71,7 @@
             -> Optional[bytes]:
         return artifact_to_revision_id(known_artifacts, artifact_metadata)
 
-    def build_revision(
+    def build_revision_data(
             self, a_metadata: Dict, uncompressed_path: str) -> Dict:
         i_metadata = extract_intrinsic_metadata(uncompressed_path)
         if not i_metadata:
diff --git a/swh/loader/package/tests/test_common.py b/swh/loader/package/tests/test_common.py
--- a/swh/loader/package/tests/test_common.py
+++ b/swh/loader/package/tests/test_common.py
@@ -6,6 +6,7 @@
 import pytest
 
 from swh.model.hashutil import hash_to_bytes
+from swh.model.model import Snapshot, SnapshotBranch, TargetType
 from swh.loader.package.tests.common import (
     decode_target, check_snapshot, check_metadata, check_metadata_paths
 )
@@ -17,9 +18,6 @@
 storage_config = {
     'cls': 'pipeline',
     'steps': [
-        {
-            'cls': 'validate',
-        },
         {
             'cls': 'memory',
         }
@@ -57,15 +55,15 @@
     storage = get_storage(**storage_config)
 
     snap_id = '2498dbf535f882bc7f9a18fb16c9ad27fda7bab7'
-    snapshot = {
-        'id': hash_to_bytes(snap_id),
-        'branches': {
-            b'master': {
-                'target': hash_to_bytes(hash_hex),
-                'target_type': 'revision',
-            },
+    snapshot = Snapshot(
+        id=hash_to_bytes(snap_id),
+        branches={
+            b'master': SnapshotBranch(
+                target=hash_to_bytes(hash_hex),
+                target_type=TargetType.REVISION,
+            ),
         },
-    }
+    )
 
     s = storage.snapshot_add([snapshot])
     assert s == {
@@ -87,15 +85,15 @@
 def test_check_snapshot_failure():
     storage = get_storage(**storage_config)
 
-    snapshot = {
-        'id': hash_to_bytes('2498dbf535f882bc7f9a18fb16c9ad27fda7bab7'),
-        'branches': {
-            b'master': {
-                'target': hash_to_bytes(hash_hex),
-                'target_type': 'revision',
-            },
+    snapshot = Snapshot(
+        id=hash_to_bytes('2498dbf535f882bc7f9a18fb16c9ad27fda7bab7'),
+        branches={
+            b'master': SnapshotBranch(
+                target=hash_to_bytes(hash_hex),
+                target_type=TargetType.REVISION,
+            ),
         },
-    }
+    )
 
     s = storage.snapshot_add([snapshot])
     assert s == {