diff --git a/swh/storage/cassandra/storage.py b/swh/storage/cassandra/storage.py
--- a/swh/storage/cassandra/storage.py
+++ b/swh/storage/cassandra/storage.py
@@ -19,12 +19,7 @@
 )
 from swh.objstorage import get_objstorage
 from swh.objstorage.exc import ObjNotFoundError
-try:
-    from swh.journal.writer import get_journal_writer
-except ImportError:
-    get_journal_writer = None  # type: ignore
-    # mypy limitation, see https://github.com/python/mypy/issues/1153
-
+from swh.storage.writer import JournalWriter
 
 from .. import HashCollision
 from ..exc import StorageArgumentException
@@ -50,11 +45,7 @@
         self._cql_runner = CqlRunner(hosts, keyspace, port)
 
         self.objstorage = get_objstorage(**objstorage)
-
-        if journal_writer:
-            self.journal_writer = get_journal_writer(**journal_writer)
-        else:
-            self.journal_writer = None
+        self.journal_writer = JournalWriter(journal_writer)
 
     def check_config(self, *, check_write):
         self._cql_runner.check_read()
@@ -71,12 +62,7 @@
         contents = [c for c in contents
                     if not self._cql_runner.content_get_from_pk(c.to_dict())]
 
-        if self.journal_writer:
-            for content in contents:
-                content = content.to_dict()
-                if 'data' in content:
-                    del content['data']
-                self.journal_writer.write_addition('content', content)
+        self.journal_writer.content_add(c.to_dict() for c in contents)
 
         count_contents = 0
         count_content_added = 0
@@ -275,12 +261,7 @@
             c for c in contents
             if not self._cql_runner.skipped_content_get_from_pk(c.to_dict())]
 
-        if self.journal_writer:
-            for content in contents:
-                content = content.to_dict()
-                if 'data' in content:
-                    del content['data']
-                self.journal_writer.write_addition('content', content)
+        self.journal_writer.skipped_content_add(c.to_dict() for c in contents)
 
         for content in contents:
             # Add to index tables
@@ -314,8 +295,7 @@
         missing = self.directory_missing([dir_['id'] for dir_ in directories])
         directories = [dir_ for dir_ in directories if dir_['id'] in missing]
 
-        if self.journal_writer:
-            self.journal_writer.write_additions('directory', directories)
+        self.journal_writer.directory_add(directories)
 
         for directory in directories:
             try:
@@ -423,8 +403,7 @@
         missing = self.revision_missing([rev['id'] for rev in revisions])
         revisions = [rev for rev in revisions if rev['id'] in missing]
 
-        if self.journal_writer:
-            self.journal_writer.write_additions('revision', revisions)
+        self.journal_writer.revision_add(revisions)
 
         for revision in revisions:
             try:
@@ -521,8 +500,7 @@
         missing = self.release_missing([rel['id'] for rel in releases])
         releases = [rel for rel in releases if rel['id'] in missing]
 
-        if self.journal_writer:
-            self.journal_writer.write_additions('release', releases)
+        self.journal_writer.release_add(releases)
 
         for release in releases:
             try:
@@ -562,8 +540,7 @@
         snapshots = [snp for snp in snapshots if snp.id in missing]
 
         for snapshot in snapshots:
-            if self.journal_writer:
-                self.journal_writer.write_addition('snapshot', snapshot)
+            self.journal_writer.snapshot_add(snapshot)
 
             # Add branches
             for (branch_name, branch) in snapshot.branches.items():
@@ -814,8 +791,7 @@
         if known_origin:
             origin_url = known_origin['url']
         else:
-            if self.journal_writer:
-                self.journal_writer.write_addition('origin', origin)
+            self.journal_writer.origin_add_one(origin)
 
             self._cql_runner.origin_add_one(origin)
             origin_url = origin['url']
@@ -844,9 +820,7 @@
             'metadata': None,
             'visit': visit_id
         }
-
-        if self.journal_writer:
-            self.journal_writer.write_addition('origin_visit', visit)
+        self.journal_writer.origin_visit_add(visit, date, type)
 
         try:
             visit = OriginVisit.from_dict(visit)
@@ -886,8 +860,8 @@
         except (KeyError, TypeError, ValueError) as e:
             raise StorageArgumentException(*e.args)
 
-        if self.journal_writer:
-            self.journal_writer.write_update('origin_visit', visit)
+        self.journal_writer.origin_visit_update(
+            visit.to_dict(), visit_id, status, metadata, snapshot)
 
         self._cql_runner.origin_visit_update(origin_url, visit_id, updates)
 
@@ -897,9 +871,7 @@
             if isinstance(visit['date'], str):
                 visit['date'] = dateutil.parser.parse(visit['date'])
 
-        if self.journal_writer:
-            for visit in visits:
-                self.journal_writer.write_addition('origin_visit', visit)
+        self.journal_writer.origin_visit_upsert(visits)
 
         for visit in visits:
             visit = visit.copy()
diff --git a/swh/storage/in_memory.py b/swh/storage/in_memory.py
--- a/swh/storage/in_memory.py
+++ b/swh/storage/in_memory.py
@@ -27,9 +27,10 @@
 
 from . import HashCollision
 from .exc import StorageArgumentException
-from .storage import get_journal_writer
+
 from .converters import origin_url_to_sha1
 from .utils import get_partition_bounds_bytes
+from .writer import JournalWriter
 
 # Max block size of contents to return
 BULK_BLOCK_CONTENT_LEN_MAX = 10000
@@ -47,11 +48,7 @@
         self._skipped_content_indexes = defaultdict(lambda: defaultdict(set))
 
         self.reset()
-
-        if journal_writer:
-            self.journal_writer = get_journal_writer(**journal_writer)
-        else:
-            self.journal_writer = None
+        self.journal_writer = JournalWriter(journal_writer)
 
     def reset(self):
         self._directories = {}
@@ -84,14 +81,12 @@
                 raise StorageArgumentException('content with status=absent')
             if content.length is None:
                 raise StorageArgumentException('content with length=None')
+            try:
+                attr.evolve(content, data=None)
+            except (KeyError, TypeError, ValueError) as e:
+                raise StorageArgumentException(*e.args)
 
-        if self.journal_writer:
-            for content in contents:
-                try:
-                    content = attr.evolve(content, data=None)
-                except (KeyError, TypeError, ValueError) as e:
-                    raise StorageArgumentException(*e.args)
-                self.journal_writer.write_addition('content', content)
+        self.journal_writer.content_add(c.to_dict() for c in contents)
 
         summary = {
             'content:add': 0,
@@ -140,9 +135,7 @@
         return self._content_add(content, with_data=True)
 
     def content_update(self, content, keys=[]):
-        if self.journal_writer:
-            raise NotImplementedError(
-                'content_update is not yet supported with a journal_writer.')
+        self.journal_writer.content_update(content, keys=keys)
 
         for cont_update in content:
             cont_update = cont_update.copy()
@@ -295,9 +288,7 @@
                 raise StorageArgumentException(
                     f'Content with status={content.status}')
 
-        if self.journal_writer:
-            for content in contents:
-                self.journal_writer.write_addition('content', content)
+        self.journal_writer.skipped_content_add(contents)
 
         summary = {
             'skipped_content:add': 0
@@ -341,11 +332,10 @@
 
     def directory_add(self, directories):
         directories = list(directories)
-        if self.journal_writer:
-            self.journal_writer.write_additions(
-                'directory',
-                (dir_ for dir_ in directories
-                 if dir_['id'] not in self._directories))
+        self.journal_writer.directory_add(
+            dir_ for dir_ in directories
+            if dir_['id'] not in self._directories
+        )
 
         try:
             directories = [Directory.from_dict(d) for d in directories]
@@ -437,11 +427,10 @@
 
     def revision_add(self, revisions):
         revisions = list(revisions)
-        if self.journal_writer:
-            self.journal_writer.write_additions(
-                'revision',
-                (rev for rev in revisions
-                 if rev['id'] not in self._revisions))
+        self.journal_writer.revision_add(
+            rev for rev in revisions
+            if rev['id'] not in self._revisions
+        )
 
         try:
             revisions = [Revision.from_dict(rev) for rev in revisions]
@@ -498,11 +487,10 @@
 
     def release_add(self, releases):
         releases = list(releases)
-        if self.journal_writer:
-            self.journal_writer.write_additions(
-                'release',
-                (rel for rel in releases
-                 if rel['id'] not in self._releases))
+        self.journal_writer.release_add(
+            rel for rel in releases
+            if rel['id'] not in self._releases
+        )
 
         try:
             releases = [Release.from_dict(rel) for rel in releases]
@@ -543,9 +531,7 @@
         snapshots = (snap for snap in snapshots
                      if snap.id not in self._snapshots)
         for snapshot in snapshots:
-            if self.journal_writer:
-                self.journal_writer.write_addition('snapshot', snapshot)
-
+            self.journal_writer.snapshot_add(snapshot.to_dict())
             sorted_branch_names = sorted(snapshot.branches)
             self._snapshots[snapshot.id] = (snapshot, sorted_branch_names)
             self._objects[snapshot.id].append(('snapshot', snapshot.id))
@@ -761,9 +747,7 @@
         except (KeyError, TypeError, ValueError) as e:
             raise StorageArgumentException(*e.args)
         if origin.url not in self._origins:
-            if self.journal_writer:
-                self.journal_writer.write_addition('origin', origin)
-
+            self.journal_writer.origin_add_one(origin.to_dict())
             # generate an origin_id because it is needed by origin_get_range.
             # TODO: remove this when we remove origin_get_range
             origin_id = len(self._origins) + 1
@@ -813,8 +797,7 @@
             self._objects[(origin_url, visit_id)].append(
                 ('origin_visit', None))
 
-            if self.journal_writer:
-                self.journal_writer.write_addition('origin_visit', visit)
+            self.journal_writer.origin_visit_add(visit.to_dict(), date, type)
 
         return visit_ret
 
@@ -845,8 +828,8 @@
         except (KeyError, TypeError, ValueError) as e:
             raise StorageArgumentException(*e.args)
 
-        if self.journal_writer:
-            self.journal_writer.write_update('origin_visit', visit)
+        self.journal_writer.origin_visit_update(
+            visit.to_dict(), visit_id, status, metadata, snapshot)
 
         self._origin_visits[origin_url][visit_id-1] = visit
 
@@ -860,9 +843,7 @@
         except (KeyError, TypeError, ValueError) as e:
             raise StorageArgumentException(*e.args)
 
-        if self.journal_writer:
-            for visit in visits:
-                self.journal_writer.write_addition('origin_visit', visit)
+        self.journal_writer.origin_visit_upsert(v.to_dict() for v in visits)
 
         for visit in visits:
             visit_id = visit.visit
diff --git a/swh/storage/storage.py b/swh/storage/storage.py
--- a/swh/storage/storage.py
+++ b/swh/storage/storage.py
@@ -23,11 +23,6 @@
 from swh.model.hashutil import ALGORITHMS, hash_to_bytes, hash_to_hex
 from swh.objstorage import get_objstorage
 from swh.objstorage.exc import ObjNotFoundError
-try:
-    from swh.journal.writer import get_journal_writer
-except ImportError:
-    get_journal_writer = None  # type: ignore
-    # mypy limitation, see https://github.com/python/mypy/issues/1153
 
 from . import converters, HashCollision
 from .common import db_transaction_generator, db_transaction
@@ -36,6 +31,7 @@
 from .algos import diff
 from .metrics import timed, send_metric, process_metrics
 from .utils import get_partition_bounds_bytes
+from .writer import JournalWriter
 
 
 # Max block size of contents to return
@@ -93,14 +89,7 @@
             raise StorageDBError(e)
 
         self.objstorage = get_objstorage(**objstorage)
-        if journal_writer:
-            if get_journal_writer is None:
-                raise EnvironmentError(
-                    'You need the swh.journal package to use the '
-                    'journal_writer feature')
-            self.journal_writer = get_journal_writer(**journal_writer)
-        else:
-            self.journal_writer = None
+        self.journal_writer = JournalWriter(journal_writer)
 
     def get_db(self):
         if self._db:
@@ -218,12 +207,7 @@
         missing = list(self.content_missing(content, key_hash='sha1_git'))
         content = [c for c in content if c['sha1_git'] in missing]
 
-        if self.journal_writer:
-            for item in content:
-                if 'data' in item:
-                    item = item.copy()
-                    del item['data']
-                self.journal_writer.write_addition('content', item)
+        self.journal_writer.content_add(content)
 
         def add_to_objstorage():
             """Add to objstorage the new missing_content
@@ -265,10 +249,7 @@
     def content_update(self, content, keys=[], db=None, cur=None):
         # TODO: Add a check on input keys. How to properly implement
         # this? We don't know yet the new columns.
-
-        if self.journal_writer:
-            raise NotImplementedError(
-                'content_update is not yet supported with a journal_writer.')
+        self.journal_writer.content_update(content, keys=keys)
 
         db.mktemp('content', cur)
         select_keys = list(set(db.content_get_metadata_keys).union(set(keys)))
@@ -288,11 +269,7 @@
         missing = self.content_missing(content, key_hash='sha1_git')
         content = [c for c in content if c['sha1_git'] in missing]
 
-        if self.journal_writer:
-            for item in itertools.chain(content):
-                assert 'data' not in content
-                self.journal_writer.write_addition('content', item)
-
+        self.journal_writer.content_add_metadata(content)
         self._content_add_metadata(db, cur, content)
 
         return {
@@ -482,10 +459,7 @@
                               for algo in ALGORITHMS)
                           for missing_content in missing_contents)]
 
-        if self.journal_writer:
-            for item in content:
-                self.journal_writer.write_addition('content', item)
-
+        self.journal_writer.skipped_content_add(content)
         self._skipped_content_add_metadata(db, cur, content)
 
         return {
@@ -528,11 +502,10 @@
         if not dirs_missing:
             return summary
 
-        if self.journal_writer:
-            self.journal_writer.write_additions(
-                'directory',
-                (dir_ for dir_ in directories
-                 if dir_['id'] in dirs_missing))
+        self.journal_writer.directory_add(
+            dir_ for dir_ in directories
+            if dir_['id'] in dirs_missing
+        )
 
         # Copy directory ids
         dirs_missing_dict = ({'id': dir} for dir in dirs_missing)
@@ -612,8 +585,7 @@
             revision for revision in revisions
             if revision['id'] in revisions_missing]
 
-        if self.journal_writer:
-            self.journal_writer.write_additions('revision', revisions_filtered)
+        self.journal_writer.revision_add(revisions_filtered)
 
         revisions_filtered = map(converters.revision_to_db, revisions_filtered)
 
@@ -699,8 +671,7 @@
             if release['id'] in releases_missing
         ]
 
-        if self.journal_writer:
-            self.journal_writer.write_additions('release', releases_filtered)
+        self.journal_writer.release_add(releases_filtered)
 
         releases_filtered = map(converters.release_to_db, releases_filtered)
 
@@ -766,8 +737,7 @@
                 except VALIDATION_EXCEPTIONS + (KeyError,) as e:
                     raise StorageArgumentException(*e.args)
 
-                if self.journal_writer:
-                    self.journal_writer.write_addition('snapshot', snapshot)
+                self.journal_writer.snapshot_add(snapshot)
 
                 db.snapshot_add(snapshot['id'], cur)
                 count += 1
@@ -882,13 +852,18 @@
         with convert_validation_exceptions():
             visit_id = db.origin_visit_add(origin_url, date, type, cur)
 
-        if self.journal_writer:
-            # We can write to the journal only after inserting to the
-            # DB, because we want the id of the visit
-            self.journal_writer.write_addition('origin_visit', {
-                'origin': origin_url, 'date': date, 'type': type,
-                'visit': visit_id,
-                'status': 'ongoing', 'metadata': None, 'snapshot': None})
+        # We can write to the journal only after inserting to the
+        # DB, because we want the id of the visit
+        visit = {
+            'origin': origin_url,
+            'date': date,
+            'type': type,
+            'visit': visit_id,
+            'status': 'ongoing',
+            'metadata': None,
+            'snapshot': None
+        }
+        self.journal_writer.origin_visit_add(visit, date, type)
 
         send_metric('origin_visit:add', count=1, method_name='origin_visit')
         return {
@@ -921,9 +896,9 @@
             updates['snapshot'] = snapshot
 
         if updates:
-            if self.journal_writer:
-                self.journal_writer.write_update('origin_visit', {
-                    **visit, **updates})
+            updated_visit = {**visit, **updates}
+            self.journal_writer.origin_visit_update(
+                updated_visit, visit_id, status, metadata, snapshot)
 
             with convert_validation_exceptions():
                 db.origin_visit_update(origin_url, visit_id, updates, cur)
@@ -940,9 +915,7 @@
                     "visit['origin'] must be a string, not %r"
                     % (visit['origin'],))
 
-        if self.journal_writer:
-            for visit in visits:
-                self.journal_writer.write_addition('origin_visit', visit)
+        self.journal_writer.origin_visit_upsert(visits)
 
         for visit in visits:
             # TODO: upsert them all in a single query
@@ -1106,8 +1079,7 @@
         if origin_url:
             return origin_url
 
-        if self.journal_writer:
-            self.journal_writer.write_addition('origin', origin)
+        self.journal_writer.origin_add_one(origin)
 
         origins = db.origin_add(origin['url'], cur)
         send_metric('origin:add', count=len(origins), method_name='origin_add')
diff --git a/swh/storage/tests/test_api_client.py b/swh/storage/tests/test_api_client.py
--- a/swh/storage/tests/test_api_client.py
+++ b/swh/storage/tests/test_api_client.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2015-2018  The Software Heritage developers
+# Copyright (C) 2015-2020  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
@@ -60,6 +60,7 @@
 
 class TestStorage(_TestStorage):
     def test_content_update(self, swh_storage, app_server):
-        swh_storage.journal_writer = None  # TODO, journal_writer not supported
-        with patch.object(server.storage, 'journal_writer', None):
+        # TODO, journal_writer not supported
+        swh_storage.journal_writer.journal = None
+        with patch.object(server.storage.journal_writer, 'journal', None):
             super().test_content_update(swh_storage)
diff --git a/swh/storage/tests/test_storage.py b/swh/storage/tests/test_storage.py
--- a/swh/storage/tests/test_storage.py
+++ b/swh/storage/tests/test_storage.py
@@ -149,7 +149,7 @@
 
         expected_cont = data.cont
         del expected_cont['data']
-        journal_objects = list(swh_storage.journal_writer.objects)
+        journal_objects = list(swh_storage.journal_writer.journal.objects)
         for (obj_type, obj) in journal_objects:
             assert insertion_start_time <= obj['ctime']
             assert obj['ctime'] <= insertion_end_time
@@ -239,14 +239,14 @@
             'content:add': 1,
             'content:add:bytes': data.cont['length'],
             }
-        assert len(swh_storage.journal_writer.objects) == 1
+        assert len(swh_storage.journal_writer.journal.objects) == 1
 
         actual_result = swh_storage.content_add([data.cont, data.cont2])
         assert actual_result == {
             'content:add': 1,
             'content:add:bytes': data.cont2['length'],
             }
-        assert 2 <= len(swh_storage.journal_writer.objects) <= 3
+        assert 2 <= len(swh_storage.journal_writer.journal.objects) <= 3
 
         assert len(swh_storage.content_find(data.cont)) == 1
         assert len(swh_storage.content_find(data.cont2)) == 1
@@ -266,7 +266,7 @@
         assert cm.value.args[0] in ['sha1', 'sha1_git', 'blake2s256']
 
     def test_content_update(self, swh_storage):
-        swh_storage.journal_writer = None  # TODO, not supported
+        swh_storage.journal_writer.journal = None  # TODO, not supported
 
         cont = copy.deepcopy(data.cont)
 
@@ -297,7 +297,8 @@
             cont['sha1']: [expected_cont]
         }
 
-        assert list(swh_storage.journal_writer.objects) == [('content', cont)]
+        assert list(swh_storage.journal_writer.journal.objects) == [
+            ('content', cont)]
 
     def test_content_add_metadata_different_input(self, swh_storage):
         cont = data.cont
@@ -548,7 +549,7 @@
         actual_result = swh_storage.directory_add([data.dir])
         assert actual_result == {'directory:add': 1}
 
-        assert list(swh_storage.journal_writer.objects) == \
+        assert list(swh_storage.journal_writer.journal.objects) == \
             [('directory', data.dir)]
 
         actual_data = list(swh_storage.directory_ls(data.dir['id']))
@@ -570,7 +571,7 @@
         actual_result = swh_storage.directory_add(directories=_dir_gen())
         assert actual_result == {'directory:add': 1}
 
-        assert list(swh_storage.journal_writer.objects) == \
+        assert list(swh_storage.journal_writer.journal.objects) == \
             [('directory', data.dir)]
 
         swh_storage.refresh_stat_counters()
@@ -596,13 +597,13 @@
         actual_result = swh_storage.directory_add([data.dir])
         assert actual_result == {'directory:add': 1}
 
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('directory', data.dir)]
 
         actual_result = swh_storage.directory_add([data.dir])
         assert actual_result == {'directory:add': 0}
 
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('directory', data.dir)]
 
     def test_directory_get_recursive(self, swh_storage):
@@ -613,7 +614,7 @@
             [data.dir, data.dir2, data.dir3])
         assert actual_result == {'directory:add': 3}
 
-        assert list(swh_storage.journal_writer.objects) == [
+        assert list(swh_storage.journal_writer.journal.objects) == [
             ('directory', data.dir),
             ('directory', data.dir2),
             ('directory', data.dir3)]
@@ -650,7 +651,7 @@
             [data.dir, data.dir2, data.dir3])
         assert actual_result == {'directory:add': 3}
 
-        assert list(swh_storage.journal_writer.objects) == [
+        assert list(swh_storage.journal_writer.journal.objects) == [
             ('directory', data.dir),
             ('directory', data.dir2),
             ('directory', data.dir3)]
@@ -762,7 +763,7 @@
         end_missing = swh_storage.revision_missing([data.revision['id']])
         assert list(end_missing) == []
 
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('revision', data.revision)]
 
         # already there so nothing added
@@ -817,14 +818,14 @@
         actual_result = swh_storage.revision_add([data.revision])
         assert actual_result == {'revision:add': 1}
 
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('revision', data.revision)]
 
         actual_result = swh_storage.revision_add(
             [data.revision, data.revision2])
         assert actual_result == {'revision:add': 1}
 
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('revision', data.revision),
                 ('revision', data.revision2)]
 
@@ -866,7 +867,7 @@
         assert actual_results[0] == normalize_entity(data.revision4)
         assert actual_results[1] == normalize_entity(data.revision3)
 
-        assert list(swh_storage.journal_writer.objects) == [
+        assert list(swh_storage.journal_writer.journal.objects) == [
             ('revision', data.revision3),
             ('revision', data.revision4)]
 
@@ -960,7 +961,7 @@
                                                    data.release2['id']])
         assert list(end_missing) == []
 
-        assert list(swh_storage.journal_writer.objects) == [
+        assert list(swh_storage.journal_writer.journal.objects) == [
             ('release', data.release),
             ('release', data.release2)]
 
@@ -979,7 +980,7 @@
         actual_result = swh_storage.release_add(_rel_gen())
         assert actual_result == {'release:add': 2}
 
-        assert list(swh_storage.journal_writer.objects) == [
+        assert list(swh_storage.journal_writer.journal.objects) == [
             ('release', data.release),
             ('release', data.release2)]
 
@@ -998,7 +999,7 @@
         end_missing = swh_storage.release_missing([data.release['id']])
         assert list(end_missing) == []
 
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('release', release)]
 
     def test_release_add_validation(self, swh_storage):
@@ -1025,13 +1026,13 @@
         actual_result = swh_storage.release_add([data.release])
         assert actual_result == {'release:add': 1}
 
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('release', data.release)]
 
         actual_result = swh_storage.release_add([data.release, data.release2])
         assert actual_result == {'release:add': 1}
 
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('release', data.release),
                 ('release', data.release2)]
 
@@ -1113,7 +1114,7 @@
             del actual_origin['id']
             del actual_origin2['id']
 
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('origin', actual_origin),
                 ('origin', actual_origin2)]
 
@@ -1141,7 +1142,7 @@
             del actual_origin['id']
             del actual_origin2['id']
 
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('origin', actual_origin),
                 ('origin', actual_origin2)]
 
@@ -1150,12 +1151,12 @@
 
     def test_origin_add_twice(self, swh_storage):
         add1 = swh_storage.origin_add([data.origin, data.origin2])
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('origin', data.origin),
                 ('origin', data.origin2)]
 
         add2 = swh_storage.origin_add([data.origin, data.origin2])
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('origin', data.origin),
                 ('origin', data.origin2)]
 
@@ -1411,7 +1412,7 @@
             'metadata': None,
             'snapshot': None,
         }
-        objects = list(swh_storage.journal_writer.objects)
+        objects = list(swh_storage.journal_writer.journal.objects)
         assert ('origin', data.origin2) in objects
         assert ('origin_visit', origin_visit) in objects
 
@@ -1474,7 +1475,7 @@
         for visit in expected_visits:
             assert visit in actual_origin_visits
 
-        objects = list(swh_storage.journal_writer.objects)
+        objects = list(swh_storage.journal_writer.journal.objects)
         assert ('origin', data.origin2) in objects
 
         for visit in expected_visits:
@@ -1647,7 +1648,7 @@
             'metadata': None,
             'snapshot': None,
         }
-        objects = list(swh_storage.journal_writer.objects)
+        objects = list(swh_storage.journal_writer.journal.objects)
         assert ('origin', data.origin) in objects
         assert ('origin', data.origin2) in objects
         assert ('origin_visit', data1) in objects
@@ -1868,7 +1869,7 @@
             'metadata': None,
             'snapshot': None,
         }
-        assert list(swh_storage.journal_writer.objects) == [
+        assert list(swh_storage.journal_writer.journal.objects) == [
             ('origin', data.origin2),
             ('origin_visit', data1),
             ('origin_visit', data2)]
@@ -1929,7 +1930,7 @@
             'metadata': None,
             'snapshot': None,
         }
-        assert list(swh_storage.journal_writer.objects) == [
+        assert list(swh_storage.journal_writer.journal.objects) == [
             ('origin', data.origin2),
             ('origin_visit', data1),
             ('origin_visit', data2)]
@@ -2106,7 +2107,7 @@
             'metadata': None,
             'snapshot': data.empty_snapshot['id'],
         }
-        assert list(swh_storage.journal_writer.objects) == \
+        assert list(swh_storage.journal_writer.journal.objects) == \
             [('origin', data.origin),
              ('origin_visit', data1),
              ('snapshot', data.empty_snapshot),
@@ -2176,13 +2177,13 @@
         actual_result = swh_storage.snapshot_add([data.empty_snapshot])
         assert actual_result == {'snapshot:add': 1}
 
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('snapshot', data.empty_snapshot)]
 
         actual_result = swh_storage.snapshot_add([data.snapshot])
         assert actual_result == {'snapshot:add': 1}
 
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('snapshot', data.empty_snapshot),
                 ('snapshot', data.snapshot)]
 
@@ -2418,7 +2419,7 @@
         swh_storage.origin_add_one(data.origin)
         visit_id = 54164461156
 
-        swh_storage.journal_writer.objects[:] = []
+        swh_storage.journal_writer.journal.objects[:] = []
 
         swh_storage.snapshot_add([data.snapshot])
 
@@ -2426,7 +2427,7 @@
             swh_storage.origin_visit_update(
                 origin_url, visit_id, snapshot=data.snapshot['id'])
 
-        assert list(swh_storage.journal_writer.objects) == [
+        assert list(swh_storage.journal_writer.journal.objects) == [
             ('snapshot', data.snapshot)]
 
     def test_snapshot_add_twice__by_origin_visit(self, swh_storage):
@@ -2497,7 +2498,7 @@
             'metadata': None,
             'snapshot': data.snapshot['id'],
         }
-        assert list(swh_storage.journal_writer.objects) \
+        assert list(swh_storage.journal_writer.journal.objects) \
             == [('origin', data.origin),
                 ('origin_visit', data1),
                 ('snapshot', data.snapshot),
@@ -3684,7 +3685,7 @@
     """
 
     def test_content_update_with_new_cols(self, swh_storage):
-        swh_storage.journal_writer = None  # TODO, not supported
+        swh_storage.journal_writer.journal = None  # TODO, not supported
 
         with db_transaction(swh_storage) as (_, cur):
             cur.execute("""alter table content
@@ -3738,7 +3739,7 @@
 
         expected_cont = cont.copy()
         del expected_cont['data']
-        journal_objects = list(swh_storage.journal_writer.objects)
+        journal_objects = list(swh_storage.journal_writer.journal.objects)
         for (obj_type, obj) in journal_objects:
             del obj['ctime']
         assert journal_objects == [('content', expected_cont)]
@@ -3764,7 +3765,8 @@
         assert datum == (cont['sha1'], cont['sha1_git'], cont['sha256'],
                          cont['length'], 'visible')
 
-        assert list(swh_storage.journal_writer.objects) == [('content', cont)]
+        assert list(swh_storage.journal_writer.journal.objects) == [
+            ('content', cont)]
 
     def test_skipped_content_add_db(self, swh_storage):
         cont = data.skipped_cont
diff --git a/swh/storage/writer.py b/swh/storage/writer.py
new file mode 100644
--- /dev/null
+++ b/swh/storage/writer.py
@@ -0,0 +1,94 @@
+# Copyright (C) 2020 The Software Heritage developers
+# See the AUTHORS file at the top-level directory of this distribution
+# License: GNU General Public License version 3, or any later version
+# See top-level LICENSE file for more information
+
+try:
+    from swh.journal.writer import get_journal_writer
+except ImportError:
+    get_journal_writer = None  # type: ignore
+    # mypy limitation, see https://github.com/python/mypy/issues/1153
+
+
+class JournalWriter:
+    """Journal writer storage collaborator. It's in charge of adding objects to
+    the journal.
+
+    """
+    def __init__(self, journal_writer):
+        if journal_writer:
+            if get_journal_writer is None:
+                raise EnvironmentError(
+                    'You need the swh.journal package to use the '
+                    'journal_writer feature')
+            self.journal = get_journal_writer(**journal_writer)
+        else:
+            self.journal = None
+
+    def content_add(self, contents):
+        if not self.journal:
+            return
+        for item in contents:
+            if 'data' in item:
+                item = item.copy()
+                del item['data']
+            self.journal.write_addition('content', item)
+
+    def content_update(self, content, keys=[]):
+        if not self.journal:
+            return
+        raise NotImplementedError(
+            'content_update is not yet supported with a journal writer.')
+
+    def content_add_metadata(self, contents):
+        return self.content_add(contents)
+
+    def skipped_content_add(self, contents):
+        if not self.journal:
+            return
+        for item in contents:
+            self.journal.write_addition('content', item)
+
+    def directory_add(self, directories):
+        if not self.journal:
+            return
+        self.journal.write_additions('directory', directories)
+
+    def revision_add(self, revisions):
+        if not self.journal:
+            return
+        self.journal.write_additions('revision', revisions)
+
+    def release_add(self, releases):
+        if not self.journal:
+            return
+        self.journal.write_additions('release', releases)
+
+    def snapshot_add(self, snapshots):
+        if not self.journal:
+            return
+        snaps = snapshots if isinstance(snapshots, list) else [snapshots]
+        for snapshot in snaps:
+            self.journal.write_addition('snapshot', snapshot)
+
+    def origin_visit_add(self, origin, date, type):
+        if not self.journal:
+            return
+        self.journal.write_addition('origin_visit', origin)
+
+    def origin_visit_update(self, origin, visit_id, status=None,
+                            metadata=None, snapshot=None):
+        if not self.journal:
+            return
+        self.journal.write_update('origin_visit', origin)
+
+    def origin_visit_upsert(self, visits):
+        if not self.journal:
+            return
+        for visit in visits:
+            self.journal.write_addition('origin_visit', visit)
+
+    def origin_add_one(self, origin):
+        if not self.journal:
+            return
+        self.journal.write_addition('origin', origin)