diff --git a/mypy.ini b/mypy.ini
--- a/mypy.ini
+++ b/mypy.ini
@@ -17,6 +17,9 @@
 [mypy-confluent_kafka.*]
 ignore_missing_imports = True
 
+[mypy-deprecated.*]
+ignore_missing_imports = True
+
 # only shipped indirectly via hypothesis
 [mypy-django.*]
 ignore_missing_imports = True
diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,3 +5,4 @@
 aiohttp
 tenacity
 cassandra-driver >= 3.19.0, != 3.21.0
+deprecated
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
@@ -11,6 +11,7 @@
 from typing import Any, Dict, List, Iterable, Optional
 
 import attr
+from deprecated import deprecated
 
 from swh.core.api.serializers import msgpack_loads, msgpack_dumps
 from swh.model.model import (
@@ -775,6 +776,7 @@
             self._cql_runner.origin_add_one(origin)
         return {"origin:add": len(to_add)}
 
+    @deprecated("Use origin_add([origin]) instead")
     def origin_add_one(self, origin: Origin) -> str:
         known_origin = self.origin_get_one(origin.to_dict())
 
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
@@ -29,6 +29,8 @@
 
 import attr
 
+from deprecated import deprecated
+
 from swh.core.api.serializers import msgpack_loads, msgpack_dumps
 from swh.model.model import (
     BaseContent,
@@ -763,6 +765,7 @@
 
         return {"origin:add": added}
 
+    @deprecated("Use origin_add([origin]) instead")
     def origin_add_one(self, origin: Origin) -> str:
         if origin.url not in self._origins:
             self.journal_writer.origin_add([origin])
diff --git a/swh/storage/interface.py b/swh/storage/interface.py
--- a/swh/storage/interface.py
+++ b/swh/storage/interface.py
@@ -1065,6 +1065,7 @@
         """
         ...
 
+    @deprecated
     @remote_api_endpoint("origin/add")
     def origin_add_one(self, origin: Origin) -> str:
         """Add origin to the storage
diff --git a/swh/storage/storage.py b/swh/storage/storage.py
--- a/swh/storage/storage.py
+++ b/swh/storage/storage.py
@@ -9,6 +9,7 @@
 
 from collections import defaultdict
 from contextlib import contextmanager
+from deprecated import deprecated
 from typing import Any, Dict, Iterable, List, Optional
 
 import attr
@@ -1108,6 +1109,7 @@
                 added += 1
         return {"origin:add": added}
 
+    @deprecated("Use origin_add([origin]) instead")
     @timed
     @db_transaction()
     def origin_add_one(self, origin: Origin, db=None, cur=None) -> str:
diff --git a/swh/storage/validate.py b/swh/storage/validate.py
--- a/swh/storage/validate.py
+++ b/swh/storage/validate.py
@@ -6,6 +6,8 @@
 import contextlib
 from typing import Dict, Iterable, Iterator, Optional, Tuple, Type, TypeVar, Union
 
+from deprecated import deprecated
+
 from swh.model.model import (
     SkippedContent,
     Content,
@@ -141,6 +143,7 @@
     def origin_add(self, origins: Iterable[Union[Dict, Origin]]) -> Dict[str, int]:
         return self.storage.origin_add([dict_converter(Origin, o) for o in origins])
 
+    @deprecated("Use origin_add([origin]) instead")
     def origin_add_one(self, origin: Union[Dict, Origin]) -> int:
         return self.storage.origin_add_one(dict_converter(Origin, origin))