diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,3 +3,4 @@
 python-magic >= 0.4.13
 pyld
 xmltodict
+typing-extensions
diff --git a/swh/indexer/storage/__init__.py b/swh/indexer/storage/__init__.py
--- a/swh/indexer/storage/__init__.py
+++ b/swh/indexer/storage/__init__.py
@@ -3,10 +3,13 @@
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
+from __future__ import annotations
 
 from collections import Counter
+from importlib import import_module
 import json
-from typing import Dict, Iterable, List, Optional, Tuple, Union
+from typing import TYPE_CHECKING, Dict, Iterable, List, Optional, Tuple, Union
+import warnings
 
 import psycopg2
 import psycopg2.pool
@@ -32,38 +35,61 @@
     RevisionIntrinsicMetadataRow,
 )
 
+if TYPE_CHECKING:
+    from swh.indexer.storage.interface import IndexerStorageInterface
+
 INDEXER_CFG_KEY = "indexer_storage"
 
 
 MAPPING_NAMES = ["codemeta", "gemspec", "maven", "npm", "pkg-info"]
 
 
-def get_indexer_storage(cls, args):
-    """Get an indexer storage object of class `storage_class` with
+SERVER_IMPLEMENTATIONS: Dict[str, str] = {
+    "local": ".IndexerStorage",
+    "remote": ".api.client.RemoteStorage",
+    "memory": ".in_memory.IndexerStorage",
+}
+
+
+def get_indexer_storage(cls: str, **kwargs) -> IndexerStorageInterface:
+    """Get an indexer storage object of class `cls` with
     arguments `storage_args`.
 
     Args:
-        cls (str): storage's class, either 'local' or 'remote'
-        args (dict): dictionary of arguments passed to the
-            storage class constructor
+        cls: storage's class, either 'local' or 'remote'
+        kwargs: dictionary of arguments passed to the
+            indexer storage class constructor
 
     Returns:
-        an instance of swh.indexer's storage (either local or remote)
+        an instance of swh.indexer.storage (either local, remote, memory)
 
     Raises:
         ValueError if passed an unknown storage class.
 
     """
-    if cls == "remote":
-        from .api.client import RemoteStorage as IndexerStorage
-    elif cls == "local":
-        from . import IndexerStorage
-    elif cls == "memory":
-        from .in_memory import IndexerStorage
-    else:
-        raise ValueError("Unknown indexer storage class `%s`" % cls)
-
-    return IndexerStorage(**args)
+    if "args" in kwargs:
+        warnings.warn(
+            'Explicit "args" key is deprecated, use keys directly instead.',
+            DeprecationWarning,
+        )
+        kwargs = kwargs["args"]
+
+    class_path = SERVER_IMPLEMENTATIONS.get(cls)
+    if class_path is None:
+        raise ValueError(
+            f"Unknown indexer storage class `{cls}`. "
+            f"Supported: {', '.join(SERVER_IMPLEMENTATIONS)}"
+        )
+
+    (module_path, class_name) = class_path.rsplit(".", 1)
+    module = import_module(module_path if module_path else ".", package=__package__)
+    IndexerStorage = getattr(module, class_name)
+    check_config = kwargs.pop("check_config", {})
+    idx_storage = IndexerStorage(**kwargs)
+    if check_config:
+        if not idx_storage.check_config(**check_config):
+            raise EnvironmentError("Indexer storage check config failed")
+    return idx_storage
 
 
 def check_id_duplicates(data):
diff --git a/swh/indexer/storage/interface.py b/swh/indexer/storage/interface.py
--- a/swh/indexer/storage/interface.py
+++ b/swh/indexer/storage/interface.py
@@ -5,6 +5,8 @@
 
 from typing import Dict, Iterable, List, Optional, Tuple, TypeVar, Union
 
+from typing_extensions import Protocol, runtime_checkable
+
 from swh.core.api import remote_api_endpoint
 from swh.core.api.classes import PagedResult as CorePagedResult
 from swh.indexer.storage.model import (
@@ -24,7 +26,8 @@
 Sha1 = bytes
 
 
-class IndexerStorageInterface:
+@runtime_checkable
+class IndexerStorageInterface(Protocol):
     @remote_api_endpoint("check_config")
     def check_config(self, *, check_write):
         """Check that the storage is configured and ready to go."""
diff --git a/swh/indexer/tests/storage/test_init.py b/swh/indexer/tests/storage/test_init.py
new file mode 100644
--- /dev/null
+++ b/swh/indexer/tests/storage/test_init.py
@@ -0,0 +1,52 @@
+# 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
+
+import pytest
+
+from swh.indexer.storage import IndexerStorage, get_indexer_storage
+from swh.indexer.storage.api.client import RemoteStorage
+from swh.indexer.storage.in_memory import IndexerStorage as MemoryIndexerStorage
+from swh.indexer.storage.interface import IndexerStorageInterface
+
+SERVER_IMPLEMENTATIONS_KWARGS = [
+    ("remote", RemoteStorage, {"url": "localhost"}),
+    ("local", IndexerStorage, {"db": "something"}),
+]
+
+SERVER_IMPLEMENTATIONS = SERVER_IMPLEMENTATIONS_KWARGS + [
+    ("memory", MemoryIndexerStorage, {}),
+]
+
+
+@pytest.fixture
+def mock_psycopg2(mocker):
+    mocker.patch("swh.indexer.storage.psycopg2.pool")
+    return mocker
+
+
+def test_init_get_indexer_storage_failure():
+    with pytest.raises(ValueError, match="Unknown indexer storage class"):
+        get_indexer_storage("unknown-idx-storage")
+
+
+@pytest.mark.parametrize("class_name,expected_class,kwargs", SERVER_IMPLEMENTATIONS)
+def test_init_get_indexer_storage(class_name, expected_class, kwargs, mock_psycopg2):
+    if kwargs:
+        concrete_idx_storage = get_indexer_storage(class_name, **kwargs)
+    else:
+        concrete_idx_storage = get_indexer_storage(class_name)
+    assert isinstance(concrete_idx_storage, expected_class)
+    assert isinstance(concrete_idx_storage, IndexerStorageInterface)
+
+
+@pytest.mark.parametrize(
+    "class_name,expected_class,kwargs", SERVER_IMPLEMENTATIONS_KWARGS
+)
+def test_init_get_indexer_storage_deprecation_warning(
+    class_name, expected_class, kwargs, mock_psycopg2
+):
+    with pytest.warns(DeprecationWarning):
+        concrete_idx_storage = get_indexer_storage(class_name, args=kwargs)
+    assert isinstance(concrete_idx_storage, expected_class)