diff --git a/swh/storage/api/client.py b/swh/storage/api/client.py
--- a/swh/storage/api/client.py
+++ b/swh/storage/api/client.py
@@ -34,6 +34,9 @@
     def content_missing_per_sha1(self, contents):
         return self.post('content/missing/sha1', {'contents': contents})
 
+    def skipped_content_missing(self, contents):
+        return self.post('content/skipped/missing', {'contents': contents})
+
     def content_get(self, content):
         return self.post('content/data', {'content': content})
 
diff --git a/swh/storage/api/server.py b/swh/storage/api/server.py
--- a/swh/storage/api/server.py
+++ b/swh/storage/api/server.py
@@ -149,6 +149,13 @@
         **decode_request(request)))
 
 
+@app.route('/content/skipped/missing', methods=['POST'])
+@timed
+def skipped_content_missing():
+    return encode_data(get_storage().skipped_content_missing(
+        **decode_request(request)))
+
+
 @app.route('/content/present', methods=['POST'])
 @timed
 def content_find():
diff --git a/swh/storage/storage.py b/swh/storage/storage.py
--- a/swh/storage/storage.py
+++ b/swh/storage/storage.py
@@ -476,7 +476,7 @@
             yield obj[0]
 
     @db_transaction_generator()
-    def skipped_content_missing(self, content, db=None, cur=None):
+    def skipped_content_missing(self, contents, db=None, cur=None):
         """List skipped_content missing from storage
 
         Args:
@@ -490,7 +490,7 @@
         keys = db.content_hash_keys
 
         db.mktemp('skipped_content', cur)
-        db.copy_to(content, 'tmp_skipped_content',
+        db.copy_to(contents, 'tmp_skipped_content',
                    keys + ['length', 'reason'], cur)
 
         yield from db.skipped_content_missing_from_temp(cur)
diff --git a/swh/storage/tests/test_in_memory.py b/swh/storage/tests/test_in_memory.py
--- a/swh/storage/tests/test_in_memory.py
+++ b/swh/storage/tests/test_in_memory.py
@@ -29,13 +29,18 @@
         pass
 
     @pytest.mark.skip('postgresql-specific test')
-    def test_skipped_content_add(self):
+    def test_skipped_content_add_db(self):
         pass
 
     @pytest.mark.skip('postgresql-specific test')
     def test_content_add_metadata_db(self):
         pass
 
+    @pytest.mark.skip(
+        'not implemented, see https://forge.softwareheritage.org/T1633')
+    def test_skipped_content_add(self):
+        pass
+
 
 @pytest.mark.db
 @pytest.mark.property_based
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
@@ -729,7 +729,7 @@
 
         self.assertIn(cm.exception.args[0], ['sha1', 'sha1_git', 'blake2s256'])
 
-    def test_skipped_content_add(self):
+    def test_skipped_content_add_db(self):
         cont = self.skipped_cont.copy()
         cont2 = self.skipped_cont2.copy()
         cont2['blake2s256'] = None
@@ -767,6 +767,27 @@
              'Content too long')
         )
 
+    def test_skipped_content_add(self):
+        cont = self.skipped_cont.copy()
+        cont2 = self.skipped_cont2.copy()
+        cont2['blake2s256'] = None
+
+        missing = list(self.storage.skipped_content_missing([cont, cont2]))
+
+        self.assertEqual(len(missing), 2, missing)
+
+        actual_result = self.storage.content_add([cont, cont, cont2])
+
+        self.assertEqual(actual_result, {
+            'content:add': 0,
+            'content:bytes:add': 0,
+            'skipped_content:add': 2,
+        })
+
+        missing = list(self.storage.skipped_content_missing([cont, cont2]))
+
+        self.assertEqual(missing, [])
+
     @pytest.mark.property_based
     @given(strategies.sets(
         elements=strategies.sampled_from(