diff --git a/duniterpy/api/ws2p/network.py b/duniterpy/api/ws2p/network.py
index b7fa58aff2f4d19730b8527633f9d21e1b61d494..ec9b3a149309083f077926aca1cb5cf79982103a 100644
--- a/duniterpy/api/ws2p/network.py
+++ b/duniterpy/api/ws2p/network.py
@@ -54,4 +54,12 @@ WS2P_HEADS_SCHEMA = {
     "required": ["heads"]
 }
 
-# todo: support ws2p v1 api
+
+def heads(client: Client):
+    """
+    GET Certification data over a member
+
+    :param client: Client to connect to the api
+    :rtype: dict
+    """
+    return client.get(MODULE + '/ws2p/heads', schema=WS2P_HEADS_SCHEMA)
diff --git a/duniterpy/documents/ws2p/heads.py b/duniterpy/documents/ws2p/heads.py
index 1f63d90b0e408c71cbb39606d16b3deb064a670d..7d020e825d93a6a14fbec73e0152f9dbbb8eb847 100644
--- a/duniterpy/documents/ws2p/heads.py
+++ b/duniterpy/documents/ws2p/heads.py
@@ -22,8 +22,8 @@ class API:
         data = API.re_inline.match(inline)
         if data is None:
             raise MalformedDocumentError("WS2P API Document")
-        private = data.group(1)
-        public = data.group(2)
+        private = "" if data.group(1) is None else data.group(1)
+        public = "" if data.group(2) is None else data.group(2)
         return cls(private, public)
 
     def __str__(self) -> str:
diff --git a/duniterpy/key/verifying_key.py b/duniterpy/key/verifying_key.py
index ba4652a65f001b70a7d2086e807134238f3e8441..aa419abeefad79507bd9c18c3032c5a1e1f617a4 100644
--- a/duniterpy/key/verifying_key.py
+++ b/duniterpy/key/verifying_key.py
@@ -5,11 +5,12 @@ duniter public and private keys
 """
 
 import base64
+from typing import Any
+
 import libnacl.sign
 import libnacl.encode
 
 from duniterpy.documents import Document
-from duniterpy.documents.ws2p.heads import HeadV2
 from .base58 import Base58Encoder
 
 
@@ -41,10 +42,10 @@ class VerifyingKey(libnacl.sign.Verifier):
         except ValueError:
             return False
 
-    def verify_ws2p_head(self, head: HeadV2) -> bool:
+    def verify_ws2p_head(self, head: Any) -> bool:
         """
         Check specified document
-        :param HeadV2 head:
+        :param Any head:
         :return:
         """
         signature = base64.b64decode(head.signature)