diff --git a/src/oidcop/session/grant.py b/src/oidcop/session/grant.py
index 86c7915b..74f9be93 100644
--- a/src/oidcop/session/grant.py
+++ b/src/oidcop/session/grant.py
@@ -186,11 +186,23 @@ def payload_arguments(
         if not scope:
             scope = self.scope
 
-        payload = {"scope": scope, "aud": self.resources}
+        payload = {
+            "scope": scope,
+            "aud": self.resources,
+            "jti" : uuid1().hex
+        }
 
         if extra_payload:
             payload.update(extra_payload)
 
+        if self.authorization_request:
+            client_id = self.authorization_request.get('client_id')
+            if client_id:
+                payload.update({
+                    "client_id": client_id,
+                    'sub': client_id
+                })
+
         _claims_restriction = endpoint_context.claims_interface.get_claims(
             session_id, scopes=scope, usage=token_type
         )
@@ -262,19 +274,16 @@ def mint_token(
             )
             if token_handler is None:
                 token_handler = endpoint_context.session_manager.token_handler.handler[
-                    GRANT_TYPE_MAP[token_type]
-                ]
-
-            item.value = token_handler(
-                session_id=session_id,
-                **self.payload_arguments(
-                    session_id,
-                    endpoint_context,
-                    token_type=token_type,
-                    scope=scope,
-                    extra_payload=handler_args,
-                ),
-            )
+                    GRANT_TYPE_MAP[token_type]]
+
+            token_payload = self.payload_arguments(session_id,
+                                                   endpoint_context,
+                                                   token_type=token_type,
+                                                   scope=scope,
+                                                   extra_payload=handler_args)
+            item.value = token_handler(session_id=session_id,
+                                       **token_payload)
+
         else:
             raise ValueError("Can not mint that kind of token")
 
diff --git a/src/oidcop/token/jwt_token.py b/src/oidcop/token/jwt_token.py
index b64a7fdc..049e3f1e 100644
--- a/src/oidcop/token/jwt_token.py
+++ b/src/oidcop/token/jwt_token.py
@@ -44,9 +44,15 @@ def __init__(
         self.def_aud = aud or []
         self.alg = alg
 
-    def __call__(
-        self, session_id: Optional[str] = "", ttype: Optional[str] = "", **payload
-    ) -> str:
+    def load_custom_claims(self, payload:dict={}):
+        # inherit me and do your things here
+        return payload
+
+    def __call__(self,
+                 session_id: Optional[str] = '',
+                 ttype: Optional[str] = '',
+                 **payload) -> str:
+
         """
         Return a token.
 
@@ -61,7 +67,12 @@ def __call__(
         else:
             ttype = "A"
 
-        payload.update({"sid": session_id, "ttype": ttype})
+        payload.update(
+            {"sid": session_id,
+             "ttype": ttype
+            }
+        )
+        payload = self.load_custom_claims(payload)
 
         # payload.update(kwargs)
         _context = self.server_get("endpoint_context")