diff --git a/hyperforge/src/hyperforge/api/v1/mcp_interaction.py b/hyperforge/src/hyperforge/api/v1/mcp_interaction.py
index 046937c..ccd7e50 100644
--- a/hyperforge/src/hyperforge/api/v1/mcp_interaction.py
+++ b/hyperforge/src/hyperforge/api/v1/mcp_interaction.py
@@ -188,9 +188,7 @@ def _default_oauth_metadata(app: "HTTPApplication") -> tuple[list[str], list[str
     return [], []
 
 
-def _get_mcp_auth_config(
-    app: "HTTPApplication", agent_id: str
-):
+def _get_mcp_auth_config(app: "HTTPApplication", agent_id: str):
     return get_enabled_mcp_auth(app._agents_cfg, agent_id)
 
 
diff --git a/hyperforge/src/hyperforge/standalone/oauth.py b/hyperforge/src/hyperforge/standalone/oauth.py
index 2ce02ec..1e39338 100644
--- a/hyperforge/src/hyperforge/standalone/oauth.py
+++ b/hyperforge/src/hyperforge/standalone/oauth.py
@@ -12,9 +12,9 @@
 from hyperforge.standalone.config import StandAloneAgentConfig, StandaloneMCPAuthConfig
 
 _HASHES = {
-    "RS256": SHA256,
-    "RS384": SHA384,
-    "RS512": SHA512,
+    "RS256": SHA256(),
+    "RS384": SHA384(),
+    "RS512": SHA512(),
 }
 
 
@@ -110,7 +110,7 @@ async def _validate_jwt(
             signature,
             signed_payload,
             padding.PKCS1v15(),
-            _HASHES[alg](),
+            _HASHES[alg],
         )
     except Exception as exc:
         raise AuthenticationError("Invalid bearer token signature") from exc
diff --git a/hyperforge/tests/standalone/test_mcp_auth.py b/hyperforge/tests/standalone/test_mcp_auth.py
index 307db73..2d733f2 100644
--- a/hyperforge/tests/standalone/test_mcp_auth.py
+++ b/hyperforge/tests/standalone/test_mcp_auth.py
@@ -8,12 +8,13 @@
 from cryptography.hazmat.primitives.asymmetric import padding, rsa
 from cryptography.hazmat.primitives.hashes import SHA256
 from httpx import ASGITransport, AsyncClient
+from starlette.datastructures import Headers
+
 from hyperforge.api.v1.mcp_interaction import _prepare_interaction_headers
 from hyperforge.standalone import oauth as standalone_oauth
 from hyperforge.standalone.app import StandaloneApplication
 from hyperforge.standalone.config import StandaloneConfig
 from hyperforge.standalone.settings import StandaloneSettings
-from starlette.datastructures import Headers
 
 pytestmark = pytest.mark.asyncio
 
@@ -103,6 +104,7 @@ async def client(agents_config, standalone_settings):
 def signing_key():
     return rsa.generate_private_key(public_exponent=65537, key_size=2048)
 
+
 @pytest.fixture
 def jwks(signing_key):
     public_numbers = signing_key.public_key().public_numbers()
@@ -231,9 +233,7 @@ async def test_protected_mcp_default_metadata_url_uses_https(client: AsyncClient
     )
 
 
-async def test_protected_mcp_accepts_signed_bearer(
-    client: AsyncClient, signing_key
-):
+async def test_protected_mcp_accepts_signed_bearer(client: AsyncClient, signing_key):
     response = await client.delete(
         f"/api/v1/agent/{AGENT_ID}/session/s1/mcp",
         headers={"Authorization": f"Bearer {make_token(signing_key)}"},
@@ -247,7 +247,9 @@ async def test_protected_mcp_rejects_token_with_wrong_audience(
 ):
     response = await client.delete(
         f"/api/v1/agent/{AGENT_ID}/session/s1/mcp",
-        headers={"Authorization": f"Bearer {make_token(signing_key, aud='api://other')}"},
+        headers={
+            "Authorization": f"Bearer {make_token(signing_key, aud='api://other')}"
+        },
     )
 
     assert response.status_code == 401
@@ -264,9 +266,7 @@ async def test_protected_mcp_rejects_tampered_token(client: AsyncClient, signing
         "scp": REQUIRED_SCOPE,
         "sub": "tampered",
     }
-    tampered_token = (
-        f"{header_raw}.{_b64encode_json(tampered_claims)}.{signature_raw}"
-    )
+    tampered_token = f"{header_raw}.{_b64encode_json(tampered_claims)}.{signature_raw}"
 
     response = await client.delete(
         f"/api/v1/agent/{AGENT_ID}/session/s1/mcp",
@@ -285,7 +285,9 @@ async def test_protected_mcp_rejects_token_without_required_scope(
 ):
     response = await client.delete(
         f"/api/v1/agent/{AGENT_ID}/session/s1/mcp",
-        headers={"Authorization": f"Bearer {make_token(signing_key, scp='other:read')}"},
+        headers={
+            "Authorization": f"Bearer {make_token(signing_key, scp='other:read')}"
+        },
     )
 
     assert response.status_code == 401