oauth2.1 truly works

core/context.py

@@ -7,6 +7,11 @@ _injected_oauth_credentials = contextvars.ContextVar(
     "injected_oauth_credentials", default=None
 )
 
+# Context variable to hold FastMCP session ID for the life of a single request.
+_fastmcp_session_id = contextvars.ContextVar(
+    "fastmcp_session_id", default=None
+)
+
 def get_injected_oauth_credentials():
     """
     Retrieve injected OAuth credentials for the current request context.
@@ -19,4 +24,18 @@ def set_injected_oauth_credentials(credentials: Optional[dict]):
     Set or clear the injected OAuth credentials for the current request context.
     This is called by the service decorator.
     """
-    _injected_oauth_credentials.set(credentials)
+    _injected_oauth_credentials.set(credentials)
+
+def get_fastmcp_session_id() -> Optional[str]:
+    """
+    Retrieve the FastMCP session ID for the current request context.
+    This is called by authentication layer to get the current session.
+    """
+    return _fastmcp_session_id.get()
+
+def set_fastmcp_session_id(session_id: Optional[str]):
+    """
+    Set or clear the FastMCP session ID for the current request context.
+    This is called when a FastMCP request starts.
+    """
+    _fastmcp_session_id.set(session_id)