fix(mcp): retain profile secret scope during discovery

(cherry picked from commit f344095fcf16c5d154ef2d207cce9b13339bf2e4)

hermes_cli/mcp_startup.py

@@ -4,10 +4,9 @@ from __future__ import annotations
 
 import threading
 from contextlib import nullcontext
+from contextvars import copy_context
 from typing import Optional
 
-from hermes_constants import get_hermes_home_override, reset_hermes_home_override, set_hermes_home_override
-
 _mcp_discovery_lock = threading.Lock()
 _mcp_discovery_started = False
 _mcp_discovery_thread: Optional[threading.Thread] = None
@@ -95,15 +94,13 @@ def start_background_mcp_discovery(*, logger, thread_name: str) -> None:
         if not _has_configured_mcp_servers():
             return
 
-        # Re-install the caller's context-local HERMES_HOME override (multi-profile dashboard/desktop
-        # backends) inside the thread: ContextVars don't propagate into bare threads, so a session
-        # switched to profile X would otherwise discover the LAUNCH profile's mcp_servers.
-        # The config gate above already runs on the caller's thread, so it sees the same override. See
-        # #67605.
-        home_override = get_hermes_home_override()
-
+        # Bare threads start from an empty context: run discovery under a copy of the caller's, so
+        # the context-local HERMES_HOME override (multi-profile dashboard/desktop backends, #67605)
+        # AND the profile's secret scope reach it. Without the scope a session switched to profile
+        # X would discover the LAUNCH profile's mcp_servers, and ``${TOKEN}`` interpolation / the
+        # stdio child env would fail closed (multiplex) or resolve the launch profile's value.
+        # The config gate above already runs on the caller's thread, so it sees the same context.
         def _discover() -> None:
-            token = set_hermes_home_override(home_override)
             try:
                 _discover_mcp_tools_without_interactive_oauth()
                 try:
@@ -114,12 +111,11 @@ def start_background_mcp_discovery(*, logger, thread_name: str) -> None:
             except Exception:
                 logger.debug("Background MCP tool discovery failed", exc_info=True)
             finally:
-                reset_hermes_home_override(token)
                 with _mcp_discovery_lock:
                     global _mcp_discovery_thread
                     _mcp_discovery_thread = None
 
-        thread = threading.Thread(target=_discover, name=thread_name, daemon=True)
+        thread = threading.Thread(target=copy_context().run, args=(_discover,), name=thread_name, daemon=True)
         _mcp_discovery_thread = thread
         thread.start()
 

tests/hermes_cli/test_mcp_startup.py

@@ -236,6 +236,46 @@ def test_background_mcp_discovery_suppresses_interactive_oauth(monkeypatch):
     assert state["active"] is False
 
 
+def test_background_mcp_discovery_propagates_profile_secret_scope(monkeypatch):
+    """A dashboard-profile discovery thread must retain that profile's secrets."""
+    from agent.secret_scope import current_secret_scope, reset_secret_scope, set_secret_scope
+
+    seen = []
+    monkeypatch.setitem(
+        sys.modules,
+        "hermes_cli.config",
+        types.SimpleNamespace(
+            read_raw_config=lambda: {"mcp_servers": {"demo": {"url": "https://mcp.example.test/mcp"}}},
+        ),
+    )
+    monkeypatch.setitem(
+        sys.modules,
+        "tools.mcp_oauth",
+        types.SimpleNamespace(suppress_interactive_oauth=lambda: nullcontext()),
+    )
+    monkeypatch.setitem(
+        sys.modules,
+        "tools.mcp_tool_discovery",
+        types.SimpleNamespace(
+            discover_mcp_tools=lambda: seen.append(dict(current_secret_scope() or {})),
+        ),
+    )
+
+    expected_scope = {"MCP_DEMO_TOKEN": "profile-only-secret"}
+    token = set_secret_scope(expected_scope)
+    try:
+        mcp_startup.start_background_mcp_discovery(
+            logger=types.SimpleNamespace(debug=lambda *_a, **_k: None),
+            thread_name="test-mcp-discovery",
+        )
+        assert mcp_startup._mcp_discovery_thread is not None
+        mcp_startup._mcp_discovery_thread.join(timeout=1.0)
+    finally:
+        reset_secret_scope(token)
+
+    assert seen == [expected_scope]
+
+
 def test_portable_only_mcp_configuration_opens_startup_gate(monkeypatch):
     monkeypatch.setitem(
         sys.modules,