fix(mcp): preserve config overrides for profile reads (#5619)

api/config.py

@@ -703,6 +703,13 @@ def get_config_for_profile_home(profile_home: "Path | str | None") -> dict:
         target = Path(profile_home).expanduser()
     except Exception:
         return get_config()
+    try:
+        from api.profiles import get_active_hermes_home
+
+        if Path(get_active_hermes_home()).expanduser() == target:
+            return get_config()
+    except Exception:
+        pass
     # If the ambient resolver already points at this profile home, defer to
     # get_config() so in-memory overrides (monkeypatched cfg) are honored. This
     # MUST run before the nonexistent-home guard below: a matching ambient home

tests/test_issue3294_profile_toolset_scoping.py

@@ -108,6 +108,31 @@ def test_matching_home_defers_to_get_config(_two_profiles):
     ]
 
 
+def test_active_home_with_external_config_override_defers_to_get_config(_two_profiles, monkeypatch, tmp_path):
+    """The active home still honors HERMES_CONFIG_PATH when the override lives
+    outside that home."""
+    cfg, default_home, profile_b_home = _two_profiles
+    from api import profiles
+
+    active_home = tmp_path / "active-home"
+    override_path = tmp_path / "override-dir" / "config.yaml"
+    active_home.mkdir()
+    _write_cfg(active_home, ["wrong-active-home-file"])
+    override_path.parent.mkdir()
+    import yaml
+
+    override_path.write_text(
+        yaml.safe_dump({"platform_toolsets": {"cli": ["override-config"]}}, sort_keys=False),
+        encoding="utf-8",
+    )
+    monkeypatch.setenv("HERMES_CONFIG_PATH", str(override_path))
+    monkeypatch.setattr(profiles, "get_active_hermes_home", lambda: active_home)
+    cfg.reload_config()
+
+    same = cfg.get_config_for_profile_home(active_home)
+    assert same.get("platform_toolsets", {}).get("cli") == ["override-config"]
+
+
 def test_matching_ambient_home_that_does_not_exist_still_defers_to_get_config(_two_profiles, monkeypatch, tmp_path):
     """Regression (#4516 gate): the nonexistent-home guard must run AFTER the
     ambient-resolver short-circuit. A home that matches the ambient config path

tests/test_issue538_mcp_management.py

@@ -1,6 +1,7 @@
 """Tests for issue #538 — MCP server management API."""
 import json, pytest
 from unittest.mock import patch, MagicMock, call
+import yaml
 from api.routes import (
     _handle_mcp_servers_list,
     _handle_mcp_server_update,
@@ -141,6 +142,41 @@ class TestMcpList:
         """YAML numeric false-y values should not show a disabled server as enabled."""
         assert _parse_mcp_enabled(0) is False
 
+    def test_active_home_list_reads_external_config_override_used_by_writes(self, monkeypatch, tmp_path):
+        """HERMES_CONFIG_PATH outside the active home remains the read/write authority."""
+        from api import config, profiles, routes
+
+        active_home = tmp_path / 'active-home'
+        override_path = tmp_path / 'override-dir' / 'config.yaml'
+        active_home.mkdir()
+        override_path.parent.mkdir()
+        active_home.joinpath('config.yaml').write_text(
+            yaml.safe_dump({'mcp_servers': {'wrong-home': {'command': 'wrong'}}}, sort_keys=False),
+            encoding='utf-8',
+        )
+        override_path.write_text(
+            yaml.safe_dump({'mcp_servers': {'override-srv': {'command': 'override'}}}, sort_keys=False),
+            encoding='utf-8',
+        )
+        monkeypatch.setenv('HERMES_CONFIG_PATH', str(override_path))
+        monkeypatch.setattr(profiles, 'get_active_hermes_home', lambda: active_home)
+        monkeypatch.setattr(routes, 'get_active_hermes_home', lambda: active_home)
+        monkeypatch.setattr(routes, '_mcp_runtime_status_by_name', lambda: {})
+        config.reload_config()
+
+        h = _make_handler()
+        _handle_mcp_servers_list(h)
+        payload = _json_payload(h)
+        assert [srv['name'] for srv in payload['servers']] == ['override-srv']
+
+        h = _make_handler()
+        h.command = 'PUT'
+        _handle_mcp_server_update(h, 'new-srv', {'command': 'new-command'})
+        saved = yaml.safe_load(override_path.read_text(encoding='utf-8'))
+        active_home_saved = yaml.safe_load(active_home.joinpath('config.yaml').read_text(encoding='utf-8'))
+        assert 'new-srv' in saved['mcp_servers']
+        assert 'new-srv' not in active_home_saved['mcp_servers']
+
 
 class TestMcpSave:
     """PUT /api/mcp/servers/<name> — add or update."""