fix(agent): preserve active-profile SOUL identity for delegated children

tests/tools/test_delegate.py

@@ -11,6 +11,7 @@
 
 import json
 import os
+from pathlib import Path
 import threading
 import time
 import types
@@ -147,6 +148,112 @@ def test_goal_only(self):
         self.assertIn("YOUR TASK", prompt)
         self.assertNotIn("CONTEXT", prompt)
 
+
+class TestChildAgentContextIsolation(unittest.TestCase):
+    def test_child_loads_active_profile_soul_without_ambient_context_or_memory(self):
+        """Render a real child's prompt through active-profile home resolution."""
+        from tempfile import TemporaryDirectory
+
+        with TemporaryDirectory() as temp_dir:
+            root = Path(temp_dir)
+            default_home = root / "hermes-home"
+            active_home = default_home / "profiles" / "active"
+            workspace = root / "workspace"
+            active_memories = active_home / "memories"
+            active_memories.mkdir(parents=True)
+            workspace.mkdir()
+
+            active_soul = "ACTIVE PROFILE DELEGATED SOUL"
+            ambient_soul = "AMBIENT DEFAULT SOUL MUST NOT LEAK"
+            ambient_context = "AMBIENT CONTEXT MUST NOT LEAK"
+            memory_marker = "PERSISTENT MEMORY MUST STAY DISABLED"
+            (active_home / "SOUL.md").write_text(active_soul, encoding="utf-8")
+            (default_home / "SOUL.md").write_text(ambient_soul, encoding="utf-8")
+            (default_home / "AGENTS.md").write_text(
+                ambient_context, encoding="utf-8"
+            )
+            (active_home / "config.yaml").write_text(
+                "memory:\n  memory_enabled: true\n", encoding="utf-8"
+            )
+            (active_memories / "MEMORY.md").write_text(
+                memory_marker, encoding="utf-8"
+            )
+
+            parent = _make_mock_parent()
+            parent.enabled_toolsets = ["terminal"]
+            parent.disabled_toolsets = []
+            parent.client = None
+            parent.prefill_messages = None
+            parent._fallback_chain = None
+            parent.reasoning_config = None
+            parent.request_overrides = {}
+            parent.max_tokens = None
+            parent.acp_command = None
+            parent.acp_args = []
+            parent.session_id = None
+            parent._current_turn_id = ""
+            parent.providers_allowed = None
+            parent.providers_ignored = None
+            parent.providers_order = None
+            parent.provider_sort = None
+            parent.provider_require_parameters = False
+            parent.provider_data_collection = ""
+            parent.openrouter_min_coding_score = None
+            parent._session_db = types.SimpleNamespace(
+                db_path=active_home / "state.db"
+            )
+
+            tool_defs = [{
+                "type": "function",
+                "function": {
+                    "name": "terminal",
+                    "description": "terminal tool",
+                    "parameters": {"type": "object", "properties": {}},
+                },
+            }]
+            child = None
+            with (
+                patch.dict(
+                    os.environ,
+                    {
+                        "HERMES_HOME": str(default_home),
+                        "TERMINAL_CWD": str(workspace),
+                    },
+                ),
+                patch("model_tools.get_tool_definitions", return_value=tool_defs),
+                patch("model_tools.check_toolset_requirements", return_value={}),
+                patch("agent.process_bootstrap.OpenAI"),
+            ):
+                try:
+                    child = _build_child_agent(
+                        task_index=0,
+                        goal="Inspect safely",
+                        context=None,
+                        toolsets=None,
+                        model=None,
+                        max_iterations=10,
+                        parent_agent=parent,
+                        task_count=1,
+                        role="leaf",
+                    )
+                    prompt = child._build_system_prompt()
+                finally:
+                    if child is not None:
+                        child.close()
+
+            self.assertIsNotNone(child)
+            child_state = vars(child)
+            self.assertTrue(child_state["load_soul_identity"])
+            self.assertTrue(child_state["skip_context_files"])
+            self.assertIsNone(child_state["_memory_store"])
+            self.assertIsNone(child_state["_memory_manager"])
+            self.assertIn(active_soul, prompt)
+            self.assertEqual(prompt.count(active_soul), 1)
+            self.assertNotIn(ambient_soul, prompt)
+            self.assertNotIn(ambient_context, prompt)
+            self.assertNotIn(memory_marker, prompt)
+
+
 class TestStripBlockedTools(unittest.TestCase):
     def test_removes_blocked_toolsets(self):
         result = _strip_blocked_tools(["terminal", "file", "delegation", "clarify", "memory", "code_execution"])
@@ -414,7 +521,7 @@ def test_child_dedicated_db_follows_parents_db_path(self):
                 self.assertIsInstance(child_db, SessionDB)
                 self.assertIsNot(child_db, parent_db)
                 self.assertEqual(
-                    str(child_db.db_path), str(parent_db.db_path)
+                    Path(child_db.db_path).resolve(), Path(parent_db.db_path).resolve()
                 )
             finally:
                 if child_db is not None:

tools/delegate_tool.py

@@ -235,7 +235,12 @@ def _build_child_agent(
                 **rt, max_iterations=max_iterations, prefill_messages=getattr(parent_agent, "prefill_messages", None),
                 enabled_toolsets=child_toolsets, disabled_toolsets=child_disabled_toolsets, quiet_mode=True,
                 ephemeral_system_prompt=child_prompt, log_prefix=f"[subagent-{task_index}]", platform="subagent",
-                skip_context_files=True, skip_memory=True, clarify_callback=None,
+                skip_context_files=True,
+                # Keep only the active profile's persona: project context and
+                # memory remain isolated. This adds SOUL.md to the child's
+                # cached prompt (and therefore to its configured provider),
+                # but does not add a model call.
+                load_soul_identity=True, skip_memory=True, clarify_callback=None,
                 thinking_callback=(
                     (lambda text: _safe_progress(child_progress_cb, "_thinking", text) if text else None)
                     if child_progress_cb else None