diff --git a/think/cortex.py b/think/cortex.py
index 5171c1fc7..d9205cd05 100644
--- a/think/cortex.py
+++ b/think/cortex.py
@@ -20,6 +20,7 @@ from __future__ import annotations
 import json
 import logging
 import os
+import signal
 import subprocess
 import sys
 import threading
@@ -58,16 +59,34 @@ class TalentProcess:
 
         if self.process.poll() is None:
             # First try SIGTERM for graceful shutdown
-            self.process.terminate()
+            try:
+                self.process.terminate()
+            except ProcessLookupError:
+                pass
+            self._signal_process_group(signal.SIGTERM)
             try:
                 self.process.wait(timeout=10)  # Give more time for graceful shutdown
             except subprocess.TimeoutExpired:
                 logging.getLogger(__name__).warning(
                     f"Talent {self.use_id} didn't stop gracefully, killing"
                 )
-                self.process.kill()
+                self._signal_process_group(signal.SIGKILL)
+                try:
+                    self.process.kill()
+                except ProcessLookupError:
+                    pass
                 self.process.wait()  # Ensure zombie is reaped
 
+    def _signal_process_group(self, sig: int) -> None:
+        try:
+            pgid = os.getpgid(self.process.pid)
+        except ProcessLookupError:
+            return
+        try:
+            os.killpg(pgid, sig)
+        except ProcessLookupError:
+            return
+
 
 class CortexService:
     """Callosum-based talent process manager."""
@@ -321,6 +340,7 @@ class CortexService:
                 env=env,
                 bufsize=1,
                 cwd=subprocess_cwd,
+                start_new_session=True,
             )
 
             # Send input and close stdin
diff --git a/think/talents.py b/think/talents.py
index 5696820ad..1e3b597cc 100644
--- a/think/talents.py
+++ b/think/talents.py
@@ -18,6 +18,7 @@ import asyncio
 import json
 import logging
 import os
+import signal
 import sys
 import traceback
 from datetime import datetime
@@ -1239,6 +1240,16 @@ async def main_async() -> None:
 
     app_logger = setup_logging(args.verbose)
     event_writer = JSONEventWriter(None)
+    loop = asyncio.get_running_loop()
+    main_task = asyncio.current_task()
+    registered_signals: list[signal.Signals] = []
+    if main_task:
+        for sig in (signal.SIGTERM, signal.SIGINT):
+            try:
+                loop.add_signal_handler(sig, main_task.cancel)
+                registered_signals.append(sig)
+            except (NotImplementedError, RuntimeError):
+                LOG.debug("Signal handler registration unavailable for %s", sig)
 
     def emit_event(data: Event) -> None:
         if "ts" not in data:
@@ -1301,6 +1312,8 @@ async def main_async() -> None:
             emit_event(err)
         raise
     finally:
+        for sig in registered_signals:
+            loop.remove_signal_handler(sig)
         event_writer.close()