From 4e89c53082b13b71d0c7f2f662cd65ea80d9f17c Mon Sep 17 00:00:00 2001
From: Teknium <127238744+teknium1@users.noreply.github.com>
Date: Fri, 15 May 2026 14:00:01 -0700
Subject: [PATCH] fix(async): close unscheduled coroutines in all threadsafe
 bridges (#26584)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Wraps every sync->async coroutine-scheduling site in the codebase with a
new agent.async_utils.safe_schedule_threadsafe() helper that closes the
coroutine on scheduling failure (closed loop, shutdown race, etc.)
instead of leaking it as 'coroutine was never awaited' RuntimeWarnings
plus reference leaks.

22 production call sites migrated across the codebase:
- acp_adapter/events.py, acp_adapter/permissions.py
- agent/lsp/manager.py
- cron/scheduler.py (media + text delivery paths)
- gateway/platforms/feishu.py (5 sites, via existing _submit_on_loop helper
  which now delegates to safe_schedule_threadsafe)
- gateway/run.py (10 sites: telegram rename, agent:step hook, status
  callback, interim+bg-review, clarify send, exec-approval button+text,
  temp-bubble cleanup, channel-directory refresh)
- plugins/memory/hindsight, plugins/platforms/google_chat
- tools/browser_supervisor.py (3), browser_cdp_tool.py,
  computer_use/cua_backend.py, slash_confirm.py
- tools/environments/modal.py (_AsyncWorker)
- tools/mcp_tool.py (2 + 8 _run_on_mcp_loop callers converted to
  factory-style so the coroutine is never constructed on a dead loop)
- tui_gateway/ws.py

Tests: new tests/agent/test_async_utils.py covers helper behavior under
live loop, dead loop, None loop, and scheduling exceptions. Regression
tests added at three PR-original sites (acp events, acp permissions,
mcp loop runner) mirroring contributor's intent.

Live-tested end-to-end:
- Helper stress test: 1500 schedules across live/dead/race scenarios,
  zero leaked coroutines
- Race exercised: 5000 schedules with loop killed mid-flight, 100 ok /
  4900 None returns, zero leaks
- hermes chat -q with terminal tool call (exercises step_callback bridge)
- MCP probe against failing subprocess servers + factory path
- Real gateway daemon boot + SIGINT shutdown across multiple platform
  adapter inits
- WSTransport 100 live + 50 dead-loop writes
- Cron delivery path live + dead loop

Salvages PR #2657 — adopts contributor's intent over a much wider site
list and a single centralized helper instead of inline try/except at
each site. 3 of the original PR's 6 sites no longer exist on main
(environments/patches.py deleted, DingTalk refactored to native async);
the equivalent fix lives in tools/environments/modal.py instead.

Co-authored-by: JithendraNara <jithendranaidunara@gmail.com>
---
 acp_adapter/events.py                      |  13 +-
 acp_adapter/permissions.py                 |  27 ++-
 agent/async_utils.py                       |  68 +++++++
 agent/lsp/manager.py                       |   7 +-
 cron/scheduler.py                          |  39 ++--
 gateway/platforms/feishu.py                |  44 ++---
 gateway/run.py                             | 206 ++++++++++++---------
 plugins/memory/hindsight/__init__.py       |   5 +-
 plugins/platforms/google_chat/adapter.py   |  10 +-
 scripts/release.py                         |   1 +
 tests/acp/test_events.py                   |  46 +++++
 tests/acp/test_permissions.py              |  49 ++++-
 tests/agent/test_async_utils.py            | 157 ++++++++++++++++
 tests/tools/test_mcp_probe.py              |  12 +-
 tests/tools/test_mcp_structured_content.py |   3 +-
 tests/tools/test_mcp_tool.py               |  80 +++++++-
 tools/browser_cdp_tool.py                  |   8 +-
 tools/browser_supervisor.py                |  22 ++-
 tools/computer_use/cua_backend.py          |   7 +-
 tools/environments/modal.py                |   7 +-
 tools/mcp_tool.py                          |  52 ++++--
 tools/slash_confirm.py                     |   7 +-
 tui_gateway/ws.py                          |   6 +-
 23 files changed, 690 insertions(+), 186 deletions(-)
 create mode 100644 agent/async_utils.py
 create mode 100644 tests/agent/test_async_utils.py

diff --git a/acp_adapter/events.py b/acp_adapter/events.py
index 1257f902ebb..f0442ca2e8f 100644
--- a/acp_adapter/events.py
+++ b/acp_adapter/events.py
@@ -31,10 +31,17 @@ def _send_update(
     update: Any,
 ) -> None:
     """Fire-and-forget an ACP session update from a worker thread."""
+    from agent.async_utils import safe_schedule_threadsafe
+
+    future = safe_schedule_threadsafe(
+        conn.session_update(session_id, update),
+        loop,
+        logger=logger,
+        log_message="Failed to send ACP update",
+    )
+    if future is None:
+        return
     try:
-        future = asyncio.run_coroutine_threadsafe(
-            conn.session_update(session_id, update), loop
-        )
         future.result(timeout=5)
     except Exception:
         logger.debug("Failed to send ACP update", exc_info=True)
diff --git a/acp_adapter/permissions.py b/acp_adapter/permissions.py
index 44aead28742..76474e55dac 100644
--- a/acp_adapter/permissions.py
+++ b/acp_adapter/permissions.py
@@ -111,21 +111,28 @@ def make_approval_callback(
         allow_permanent: bool = True,
         **_: object,
     ) -> str:
+        from agent.async_utils import safe_schedule_threadsafe
+
         options = _build_permission_options(allow_permanent=allow_permanent)
 
-        future = None
+        tool_call = _build_permission_tool_call(command, description)
+        coro = request_permission_fn(
+            session_id=session_id,
+            tool_call=tool_call,
+            options=options,
+        )
+        future = safe_schedule_threadsafe(
+            coro, loop,
+            logger=logger,
+            log_message="Permission request: failed to schedule on loop",
+        )
+        if future is None:
+            return "deny"
+
         try:
-            tool_call = _build_permission_tool_call(command, description)
-            coro = request_permission_fn(
-                session_id=session_id,
-                tool_call=tool_call,
-                options=options,
-            )
-            future = asyncio.run_coroutine_threadsafe(coro, loop)
             response = future.result(timeout=timeout)
         except (FutureTimeout, Exception) as exc:
-            if future is not None:
-                future.cancel()
+            future.cancel()
             logger.warning("Permission request timed out or failed: %s", exc)
             return "deny"
 
diff --git a/agent/async_utils.py b/agent/async_utils.py
new file mode 100644
index 00000000000..d268e1a3a84
--- /dev/null
+++ b/agent/async_utils.py
@@ -0,0 +1,68 @@
+"""Async/sync bridging helpers.
+
+The codebase has ~30 sites that schedule a coroutine onto an event loop from a
+worker thread via :func:`asyncio.run_coroutine_threadsafe`.  That function can
+raise :class:`RuntimeError` (e.g. the loop was closed during a shutdown race),
+and when it does the coroutine object is never awaited and never closed —
+which triggers a ``"coroutine '<name>' was never awaited"`` RuntimeWarning and
+leaks the coroutine's frame until GC.
+
+:func:`safe_schedule_threadsafe` wraps the call, closes the coroutine on
+scheduling failure, and returns ``None`` (instead of a half-formed future) so
+callers can branch cleanly:
+
+    fut = safe_schedule_threadsafe(coro, loop)
+    if fut is None:
+        return  # or fallback behavior
+    fut.result(timeout=5)
+
+The helper deliberately does NOT also handle ``future.result()`` failures —
+that is a separate concern.  Once the loop has accepted the coroutine, its
+lifecycle belongs to the loop, not the scheduling thread.
+"""
+from __future__ import annotations
+
+import asyncio
+import logging
+from concurrent.futures import Future
+from typing import Any, Coroutine, Optional
+
+
+_DEFAULT_LOGGER = logging.getLogger(__name__)
+
+
+def safe_schedule_threadsafe(
+    coro: Coroutine[Any, Any, Any],
+    loop: Optional[asyncio.AbstractEventLoop],
+    *,
+    logger: Optional[logging.Logger] = None,
+    log_message: str = "Failed to schedule coroutine on loop",
+    log_level: int = logging.DEBUG,
+) -> Optional[Future]:
+    """Schedule ``coro`` on ``loop`` from a sync context, leak-safe.
+
+    Returns the :class:`concurrent.futures.Future` on success, or ``None`` if
+    the loop is missing or :func:`asyncio.run_coroutine_threadsafe` raised
+    (e.g. the loop was closed during a shutdown race).  In all failure paths
+    the coroutine is :meth:`close`-d so it does not trigger
+    ``"coroutine was never awaited"`` warnings or leak its frame.
+
+    Callers retain full control over what to do with the returned future
+    (call ``.result(timeout=...)``, attach ``add_done_callback``, ignore it
+    fire-and-forget, etc.).
+    """
+    log = logger if logger is not None else _DEFAULT_LOGGER
+
+    if loop is None:
+        if asyncio.iscoroutine(coro):
+            coro.close()
+        log.log(log_level, "%s: loop is None", log_message)
+        return None
+
+    try:
+        return asyncio.run_coroutine_threadsafe(coro, loop)
+    except Exception as exc:
+        if asyncio.iscoroutine(coro):
+            coro.close()
+        log.log(log_level, "%s: %s", log_message, exc)
+        return None
diff --git a/agent/lsp/manager.py b/agent/lsp/manager.py
index 34c0b0ba92b..7f5feaa170f 100644
--- a/agent/lsp/manager.py
+++ b/agent/lsp/manager.py
@@ -107,9 +107,14 @@ class _BackgroundLoop:
 
         Returns the coroutine's result, or raises its exception.
         """
+        from agent.async_utils import safe_schedule_threadsafe
         if self._loop is None:
+            if asyncio.iscoroutine(coro):
+                coro.close()
             raise RuntimeError("background loop not started")
-        fut: ConcurrentFuture = asyncio.run_coroutine_threadsafe(coro, self._loop)
+        fut = safe_schedule_threadsafe(coro, self._loop)
+        if fut is None:
+            raise RuntimeError("background loop not running")
         try:
             return fut.result(timeout=timeout)
         except Exception:
diff --git a/cron/scheduler.py b/cron/scheduler.py
index b585ef2e42b..d470e8c2c74 100644
--- a/cron/scheduler.py
+++ b/cron/scheduler.py
@@ -464,7 +464,14 @@ def _send_media_via_adapter(
             else:
                 coro = adapter.send_document(chat_id=chat_id, file_path=media_path, metadata=metadata)
 
-            future = asyncio.run_coroutine_threadsafe(coro, loop)
+            from agent.async_utils import safe_schedule_threadsafe
+            future = safe_schedule_threadsafe(coro, loop)
+            if future is None:
+                logger.warning(
+                    "Job '%s': cannot send media %s, gateway loop unavailable",
+                    job.get("id", "?"), media_path,
+                )
+                return
             try:
                 result = future.result(timeout=30)
             except TimeoutError:
@@ -585,22 +592,26 @@ def _deliver_result(job: dict, content: str, adapters=None, loop=None) -> Option
                 text_to_send = cleaned_delivery_content.strip()
                 adapter_ok = True
                 if text_to_send:
-                    future = asyncio.run_coroutine_threadsafe(
+                    from agent.async_utils import safe_schedule_threadsafe
+                    future = safe_schedule_threadsafe(
                         runtime_adapter.send(chat_id, text_to_send, metadata=send_metadata),
                         loop,
                     )
-                    try:
-                        send_result = future.result(timeout=60)
-                    except TimeoutError:
-                        future.cancel()
-                        raise
-                    if send_result and not getattr(send_result, "success", True):
-                        err = getattr(send_result, "error", "unknown")
-                        logger.warning(
-                            "Job '%s': live adapter send to %s:%s failed (%s), falling back to standalone",
-                            job["id"], platform_name, chat_id, err,
-                        )
-                        adapter_ok = False  # fall through to standalone path
+                    if future is None:
+                        adapter_ok = False
+                    else:
+                        try:
+                            send_result = future.result(timeout=60)
+                        except TimeoutError:
+                            future.cancel()
+                            raise
+                        if send_result and not getattr(send_result, "success", True):
+                            err = getattr(send_result, "error", "unknown")
+                            logger.warning(
+                                "Job '%s': live adapter send to %s:%s failed (%s), falling back to standalone",
+                                job["id"], platform_name, chat_id, err,
+                            )
+                            adapter_ok = False  # fall through to standalone path
 
                 # Send extracted media files as native attachments via the live adapter
                 if adapter_ok and media_files:
diff --git a/gateway/platforms/feishu.py b/gateway/platforms/feishu.py
index 8d60046d35d..a9b0447080d 100644
--- a/gateway/platforms/feishu.py
+++ b/gateway/platforms/feishu.py
@@ -2273,11 +2273,7 @@ class FeishuAdapter(BasePlatformAdapter):
                     daemon=True,
                 ).start()
             return
-        future = asyncio.run_coroutine_threadsafe(
-            self._handle_message_event_data(data),
-            loop,
-        )
-        future.add_done_callback(self._log_background_failure)
+        self._submit_on_loop(loop, self._handle_message_event_data(data))
 
     def _enqueue_pending_inbound_event(self, data: Any) -> bool:
         """Append an event to the pending-inbound queue.
@@ -2353,16 +2349,12 @@ class FeishuAdapter(BasePlatformAdapter):
                     dispatched = 0
                     requeue: List[Any] = []
                     for event in batch:
-                        try:
-                            fut = asyncio.run_coroutine_threadsafe(
-                                self._handle_message_event_data(event),
-                                loop,
-                            )
-                            fut.add_done_callback(self._log_background_failure)
+                        if self._submit_on_loop(
+                            loop, self._handle_message_event_data(event)
+                        ):
                             dispatched += 1
-                        except RuntimeError:
-                            # Loop closed between check and submit — requeue
-                            # and poll again.
+                        else:
+                            # Loop closed/unavailable — requeue and poll again.
                             requeue.append(event)
                     if requeue:
                         with self._pending_inbound_lock:
@@ -2466,11 +2458,10 @@ class FeishuAdapter(BasePlatformAdapter):
         if not self._loop_accepts_callbacks(loop):
             logger.warning("[Feishu] Dropping drive comment event before adapter loop is ready")
             return
-        future = asyncio.run_coroutine_threadsafe(
-            handle_drive_comment_event(self._client, data, self_open_id=self._bot_open_id),
+        self._submit_on_loop(
             loop,
+            handle_drive_comment_event(self._client, data, self_open_id=self._bot_open_id),
         )
-        future.add_done_callback(self._log_background_failure)
 
     def _on_reaction_event(self, event_type: str, data: Any) -> None:
         """Route user reactions on bot messages as synthetic text events."""
@@ -2498,11 +2489,7 @@ class FeishuAdapter(BasePlatformAdapter):
             or bool(getattr(loop, "is_closed", lambda: False)())
         ):
             return
-        future = asyncio.run_coroutine_threadsafe(
-            self._handle_reaction_event(event_type, data),
-            loop,
-        )
-        future.add_done_callback(self._log_background_failure)
+        self._submit_on_loop(loop, self._handle_reaction_event(event_type, data))
 
     def _on_card_action_trigger(self, data: Any) -> Any:
         """Handle card-action callback from the Feishu SDK (synchronous).
@@ -2548,11 +2535,14 @@ class FeishuAdapter(BasePlatformAdapter):
 
     def _submit_on_loop(self, loop: Any, coro: Any) -> bool:
         """Schedule background work on the adapter loop with shared failure logging."""
-        try:
-            future = asyncio.run_coroutine_threadsafe(coro, loop)
-        except Exception:
-            coro.close()
-            logger.warning("[Feishu] Failed to schedule background callback work", exc_info=True)
+        from agent.async_utils import safe_schedule_threadsafe
+        future = safe_schedule_threadsafe(
+            coro, loop,
+            logger=logger,
+            log_message="[Feishu] Failed to schedule background callback work",
+            log_level=logging.WARNING,
+        )
+        if future is None:
             return False
         future.add_done_callback(self._log_background_failure)
         return True
diff --git a/gateway/run.py b/gateway/run.py
index 5e8fce8e18d..f41357673f7 100644
--- a/gateway/run.py
+++ b/gateway/run.py
@@ -50,6 +50,7 @@ from typing import Dict, Optional, Any, List, Union
 # gateway is a long-running daemon, so its boot cost matters less than
 # preserving the established test-patch surface.
 from agent.account_usage import fetch_account_usage, render_account_usage_lines
+from agent.async_utils import safe_schedule_threadsafe
 from agent.i18n import t
 from hermes_cli.config import cfg_get
 
@@ -11217,10 +11218,14 @@ class GatewayRunner:
             copied_source = dataclasses.replace(source)
         except Exception:
             copied_source = source
-        future = asyncio.run_coroutine_threadsafe(
+        future = safe_schedule_threadsafe(
             self._rename_telegram_topic_for_session_title(copied_source, session_id, title),
             loop,
+            logger=logger,
+            log_message="Telegram topic title rename failed to schedule",
         )
+        if future is None:
+            return
         def _log_rename_failure(fut) -> None:
             try:
                 fut.result()
@@ -14810,29 +14815,28 @@ class GatewayRunner:
         def _step_callback_sync(iteration: int, prev_tools: list) -> None:
             if not _run_still_current():
                 return
-            try:
-                # prev_tools may be list[str] or list[dict] with "name"/"result"
-                # keys.  Normalise to keep "tool_names" backward-compatible for
-                # user-authored hooks that do ', '.join(tool_names)'.
-                _names: list[str] = []
-                for _t in (prev_tools or []):
-                    if isinstance(_t, dict):
-                        _names.append(_t.get("name") or "")
-                    else:
-                        _names.append(str(_t))
-                asyncio.run_coroutine_threadsafe(
-                    _hooks_ref.emit("agent:step", {
-                        "platform": source.platform.value if source.platform else "",
-                        "user_id": source.user_id,
-                        "session_id": session_id,
-                        "iteration": iteration,
-                        "tool_names": _names,
-                        "tools": prev_tools,
-                    }),
-                    _loop_for_step,
-                )
-            except Exception as _e:
-                logger.debug("agent:step hook error: %s", _e)
+            # prev_tools may be list[str] or list[dict] with "name"/"result"
+            # keys.  Normalise to keep "tool_names" backward-compatible for
+            # user-authored hooks that do ', '.join(tool_names)'.
+            _names: list[str] = []
+            for _t in (prev_tools or []):
+                if isinstance(_t, dict):
+                    _names.append(_t.get("name") or "")
+                else:
+                    _names.append(str(_t))
+            safe_schedule_threadsafe(
+                _hooks_ref.emit("agent:step", {
+                    "platform": source.platform.value if source.platform else "",
+                    "user_id": source.user_id,
+                    "session_id": session_id,
+                    "iteration": iteration,
+                    "tool_names": _names,
+                    "tools": prev_tools,
+                }),
+                _loop_for_step,
+                logger=logger,
+                log_message="agent:step hook scheduling error",
+            )
 
         # Bridge sync status_callback → async adapter.send for context pressure
         _status_adapter = self.adapters.get(source.platform)
@@ -14852,27 +14856,28 @@ class GatewayRunner:
         def _status_callback_sync(event_type: str, message: str) -> None:
             if not _status_adapter or not _run_still_current():
                 return
-            try:
-                _fut = asyncio.run_coroutine_threadsafe(
-                    _status_adapter.send(
-                        _status_chat_id,
-                        message,
-                        metadata=_status_thread_metadata,
-                    ),
-                    _loop_for_step,
-                )
-                if _cleanup_progress:
-                    def _track_status_id(fut) -> None:
-                        try:
-                            res = fut.result()
-                        except Exception:
-                            return
-                        mid = getattr(res, "message_id", None)
-                        if getattr(res, "success", False) and mid:
-                            _cleanup_msg_ids.append(str(mid))
-                    _fut.add_done_callback(_track_status_id)
-            except Exception as _e:
-                logger.debug("status_callback error (%s): %s", event_type, _e)
+            _fut = safe_schedule_threadsafe(
+                _status_adapter.send(
+                    _status_chat_id,
+                    message,
+                    metadata=_status_thread_metadata,
+                ),
+                _loop_for_step,
+                logger=logger,
+                log_message=f"status_callback ({event_type}) scheduling error",
+            )
+            if _fut is None:
+                return
+            if _cleanup_progress:
+                def _track_status_id(fut) -> None:
+                    try:
+                        res = fut.result()
+                    except Exception:
+                        return
+                    mid = getattr(res, "message_id", None)
+                    if getattr(res, "success", False) and mid:
+                        _cleanup_msg_ids.append(str(mid))
+                _fut.add_done_callback(_track_status_id)
 
         def run_sync():
             # The conditional re-assignment of `message` further below
@@ -15026,17 +15031,16 @@ class GatewayRunner:
                     return
                 if already_streamed or not _status_adapter or not str(text or "").strip():
                     return
-                try:
-                    asyncio.run_coroutine_threadsafe(
-                        _status_adapter.send(
-                            _status_chat_id,
-                            text,
-                            metadata=_status_thread_metadata,
-                        ),
-                        _loop_for_step,
-                    )
-                except Exception as _e:
-                    logger.debug("interim_assistant_callback error: %s", _e)
+                safe_schedule_threadsafe(
+                    _status_adapter.send(
+                        _status_chat_id,
+                        text,
+                        metadata=_status_thread_metadata,
+                    ),
+                    _loop_for_step,
+                    logger=logger,
+                    log_message="interim_assistant_callback scheduling error",
+                )
 
             turn_route = self._resolve_turn_agent_config(message, model, runtime_kwargs)
 
@@ -15125,17 +15129,16 @@ class GatewayRunner:
             def _deliver_bg_review_message(message: str) -> None:
                 if not _status_adapter or not _run_still_current():
                     return
-                try:
-                    asyncio.run_coroutine_threadsafe(
-                        _status_adapter.send(
-                            _status_chat_id,
-                            message,
-                            metadata=_status_thread_metadata,
-                        ),
-                        _loop_for_step,
-                    )
-                except Exception as _e:
-                    logger.debug("background_review_callback error: %s", _e)
+                safe_schedule_threadsafe(
+                    _status_adapter.send(
+                        _status_chat_id,
+                        message,
+                        metadata=_status_thread_metadata,
+                    ),
+                    _loop_for_step,
+                    logger=logger,
+                    log_message="background_review_callback scheduling error",
+                )
 
             def _release_bg_review_messages() -> None:
                 _bg_review_release.set()
@@ -15207,23 +15210,28 @@ class GatewayRunner:
                     pass
 
                 send_ok = False
-                try:
-                    fut = asyncio.run_coroutine_threadsafe(
-                        _status_adapter.send_clarify(
-                            chat_id=_status_chat_id,
-                            question=question,
-                            choices=list(choices) if choices else None,
-                            clarify_id=clarify_id,
-                            session_key=session_key or "",
-                            metadata=_status_thread_metadata,
-                        ),
-                        _loop_for_step,
-                    )
-                    result = fut.result(timeout=15)
-                    send_ok = bool(getattr(result, "success", False))
-                except Exception as exc:
-                    logger.warning("Clarify send failed: %s", exc)
+                fut = safe_schedule_threadsafe(
+                    _status_adapter.send_clarify(
+                        chat_id=_status_chat_id,
+                        question=question,
+                        choices=list(choices) if choices else None,
+                        clarify_id=clarify_id,
+                        session_key=session_key or "",
+                        metadata=_status_thread_metadata,
+                    ),
+                    _loop_for_step,
+                    logger=logger,
+                    log_message="Clarify send failed to schedule",
+                )
+                if fut is None:
                     send_ok = False
+                else:
+                    try:
+                        result = fut.result(timeout=15)
+                        send_ok = bool(getattr(result, "success", False))
+                    except Exception as exc:
+                        logger.warning("Clarify send failed: %s", exc)
+                        send_ok = False
 
                 if not send_ok:
                     # Couldn't deliver the prompt — clean up and return
@@ -15343,7 +15351,7 @@ class GatewayRunner:
                 # false positives from MagicMock auto-attribute creation in tests.
                 if getattr(type(_status_adapter), "send_exec_approval", None) is not None:
                     try:
-                        _approval_result = asyncio.run_coroutine_threadsafe(
+                        _approval_fut = safe_schedule_threadsafe(
                             _status_adapter.send_exec_approval(
                                 chat_id=_status_chat_id,
                                 command=cmd,
@@ -15352,7 +15360,12 @@ class GatewayRunner:
                                 metadata=_status_thread_metadata,
                             ),
                             _loop_for_step,
-                        ).result(timeout=15)
+                            logger=logger,
+                            log_message="send_exec_approval scheduling error",
+                        )
+                        if _approval_fut is None:
+                            raise RuntimeError("send_exec_approval: loop unavailable")
+                        _approval_result = _approval_fut.result(timeout=15)
                         if _approval_result.success:
                             return
                         logger.warning(
@@ -15374,14 +15387,18 @@ class GatewayRunner:
                     f"for the session, `/approve always` to approve permanently, or `/deny` to cancel."
                 )
                 try:
-                    asyncio.run_coroutine_threadsafe(
+                    _approval_send_fut = safe_schedule_threadsafe(
                         _status_adapter.send(
                             _status_chat_id,
                             msg,
                             metadata=_status_thread_metadata,
                         ),
                         _loop_for_step,
-                    ).result(timeout=15)
+                        logger=logger,
+                        log_message="Approval text-send scheduling error",
+                    )
+                    if _approval_send_fut is not None:
+                        _approval_send_fut.result(timeout=15)
                 except Exception as _e:
                     logger.error("Failed to send approval request: %s", _e)
 
@@ -16343,7 +16360,11 @@ class GatewayRunner:
                         except Exception:
                             pass
                 try:
-                    asyncio.run_coroutine_threadsafe(_delete_all(), _loop_snapshot)
+                    safe_schedule_threadsafe(
+                        _delete_all(), _loop_snapshot,
+                        logger=logger,
+                        log_message="Temp bubble cleanup scheduling error",
+                    )
                 except Exception:
                     pass
 
@@ -16400,10 +16421,13 @@ def _start_cron_ticker(stop_event: threading.Event, adapters=None, loop=None, in
                     # this ticker runs in a background thread. Schedule onto
                     # the gateway event loop and wait briefly for completion
                     # so refresh failures are still logged via the except.
-                    fut = asyncio.run_coroutine_threadsafe(
-                        build_channel_directory(adapters), loop
+                    fut = safe_schedule_threadsafe(
+                        build_channel_directory(adapters), loop,
+                        logger=logger,
+                        log_message="Channel directory refresh scheduling error",
                     )
-                    fut.result(timeout=30)
+                    if fut is not None:
+                        fut.result(timeout=30)
             except Exception as e:
                 logger.debug("Channel directory refresh error: %s", e)
 
diff --git a/plugins/memory/hindsight/__init__.py b/plugins/memory/hindsight/__init__.py
index 3a42a320453..52b1ac247f1 100644
--- a/plugins/memory/hindsight/__init__.py
+++ b/plugins/memory/hindsight/__init__.py
@@ -221,8 +221,11 @@ def _get_loop() -> asyncio.AbstractEventLoop:
 
 def _run_sync(coro, timeout: float = _DEFAULT_TIMEOUT):
     """Schedule *coro* on the shared loop and block until done."""
+    from agent.async_utils import safe_schedule_threadsafe
     loop = _get_loop()
-    future = asyncio.run_coroutine_threadsafe(coro, loop)
+    future = safe_schedule_threadsafe(coro, loop)
+    if future is None:
+        raise RuntimeError("Hindsight loop unavailable")
     return future.result(timeout=timeout)
 
 
diff --git a/plugins/platforms/google_chat/adapter.py b/plugins/platforms/google_chat/adapter.py
index 1d58e801f46..d8777bf7101 100644
--- a/plugins/platforms/google_chat/adapter.py
+++ b/plugins/platforms/google_chat/adapter.py
@@ -670,10 +670,18 @@ class GoogleChatAdapter(BasePlatformAdapter):
             logger.warning("[GoogleChat] Loop not accepting callbacks; dropping event")
             return
         try:
-            future = asyncio.run_coroutine_threadsafe(coro, loop)
+            from agent.async_utils import safe_schedule_threadsafe
+            future = safe_schedule_threadsafe(
+                coro, loop,
+                logger=logger,
+                log_message="[GoogleChat] Failed to schedule background callback",
+                log_level=logging.WARNING,
+            )
         except RuntimeError:
             logger.warning("[GoogleChat] Loop closed between check and submit")
             return
+        if future is None:
+            return
         future.add_done_callback(self._log_background_failure)
 
     # ------------------------------------------------------------------
diff --git a/scripts/release.py b/scripts/release.py
index 740b79091b1..c9cd9c173c0 100755
--- a/scripts/release.py
+++ b/scripts/release.py
@@ -62,6 +62,7 @@ AUTHOR_MAP = {
     "nidhi2894@gmail.com": "nidhi-singh02",
     "30312689+aashizpoudel@users.noreply.github.com": "aashizpoudel",
     "oleksii.lisikh@gmail.com": "olisikh",
+    "jithendranaidunara@gmail.com": "JithendraNara",
     "jeremy@geocaching.com": "outdoorsea",
     "leone.parise@gmail.com": "leoneparise",
     "mr@shu.io": "mrshu",
diff --git a/tests/acp/test_events.py b/tests/acp/test_events.py
index c9f91a181ed..56a2687226c 100644
--- a/tests/acp/test_events.py
+++ b/tests/acp/test_events.py
@@ -1,6 +1,8 @@
 """Tests for acp_adapter.events — callback factories for ACP notifications."""
 
 import asyncio
+import gc
+import warnings
 from concurrent.futures import Future
 from unittest.mock import AsyncMock, MagicMock, patch
 
@@ -10,6 +12,7 @@ import acp
 from acp.schema import ToolCallStart, ToolCallProgress, AgentThoughtChunk, AgentMessageChunk
 
 from acp_adapter.events import (
+    _send_update,
     make_message_cb,
     make_step_cb,
     make_thinking_cb,
@@ -325,3 +328,46 @@ class TestMessageCallback:
             cb("")
 
         mock_rcts.assert_not_called()
+
+
+# ---------------------------------------------------------------------------
+# Scheduler-failure regression
+# ---------------------------------------------------------------------------
+
+class TestSendUpdate:
+    def test_scheduler_failure_closes_update_coroutine(self, event_loop_fixture):
+        """If run_coroutine_threadsafe raises, _send_update must close the coro."""
+        created = {"coro": None}
+
+        async def _session_update(session_id, update):
+            return None
+
+        conn = MagicMock()
+
+        def _capture_update(session_id, update):
+            created["coro"] = _session_update(session_id, update)
+            return created["coro"]
+
+        conn.session_update = _capture_update
+
+        with warnings.catch_warnings(record=True) as caught:
+            warnings.simplefilter("always")
+            with patch(
+                "agent.async_utils.asyncio.run_coroutine_threadsafe",
+                side_effect=RuntimeError("scheduler down"),
+            ):
+                _send_update(conn, "session-1", event_loop_fixture, {"type": "noop"})
+            gc.collect()
+
+        assert created["coro"] is not None
+        assert created["coro"].cr_frame is None
+        # Only count warnings about THIS test's coroutine; other tests in the
+        # same xdist worker (or stdlib mock internals) may emit unrelated
+        # "coroutine was never awaited" warnings that bleed through.
+        runtime_warnings = [
+            w for w in caught
+            if issubclass(w.category, RuntimeWarning)
+            and "was never awaited" in str(w.message)
+            and "_session_update" in str(w.message)
+        ]
+        assert runtime_warnings == []
diff --git a/tests/acp/test_permissions.py b/tests/acp/test_permissions.py
index 8bbdeeb392a..b4c121829dc 100644
--- a/tests/acp/test_permissions.py
+++ b/tests/acp/test_permissions.py
@@ -38,7 +38,7 @@ def _invoke_callback(
         scheduled["loop"] = passed_loop
         return future
 
-    with patch("acp_adapter.permissions.asyncio.run_coroutine_threadsafe", side_effect=_schedule):
+    with patch("agent.async_utils.asyncio.run_coroutine_threadsafe", side_effect=_schedule):
         cb = make_approval_callback(request_permission, loop, session_id="s1", timeout=timeout)
         if use_prompt_path:
             result = prompt_dangerous_approval(
@@ -135,7 +135,7 @@ class TestApprovalBridge:
             scheduled["loop"] = passed_loop
             return future
 
-        with patch("acp_adapter.permissions.asyncio.run_coroutine_threadsafe", side_effect=_schedule):
+        with patch("agent.async_utils.asyncio.run_coroutine_threadsafe", side_effect=_schedule):
             cb = make_approval_callback(request_permission, loop, session_id="s1", timeout=0.01)
             result = cb("rm -rf /", "dangerous command")
 
@@ -159,10 +159,53 @@ class TestApprovalBridge:
             scheduled["loop"] = passed_loop
             return future
 
-        with patch("acp_adapter.permissions.asyncio.run_coroutine_threadsafe", side_effect=_schedule):
+        with patch("agent.async_utils.asyncio.run_coroutine_threadsafe", side_effect=_schedule):
             cb = make_approval_callback(request_permission, loop, session_id="s1", timeout=1.0)
             result = cb("echo hi", "demo")
 
         scheduled["coro"].close()
 
         assert result == "deny"
+
+
+# ---------------------------------------------------------------------------
+# Scheduler-failure regression
+# ---------------------------------------------------------------------------
+
+import gc  # noqa: E402
+import warnings  # noqa: E402
+
+
+class TestSchedulerFailure:
+    def test_scheduler_failure_closes_permission_coroutine(self):
+        """If run_coroutine_threadsafe raises, the coro is closed and we return 'deny'."""
+        loop = MagicMock(spec=asyncio.AbstractEventLoop)
+        created = {"coro": None}
+
+        async def _response_coro(**kwargs):
+            return _make_response(AllowedOutcome(option_id="allow_once", outcome="selected"))
+
+        def _request_permission(**kwargs):
+            created["coro"] = _response_coro(**kwargs)
+            return created["coro"]
+
+        with warnings.catch_warnings(record=True) as caught:
+            warnings.simplefilter("always")
+            with patch(
+                "agent.async_utils.asyncio.run_coroutine_threadsafe",
+                side_effect=RuntimeError("scheduler down"),
+            ):
+                cb = make_approval_callback(_request_permission, loop, session_id="s1", timeout=0.01)
+                result = cb("rm -rf /", "dangerous")
+            gc.collect()
+
+        assert result == "deny"
+        assert created["coro"] is not None
+        assert created["coro"].cr_frame is None
+        runtime_warnings = [
+            w for w in caught
+            if issubclass(w.category, RuntimeWarning)
+            and "was never awaited" in str(w.message)
+            and "_response_coro" in str(w.message)
+        ]
+        assert runtime_warnings == []
diff --git a/tests/agent/test_async_utils.py b/tests/agent/test_async_utils.py
new file mode 100644
index 00000000000..33ce84ee0c6
--- /dev/null
+++ b/tests/agent/test_async_utils.py
@@ -0,0 +1,157 @@
+"""Tests for agent.async_utils.safe_schedule_threadsafe."""
+
+from __future__ import annotations
+
+import asyncio
+import gc
+import warnings
+from concurrent.futures import Future
+from unittest.mock import patch
+
+import pytest
+
+from agent.async_utils import safe_schedule_threadsafe
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+def _no_unawaited_warnings(caught, *, coro_name: str = "") -> bool:
+    """Return True if no "X was never awaited" warning slipped through.
+
+    When *coro_name* is provided, only warnings naming that coroutine are
+    counted — xdist workers may emit unrelated unawaited-coroutine warnings
+    (e.g. ``AsyncMockMixin._execute_mock_call``) from concurrent tests.
+    """
+    bad = [
+        w for w in caught
+        if issubclass(w.category, RuntimeWarning)
+        and "was never awaited" in str(w.message)
+        and (not coro_name or coro_name in str(w.message))
+    ]
+    return not bad
+
+
+# ---------------------------------------------------------------------------
+# Tests
+# ---------------------------------------------------------------------------
+
+class TestSafeScheduleThreadsafe:
+    def test_returns_future_on_success(self):
+        loop = asyncio.new_event_loop()
+        try:
+            import threading
+            ready = threading.Event()
+            stop = threading.Event()
+
+            def _runner():
+                asyncio.set_event_loop(loop)
+                ready.set()
+                loop.run_until_complete(_wait_for_stop(stop))
+
+            async def _wait_for_stop(ev):
+                while not ev.is_set():
+                    await asyncio.sleep(0.005)
+
+            t = threading.Thread(target=_runner, daemon=True)
+            t.start()
+            ready.wait(timeout=2)
+
+            async def _sample():
+                return 42
+
+            fut = safe_schedule_threadsafe(_sample(), loop)
+            assert isinstance(fut, Future)
+            assert fut.result(timeout=2) == 42
+
+            stop.set()
+            t.join(timeout=2)
+        finally:
+            if loop.is_running():
+                loop.call_soon_threadsafe(loop.stop)
+            loop.close()
+
+    def test_closed_loop_returns_none_and_closes_coroutine(self):
+        loop = asyncio.new_event_loop()
+        loop.close()
+
+        async def _sample():
+            return "ok"
+
+        coro = _sample()
+        with warnings.catch_warnings(record=True) as caught:
+            warnings.simplefilter("always")
+            result = safe_schedule_threadsafe(coro, loop)
+            del coro
+            gc.collect()
+
+        assert result is None
+        assert _no_unawaited_warnings(caught, coro_name='_sample')
+
+    def test_none_loop_returns_none_and_closes_coroutine(self):
+        async def _sample():
+            return "ok"
+
+        coro = _sample()
+        with warnings.catch_warnings(record=True) as caught:
+            warnings.simplefilter("always")
+            result = safe_schedule_threadsafe(coro, None)
+            del coro
+            gc.collect()
+
+        assert result is None
+        assert _no_unawaited_warnings(caught, coro_name='_sample')
+
+    def test_scheduling_exception_closes_coroutine(self):
+        """If run_coroutine_threadsafe raises, close the coroutine and return None."""
+        # A loop that *looks* open but raises on submission
+        loop = asyncio.new_event_loop()
+        try:
+            async def _sample():
+                return "ok"
+
+            coro = _sample()
+            with warnings.catch_warnings(record=True) as caught:
+                warnings.simplefilter("always")
+                with patch(
+                    "agent.async_utils.asyncio.run_coroutine_threadsafe",
+                    side_effect=RuntimeError("scheduler down"),
+                ):
+                    result = safe_schedule_threadsafe(coro, loop)
+                del coro
+                gc.collect()
+
+            assert result is None
+            assert _no_unawaited_warnings(caught, coro_name='_sample')
+        finally:
+            loop.close()
+
+    def test_logs_at_specified_level(self, caplog):
+        import logging
+        loop = asyncio.new_event_loop()
+        loop.close()
+
+        async def _sample():
+            return None
+
+        custom = logging.getLogger("test_async_utils")
+        with caplog.at_level(logging.WARNING, logger="test_async_utils"):
+            result = safe_schedule_threadsafe(
+                _sample(), loop,
+                logger=custom,
+                log_message="custom-msg",
+                log_level=logging.WARNING,
+            )
+
+        assert result is None
+        assert any("custom-msg" in rec.message for rec in caplog.records)
+
+    def test_non_coroutine_arg_does_not_crash(self):
+        """Defensive: even if the caller hands us something weird, don't blow up."""
+        loop = asyncio.new_event_loop()
+        loop.close()
+
+        # Pass a non-coroutine sentinel
+        result = safe_schedule_threadsafe("not-a-coroutine", loop)  # type: ignore[arg-type]
+        assert result is None
diff --git a/tests/tools/test_mcp_probe.py b/tests/tools/test_mcp_probe.py
index 46459e44c87..89d4d1478d1 100644
--- a/tests/tools/test_mcp_probe.py
+++ b/tests/tools/test_mcp_probe.py
@@ -69,7 +69,8 @@ class TestProbeMcpServerTools:
              patch("tools.mcp_tool._stop_mcp_loop"):
 
             # Simulate running the async probe
-            def run_coro(coro, timeout=120):
+            def run_coro(coro_or_factory, timeout=120):
+                coro = coro_or_factory() if callable(coro_or_factory) else coro_or_factory
                 loop = asyncio.new_event_loop()
                 try:
                     return loop.run_until_complete(coro)
@@ -110,7 +111,8 @@ class TestProbeMcpServerTools:
              patch("tools.mcp_tool._run_on_mcp_loop") as mock_run, \
              patch("tools.mcp_tool._stop_mcp_loop"):
 
-            def run_coro(coro, timeout=120):
+            def run_coro(coro_or_factory, timeout=120):
+                coro = coro_or_factory() if callable(coro_or_factory) else coro_or_factory
                 loop = asyncio.new_event_loop()
                 try:
                     return loop.run_until_complete(coro)
@@ -144,7 +146,8 @@ class TestProbeMcpServerTools:
              patch("tools.mcp_tool._run_on_mcp_loop") as mock_run, \
              patch("tools.mcp_tool._stop_mcp_loop"):
 
-            def run_coro(coro, timeout=120):
+            def run_coro(coro_or_factory, timeout=120):
+                coro = coro_or_factory() if callable(coro_or_factory) else coro_or_factory
                 loop = asyncio.new_event_loop()
                 try:
                     return loop.run_until_complete(coro)
@@ -198,7 +201,8 @@ class TestProbeMcpServerTools:
              patch("tools.mcp_tool._run_on_mcp_loop") as mock_run, \
              patch("tools.mcp_tool._stop_mcp_loop"):
 
-            def run_coro(coro, timeout=120):
+            def run_coro(coro_or_factory, timeout=120):
+                coro = coro_or_factory() if callable(coro_or_factory) else coro_or_factory
                 loop = asyncio.new_event_loop()
                 try:
                     return loop.run_until_complete(coro)
diff --git a/tests/tools/test_mcp_structured_content.py b/tests/tools/test_mcp_structured_content.py
index 2870ce1e860..f4cda00f9f0 100644
--- a/tests/tools/test_mcp_structured_content.py
+++ b/tests/tools/test_mcp_structured_content.py
@@ -31,7 +31,8 @@ class _FakeCallToolResult:
         self.structuredContent = structuredContent
 
 
-def _fake_run_on_mcp_loop(coro, timeout=30):
+def _fake_run_on_mcp_loop(coro_or_factory, timeout=30):
+    coro = coro_or_factory() if callable(coro_or_factory) else coro_or_factory
     """Run an MCP coroutine directly in a fresh event loop."""
     loop = asyncio.new_event_loop()
     try:
diff --git a/tests/tools/test_mcp_tool.py b/tests/tools/test_mcp_tool.py
index 5558a0df48c..7f6c3f6704c 100644
--- a/tests/tools/test_mcp_tool.py
+++ b/tests/tools/test_mcp_tool.py
@@ -397,6 +397,77 @@ class TestCheckFunction:
             _servers.pop("test_server", None)
 
 
+# ---------------------------------------------------------------------------
+# MCP loop runner
+# ---------------------------------------------------------------------------
+
+class TestRunOnMcpLoop:
+    def test_scheduler_failure_closes_factory_coroutine(self):
+        """If run_coroutine_threadsafe raises, the factory's coroutine is closed."""
+        import gc
+        import warnings
+        import tools.mcp_tool as mcp
+
+        created = {"coro": None}
+
+        async def _sample():
+            return "ok"
+
+        def factory():
+            created["coro"] = _sample()
+            return created["coro"]
+
+        fake_loop = MagicMock()
+        fake_loop.is_running.return_value = True
+
+        with patch.object(mcp, "_mcp_loop", fake_loop):
+            with warnings.catch_warnings(record=True) as caught:
+                warnings.simplefilter("always")
+                with patch(
+                    "agent.async_utils.asyncio.run_coroutine_threadsafe",
+                    side_effect=RuntimeError("scheduler down"),
+                ):
+                    with pytest.raises(RuntimeError):
+                        mcp._run_on_mcp_loop(factory)
+                gc.collect()
+
+        assert created["coro"] is not None
+        assert created["coro"].cr_frame is None
+        runtime_warnings = [
+            w for w in caught
+            if issubclass(w.category, RuntimeWarning)
+            and "was never awaited" in str(w.message)
+            and "_sample" in str(w.message)
+        ]
+        assert runtime_warnings == []
+
+    def test_dead_loop_closes_passed_coroutine(self):
+        """If loop is None, a passed coroutine (not factory) is closed."""
+        import gc
+        import warnings
+        import tools.mcp_tool as mcp
+
+        async def _sample():
+            return "ok"
+
+        coro = _sample()
+        with patch.object(mcp, "_mcp_loop", None):
+            with warnings.catch_warnings(record=True) as caught:
+                warnings.simplefilter("always")
+                with pytest.raises(RuntimeError, match="not running"):
+                    mcp._run_on_mcp_loop(coro)
+                gc.collect()
+
+        assert coro.cr_frame is None
+        runtime_warnings = [
+            w for w in caught
+            if issubclass(w.category, RuntimeWarning)
+            and "was never awaited" in str(w.message)
+            and "_sample" in str(w.message)
+        ]
+        assert runtime_warnings == []
+
+
 # ---------------------------------------------------------------------------
 # Tool handler
 # ---------------------------------------------------------------------------
@@ -406,7 +477,8 @@ class TestToolHandler:
 
     def _patch_mcp_loop(self, coro_side_effect=None):
         """Return a patch for _run_on_mcp_loop that runs the coroutine directly."""
-        def fake_run(coro, timeout=30):
+        def fake_run(coro_or_factory, timeout=30):
+            coro = coro_or_factory() if callable(coro_or_factory) else coro_or_factory
             return asyncio.run(coro)
         if coro_side_effect:
             return patch("tools.mcp_tool._run_on_mcp_loop", side_effect=coro_side_effect)
@@ -485,7 +557,8 @@ class TestToolHandler:
 
         try:
             handler = _make_tool_handler("test_srv", "greet", 120)
-            def _interrupting_run(coro, timeout=30):
+            def _interrupting_run(coro_or_factory, timeout=30):
+                coro = coro_or_factory() if callable(coro_or_factory) else coro_or_factory
                 coro.close()
                 raise InterruptedError("User sent a new message")
             with patch(
@@ -1792,7 +1865,8 @@ class TestUtilityHandlers:
 
     def _patch_mcp_loop(self):
         """Return a patch for _run_on_mcp_loop that runs the coroutine directly."""
-        def fake_run(coro, timeout=30):
+        def fake_run(coro_or_factory, timeout=30):
+            coro = coro_or_factory() if callable(coro_or_factory) else coro_or_factory
             return asyncio.run(coro)
         return patch("tools.mcp_tool._run_on_mcp_loop", side_effect=fake_run)
 
diff --git a/tools/browser_cdp_tool.py b/tools/browser_cdp_tool.py
index 8e829556a57..f10a1541923 100644
--- a/tools/browser_cdp_tool.py
+++ b/tools/browser_cdp_tool.py
@@ -274,7 +274,13 @@ def _browser_cdp_via_supervisor(
         )
 
     try:
-        fut = _asyncio.run_coroutine_threadsafe(_do_cdp(), loop)
+        from agent.async_utils import safe_schedule_threadsafe
+        fut = safe_schedule_threadsafe(_do_cdp(), loop)
+        if fut is None:
+            return tool_error(
+                "CDP call via supervisor failed: loop unavailable",
+                cdp_docs=CDP_DOCS_URL,
+            )
         result_msg = fut.result(timeout=timeout + 2)
     except Exception as exc:
         return tool_error(
diff --git a/tools/browser_supervisor.py b/tools/browser_supervisor.py
index af8d40ee185..73dd3e51bb5 100644
--- a/tools/browser_supervisor.py
+++ b/tools/browser_supervisor.py
@@ -368,11 +368,13 @@ class CDPSupervisor:
                         pass
 
             try:
-                fut = asyncio.run_coroutine_threadsafe(_close_ws(), loop)
-                try:
-                    fut.result(timeout=2.0)
-                except Exception:
-                    pass
+                from agent.async_utils import safe_schedule_threadsafe
+                fut = safe_schedule_threadsafe(_close_ws(), loop)
+                if fut is not None:
+                    try:
+                        fut.result(timeout=2.0)
+                    except Exception:
+                        pass
             except RuntimeError:
                 pass  # loop already shutting down
         if self._thread is not None:
@@ -451,7 +453,10 @@ class CDPSupervisor:
             )
 
         try:
-            fut = asyncio.run_coroutine_threadsafe(_do_respond(), loop)
+            from agent.async_utils import safe_schedule_threadsafe
+            fut = safe_schedule_threadsafe(_do_respond(), loop)
+            if fut is None:
+                return {"ok": False, "error": "Browser supervisor loop unavailable"}
             fut.result(timeout=timeout)
         except Exception as e:
             return {"ok": False, "error": f"{type(e).__name__}: {e}"}
@@ -507,7 +512,10 @@ class CDPSupervisor:
             )
 
         try:
-            fut = asyncio.run_coroutine_threadsafe(_do_eval(), loop)
+            from agent.async_utils import safe_schedule_threadsafe
+            fut = safe_schedule_threadsafe(_do_eval(), loop)
+            if fut is None:
+                return {"ok": False, "error": "Browser supervisor loop unavailable"}
             response = fut.result(timeout=timeout + 1)
         except Exception as exc:
             return {"ok": False, "error": f"{type(exc).__name__}: {exc}"}
diff --git a/tools/computer_use/cua_backend.py b/tools/computer_use/cua_backend.py
index df1162c5d79..96aab60f8c7 100644
--- a/tools/computer_use/cua_backend.py
+++ b/tools/computer_use/cua_backend.py
@@ -183,9 +183,14 @@ class _AsyncBridge:
             raise RuntimeError("cua-driver asyncio bridge failed to start")
 
     def run(self, coro, timeout: Optional[float] = 30.0) -> Any:
+        from agent.async_utils import safe_schedule_threadsafe
         if not self._loop or not self._thread or not self._thread.is_alive():
+            if asyncio.iscoroutine(coro):
+                coro.close()
+            raise RuntimeError("cua-driver bridge not started")
+        fut = safe_schedule_threadsafe(coro, self._loop)
+        if fut is None:
             raise RuntimeError("cua-driver bridge not started")
-        fut: Future = asyncio.run_coroutine_threadsafe(coro, self._loop)
         return fut.result(timeout=timeout)
 
     def stop(self) -> None:
diff --git a/tools/environments/modal.py b/tools/environments/modal.py
index 1a230d85603..3137b322113 100644
--- a/tools/environments/modal.py
+++ b/tools/environments/modal.py
@@ -144,9 +144,14 @@ class _AsyncWorker:
         self._loop.run_forever()
 
     def run_coroutine(self, coro, timeout=600):
+        from agent.async_utils import safe_schedule_threadsafe
         if self._loop is None or self._loop.is_closed():
+            if asyncio.iscoroutine(coro):
+                coro.close()
+            raise RuntimeError("AsyncWorker loop is not running")
+        future = safe_schedule_threadsafe(coro, self._loop)
+        if future is None:
             raise RuntimeError("AsyncWorker loop is not running")
-        future = asyncio.run_coroutine_threadsafe(coro, self._loop)
         return future.result(timeout=timeout)
 
     def stop(self):
diff --git a/tools/mcp_tool.py b/tools/mcp_tool.py
index c2668395e5d..ba104cc4273 100644
--- a/tools/mcp_tool.py
+++ b/tools/mcp_tool.py
@@ -1781,7 +1781,7 @@ def _handle_auth_error_and_retry(
         return await manager.handle_401(server_name, None)
 
     try:
-        recovered = _run_on_mcp_loop(_recover(), timeout=10)
+        recovered = _run_on_mcp_loop(_recover, timeout=10)
     except Exception as rec_exc:
         logger.warning(
             "MCP OAuth '%s': recovery attempt failed: %s",
@@ -2054,19 +2054,35 @@ def _ensure_mcp_loop():
         _mcp_thread.start()
 
 
-def _run_on_mcp_loop(coro, timeout: float = 30):
+def _run_on_mcp_loop(coro_or_factory, timeout: float = 30):
     """Schedule a coroutine on the MCP event loop and block until done.
 
+    Accepts either a coroutine object or a zero-arg callable that returns one.
+    Callers can pass a factory to avoid constructing coroutine objects when
+    the MCP loop is unavailable (which would otherwise leak the coroutine
+    frame and emit ``"coroutine was never awaited"`` warnings).
+
     Poll in short intervals so the calling agent thread can honor user
     interrupts while the MCP work is still running on the background loop.
     """
     from tools.interrupt import is_interrupted
+    from agent.async_utils import safe_schedule_threadsafe
 
     with _lock:
         loop = _mcp_loop
     if loop is None or not loop.is_running():
+        if asyncio.iscoroutine(coro_or_factory):
+            coro_or_factory.close()
         raise RuntimeError("MCP event loop is not running")
-    future = asyncio.run_coroutine_threadsafe(coro, loop)
+
+    coro = coro_or_factory() if callable(coro_or_factory) else coro_or_factory
+    future = safe_schedule_threadsafe(
+        coro, loop,
+        logger=logger,
+        log_message="MCP scheduling failed",
+    )
+    if future is None:
+        raise RuntimeError("MCP event loop unavailable (failed to schedule)")
     start_time = time.monotonic()
     deadline = None if timeout is None else start_time + timeout
 
@@ -2263,7 +2279,7 @@ def _make_tool_handler(server_name: str, tool_name: str, tool_timeout: float):
             return json.dumps({"result": text_result}, ensure_ascii=False)
 
         def _call_once():
-            return _run_on_mcp_loop(_call(), timeout=tool_timeout)
+            return _run_on_mcp_loop(_call, timeout=tool_timeout)
 
         try:
             result = _call_once()
@@ -2343,7 +2359,7 @@ def _make_list_resources_handler(server_name: str, tool_timeout: float):
             return json.dumps({"resources": resources}, ensure_ascii=False)
 
         def _call_once():
-            return _run_on_mcp_loop(_call(), timeout=tool_timeout)
+            return _run_on_mcp_loop(_call, timeout=tool_timeout)
 
         try:
             return _call_once()
@@ -2403,7 +2419,7 @@ def _make_read_resource_handler(server_name: str, tool_timeout: float):
             return json.dumps({"result": "\n".join(parts) if parts else ""}, ensure_ascii=False)
 
         def _call_once():
-            return _run_on_mcp_loop(_call(), timeout=tool_timeout)
+            return _run_on_mcp_loop(_call, timeout=tool_timeout)
 
         try:
             return _call_once()
@@ -2466,7 +2482,7 @@ def _make_list_prompts_handler(server_name: str, tool_timeout: float):
             return json.dumps({"prompts": prompts}, ensure_ascii=False)
 
         def _call_once():
-            return _run_on_mcp_loop(_call(), timeout=tool_timeout)
+            return _run_on_mcp_loop(_call, timeout=tool_timeout)
 
         try:
             return _call_once()
@@ -2537,7 +2553,7 @@ def _make_get_prompt_handler(server_name: str, tool_timeout: float):
             return json.dumps(resp, ensure_ascii=False)
 
         def _call_once():
-            return _run_on_mcp_loop(_call(), timeout=tool_timeout)
+            return _run_on_mcp_loop(_call, timeout=tool_timeout)
 
         try:
             return _call_once()
@@ -3121,7 +3137,7 @@ def register_mcp_servers(servers: Dict[str, dict]) -> List[str]:
     if _was_interrupted:
         _set_interrupt(False)
     try:
-        _run_on_mcp_loop(_discover_all(), timeout=120)
+        _run_on_mcp_loop(_discover_all, timeout=120)
     finally:
         if _was_interrupted:
             _set_interrupt(True)
@@ -3289,7 +3305,7 @@ def probe_mcp_server_tools() -> Dict[str, List[tuple]]:
         )
 
     try:
-        _run_on_mcp_loop(_probe_all(), timeout=120)
+        _run_on_mcp_loop(_probe_all, timeout=120)
     except Exception as exc:
         logger.debug("MCP probe failed: %s", exc)
     finally:
@@ -3329,11 +3345,17 @@ def shutdown_mcp_servers():
     with _lock:
         loop = _mcp_loop
     if loop is not None and loop.is_running():
-        try:
-            future = asyncio.run_coroutine_threadsafe(_shutdown(), loop)
-            future.result(timeout=15)
-        except Exception as exc:
-            logger.debug("Error during MCP shutdown: %s", exc)
+        from agent.async_utils import safe_schedule_threadsafe
+        future = safe_schedule_threadsafe(
+            _shutdown(), loop,
+            logger=logger,
+            log_message="MCP shutdown: failed to schedule",
+        )
+        if future is not None:
+            try:
+                future.result(timeout=15)
+            except Exception as exc:
+                logger.debug("Error during MCP shutdown: %s", exc)
 
     _stop_mcp_loop()
 
diff --git a/tools/slash_confirm.py b/tools/slash_confirm.py
index 81c15263527..21db18fe319 100644
--- a/tools/slash_confirm.py
+++ b/tools/slash_confirm.py
@@ -153,9 +153,14 @@ def resolve_sync_compat(
     Prefer the async ``resolve()`` from an async context.
     """
     try:
-        fut = asyncio.run_coroutine_threadsafe(
+        from agent.async_utils import safe_schedule_threadsafe
+        fut = safe_schedule_threadsafe(
             resolve(session_key, confirm_id, choice), loop,
+            logger=logger,
+            log_message="resolve_sync_compat scheduling failed",
         )
+        if fut is None:
+            return None
         return fut.result(timeout=30)
     except Exception as exc:
         logger.error("resolve_sync_compat failed: %s", exc)
diff --git a/tui_gateway/ws.py b/tui_gateway/ws.py
index 1661811dbd6..a5879ef3a1c 100644
--- a/tui_gateway/ws.py
+++ b/tui_gateway/ws.py
@@ -83,7 +83,11 @@ class WSTransport:
             return True
 
         try:
-            fut = asyncio.run_coroutine_threadsafe(self._safe_send(line), self._loop)
+            from agent.async_utils import safe_schedule_threadsafe
+            fut = safe_schedule_threadsafe(self._safe_send(line), self._loop)
+            if fut is None:
+                self._closed = True
+                return False
             fut.result(timeout=_WS_WRITE_TIMEOUT_S)
             return not self._closed
         except Exception as exc: