diff --git a/src/toad/acp/agent_process.py b/src/toad/acp/agent_process.py
index e1ce7831a..b985f69b4 100644
--- a/src/toad/acp/agent_process.py
+++ b/src/toad/acp/agent_process.py
@@ -5,8 +5,8 @@
 import json
 import os
 from collections.abc import Callable
-from contextlib import ExitStack
 from contextvars import ContextVar
+from functools import partial
 from pathlib import Path
 from typing import Optional
 
@@ -70,8 +70,7 @@ async def start(self, agent, processes: tuple[AgentProcess, ...]=()):
         env = os.environ.copy()
         cwd = str(agent.project_root_path.resolve())
         selection = RouteSelection.capture(agent.controller.transcripts.access.launch_root.path)
-        with ExitStack() as acquisition:
-            acquisition.enter_context(selection.route.hold_client_route())
+        with selection.route.hold_client_route():
             if not agent.session.accepts_updates:
                 return self
             for connection in dict.fromkeys((self, *processes)):
@@ -95,6 +94,8 @@ async def start(self, agent, processes: tuple[AgentProcess, ...]=()):
 
     async def prompt(self, agent, content, metadata: dict[str, JsonValue], require: Callable[[], None]):
         """The agent-comms-acp child writes the prompt under Core's maintenance gate."""
+        access = agent.controller.transcripts.access
+        await access.preparation.run_thread(partial(access.require, self.route_selection))
         require()
         return await self.rpc.prompt(agent.session_id, content, **metadata)
 
diff --git a/src/toad/comms_root.py b/src/toad/comms_root.py
index 75198f65a..fdf00ee28 100644
--- a/src/toad/comms_root.py
+++ b/src/toad/comms_root.py
@@ -14,7 +14,6 @@
 import asyncio
 import threading
 from collections.abc import Callable, Mapping
-from contextlib import ExitStack
 from dataclasses import dataclass, field
 from functools import partial
 from pathlib import Path
@@ -372,8 +371,7 @@ def require(self, selected: RouteSelection) -> Observing:
     def open_selected(self, selected: RouteSelection) -> Observing:
         def attach() -> Observing:
             previous = self.observation
-            with ExitStack() as acquisition:
-                acquisition.enter_context(selected.route.hold_client_route())
+            with selected.route.hold_client_route():
                 service = Comms(selected.route)
                 if service.root.resolve() != selected.root or RouteSelection.capture() != selected:
                     raise RouteChangedError("Comms route changed while opening the service")