diff --git a/coagent/cli/main.py b/coagent/cli/main.py
index af59b10..b518aa5 100644
--- a/coagent/cli/main.py
+++ b/coagent/cli/main.py
@@ -7,7 +7,6 @@
 
 from coagent.core import Address, RawMessage, set_stderr_logger
 from coagent.core.exceptions import BaseError
-from coagent.core.messages import Cancel
 from coagent.runtimes import NATSRuntime, HTTPRuntime
 
 
@@ -70,7 +69,7 @@ async def run(
                 async for chunk in runtime.channel.publish_multi(addr, msg):
                     print_msg(chunk, oneline, filter)
         except asyncio.CancelledError:
-            await runtime.channel.publish(addr, Cancel().encode(), probe=False)
+            await runtime.channel.cancel(addr)
         except BaseError as exc:
             print(f"Error: {exc}")
 
diff --git a/coagent/core/runtime.py b/coagent/core/runtime.py
index 5d6c27e..c5ddd59 100644
--- a/coagent/core/runtime.py
+++ b/coagent/core/runtime.py
@@ -5,7 +5,7 @@
 
 from .discovery import Discovery
 from .exceptions import BaseError
-from .messages import StopIteration, Error
+from .messages import Cancel, Error, StopIteration
 from .factory import Factory
 from .types import (
     AgentSpec,
@@ -101,6 +101,12 @@ async def publish_multi(
         finally:
             await sub.unsubscribe()
 
+    async def cancel(self, addr: Address) -> None:
+        """Cancel the agent with the given address."""
+
+        # A shortcut for sending a Cancel message to the agent.
+        await self.publish(addr, Cancel().encode(), probe=False)
+
 
 class QueueSubscriptionIterator:
     """A Queue-based async iterator that receives messages from a subscription and yields them."""
diff --git a/coagent/core/types.py b/coagent/core/types.py
index 8e6a2e1..97f46bf 100644
--- a/coagent/core/types.py
+++ b/coagent/core/types.py
@@ -268,6 +268,11 @@ async def subscribe(
     async def new_reply_topic(self) -> str:
         pass
 
+    @abc.abstractmethod
+    async def cancel(self, addr: Address) -> None:
+        """Cancel the agent with the given address."""
+        pass
+
 
 @dataclasses.dataclass
 class AgentSpec:
diff --git a/coagent/cos/runtime.py b/coagent/cos/runtime.py
index c79f812..5a21e50 100644
--- a/coagent/cos/runtime.py
+++ b/coagent/cos/runtime.py
@@ -14,7 +14,6 @@
     RawMessage,
     logger,
 )
-from coagent.core.messages import Cancel
 from coagent.core.exceptions import BaseError
 from coagent.core.types import Runtime
 from coagent.core.util import clear_queue
@@ -149,7 +148,7 @@ async def publish(self, request: Request):
             # Disconnected from the client.
 
             # Cancel the ongoing operation.
-            await self._runtime.channel.publish(addr, Cancel().encode())
+            await self._runtime.channel.cancel(addr)
 
         if resp is None:
             return Response(status_code=204)
@@ -178,7 +177,7 @@ async def event_stream() -> AsyncIterator[str]:
                 # Disconnected from the client.
 
                 # Cancel the ongoing operation.
-                await self._runtime.channel.publish(addr, Cancel().encode())
+                await self._runtime.channel.cancel(addr)
 
         return EventSourceResponse(event_stream())
 
diff --git a/tests/core/test_agent.py b/tests/core/test_agent.py
index 0e30cbd..1c091f3 100644
--- a/tests/core/test_agent.py
+++ b/tests/core/test_agent.py
@@ -6,7 +6,7 @@
 from coagent.core.types import Address, Agent, Channel, RawMessage
 from coagent.core.agent import BaseAgent, Context, handler
 from coagent.core.exceptions import BaseError
-from coagent.core.messages import Cancel, Message
+from coagent.core.messages import Message
 
 
 class Query(Message):
@@ -89,7 +89,7 @@ async def test_cancel(self, local_channel, run_agent_in_task, yield_control):
 
         async def cancel():
             await asyncio.sleep(0.01)
-            await local_channel.publish(addr, Cancel().encode())
+            await local_channel.cancel(addr)
 
         _ = asyncio.create_task(cancel())
         await yield_control()
@@ -130,7 +130,7 @@ async def test_cancel(self, local_channel, run_agent_in_task, yield_control):
 
         async def cancel():
             await asyncio.sleep(0.01)
-            await local_channel.publish(addr, Cancel().encode())
+            await local_channel.cancel(addr)
 
         _ = asyncio.create_task(cancel())
         await yield_control()