Reject RedisCluster clients with a clear error

README.md

@@ -145,6 +145,11 @@ Run multiple `TimersBroker` processes against the same Redis keys. The Lua
 claim script ensures each due timer is leased by exactly one worker at a
 time; failover is automatic via lease expiry.
 
+Supports single-primary Redis, including Sentinel-managed primary/replica
+setups. Redis Cluster is **not** supported: each topic's timeline and
+payload keys must live on the same node, and the broker raises a
+`TypeError` if constructed with a `RedisCluster` client.
+
 ```python
 broker = TimersBroker(
     Redis.from_url("redis://..."),

faststream_redis_timers/broker.py

@@ -18,6 +18,7 @@
 from faststream.response.publish_type import PublishType
 from faststream.specification.schema import BrokerSpec
 from faststream.specification.schema.extra import Tag, TagDict
+from redis.asyncio.cluster import RedisCluster
 
 from faststream_redis_timers.configs import ConnectionState, RedisClient, TimersBrokerConfig
 from faststream_redis_timers.message import TimerMessage
@@ -99,6 +100,13 @@ def __init__(  # noqa: PLR0913
         description: str | None = None,
         tags: Iterable[Tag | TagDict] = (),
     ) -> None:
+        if isinstance(client, RedisCluster):
+            msg = (
+                "TimersBroker does not support RedisCluster clients: the timeline and "
+                "payload keys for a topic must live on the same node. Use a single-primary "
+                "Redis (Sentinel-managed primary/replica setups are supported)."
+            )
+            raise TypeError(msg)
         fd_config = FastDependsConfig(use_fastdepends=apply_types)
         connection = ConnectionState(client)
         broker_config = TimersBrokerConfig(

tests/test_unit.py

@@ -6,6 +6,7 @@
 import faststream.asgi.factories.asyncapi.try_it_out
 import pytest
 from faststream.exceptions import IncorrectState
+from redis.asyncio.cluster import RedisCluster
 from redis.exceptions import NoScriptError
 
 from faststream_redis_timers import TestTimersBroker, TimersBroker
@@ -56,6 +57,12 @@ async def test_broker_config_connect_and_disconnect() -> None:
     await config.disconnect()
 
 
+def test_broker_rejects_redis_cluster_client() -> None:
+    fake_cluster = MagicMock(spec=RedisCluster)
+    with pytest.raises(TypeError, match="RedisCluster"):
+        TimersBroker(fake_cluster)
+
+
 # --- TimersBroker.ping ---