From 58600945d36b7bce111ca04e57d84eb8d36d44ee Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Wed, 4 Nov 2026 15:59:27 -0800
Subject: [PATCH] fix(least-busy): keep realtime sessions out of in-flight
 counts

---
 litellm/router_strategy/least_busy.py         |  4 +++-
 tests/unit/router_strategy/test_least_busy.py | 14 +++++++++++++-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/litellm/router_strategy/least_busy.py b/litellm/router_strategy/least_busy.py
index fbab70da286..22159079f98 100644
--- a/litellm/router_strategy/least_busy.py
+++ b/litellm/router_strategy/least_busy.py
@@ -17,6 +17,7 @@ from litellm.caching.in_memory_cache import InMemoryCache
 from litellm.caching.redis_cache import log_redis_failure
 from litellm.integrations.custom_logger import CustomLogger
 from litellm.litellm_core_utils.batch_utils import is_batch_retrieve_call_type
+from litellm.types.utils import CallTypes
 
 IN_FLIGHT_COUNT_TTL_SECONDS: Final = 60 * 60
 SELECTION_RESERVATION_TTL_SECONDS: Final = 30.0
@@ -97,7 +98,8 @@ def _routed_deployment_id(metadata: _Metadata | None) -> str | int | None:
 
 
 def _deployment_ref(kwargs: Mapping[str, object]) -> tuple[str, str] | None:
-    if is_batch_retrieve_call_type(kwargs.get("call_type")):
+    call_type: Final = kwargs.get("call_type")
+    if is_batch_retrieve_call_type(call_type) or call_type == CallTypes.arealtime.value:
         return None
     try:
         call: Final = _CALL_KWARGS.validate_python(kwargs)
diff --git a/tests/unit/router_strategy/test_least_busy.py b/tests/unit/router_strategy/test_least_busy.py
index 5b13d21af53..f156a5ee405 100644
--- a/tests/unit/router_strategy/test_least_busy.py
+++ b/tests/unit/router_strategy/test_least_busy.py
@@ -30,7 +30,7 @@ from litellm.router_strategy.least_busy import (
     picks_reserve,
     release_unstarted_picks,
 )
-from litellm.types.utils import ModelResponse
+from litellm.types.utils import CallTypes, ModelResponse
 
 GROUP: Final = "least-busy-group"
 DEPLOYMENT_A: Final[dict[str, object]] = {"model_info": {"id": "dep-a"}}
@@ -166,6 +166,18 @@ def test_a_request_routed_through_litellm_metadata_counts_while_in_flight() -> N
     assert calling_worker.get_available_deployments(GROUP, HEALTHY) is DEPLOYMENT_A
 
 
+def test_a_closed_realtime_session_leaves_its_deployment_idle() -> None:
+    shared: Final = SharedRedisCounters()
+    worker: Final = _worker(shared)
+    session_event: Final = {**_routed_through_litellm_metadata("dep-a"), "call_type": CallTypes.arealtime.value}
+
+    for _ in range(5):
+        worker.log_pre_api_call(model="m", messages=[], kwargs=session_event)
+    worker.log_success_event(session_event, None, None, None)
+
+    assert worker.get_available_deployments(GROUP, HEALTHY) is DEPLOYMENT_A
+
+
 def test_the_handler_never_pushes_a_counters_ttl_forward() -> None:
     """A worker that dies mid-request leaves a +1 nobody will ever decrement. Redis expires that
     stuck count an hour after the key was created, which only works while nothing writes the TTL