fix(model_info): map supports_parallel_function_calling into ModelInfo

The registry key was never copied into ModelInfo, so /v1/model/info reported
null for every model, /model_group/info reported false for every group, and
litellm.supports_parallel_function_calling() returned False for provider-prefixed
entries that declare true. Copy it like every other capability flag and pin the
three surfaces with regression tests.

Resolves LIT-6340

litellm/utils.py

@@ -5866,6 +5866,7 @@ def _get_model_info_helper(
                 supports_response_schema=_model_info.get("supports_response_schema", None),
                 supports_vision=_model_info.get("supports_vision", None),
                 supports_function_calling=_model_info.get("supports_function_calling", None),
+                supports_parallel_function_calling=_model_info.get("supports_parallel_function_calling", None),
                 supports_tool_choice=_model_info.get("supports_tool_choice", None),
                 supports_assistant_prefill=_model_info.get("supports_assistant_prefill", None),
                 supports_prompt_caching=_model_info.get("supports_prompt_caching", None),

tests/test_litellm/proxy/proxy_server/test_routes_model_info.py

@@ -128,6 +128,20 @@ def test_v1_model_info_no_model_list_error(client, auth_as, null_router, path):
     assert "LLM Model List not loaded" in response.text
 
 
+
+def test_get_proxy_model_info_surfaces_supports_parallel_function_calling(local_model_cost_map):
+    """``GET /v1/model/info`` enriches each deployment through ``_get_proxy_model_info``; a registry
+    entry declaring parallel function calling must land in ``model_info`` instead of null."""
+    enriched = proxy_server._get_proxy_model_info(
+        model={
+            "model_name": "glm-5.3-flash",
+            "litellm_params": {"model": "together_ai/zai-org/GLM-5.3-Flash"},
+            "model_info": {"id": "glm-deployment", "db_model": False},
+        }
+    )
+    assert enriched["model_info"]["supports_parallel_function_calling"] is True
+
+
 def test_v1_model_info_star_wildcard_filter_keeps_provider_expansion(monkeypatch):
     from litellm.proxy._types import SpecialModelNames, UserAPIKeyAuth
     from litellm.proxy.auth import model_checks

tests/test_litellm/test_router.py

@@ -9051,6 +9051,25 @@ def test_model_group_info_reasoning_efforts_ignore_a_deployment_off_the_map():
     assert result.supported_reasoning_efforts == ("none", "minimal", "low", "medium", "high", "max")
 
 
+
+def test_model_group_info_surfaces_supports_parallel_function_calling(local_model_cost_map):
+    """``/model_group/info`` folds each deployment's registry flags into the group; a deployment whose
+    registry entry declares parallel function calling must flip the group to True instead of False."""
+    router = litellm.Router(
+        model_list=[
+            {
+                "model_name": "glm-group",
+                "litellm_params": {"model": "together_ai/zai-org/GLM-5.3-Flash", "api_key": "fake-key"},
+            }
+        ]
+    )
+
+    result = router._set_model_group_info(model_group="glm-group", user_facing_model_group_name="glm-group")
+
+    assert result is not None
+    assert result.supports_parallel_function_calling is True
+
+
 def test_model_group_info_reasoning_efforts_empty_on_a_mapped_non_reasoning_deployment():
     """A group mixing a reasoning model with one the map knows is not a reasoning model shares no
     level, so it advertises none and the picker offers nothing rather than a level routing would

tests/test_litellm/test_utils.py

@@ -120,6 +120,21 @@ def test_get_model_info_surfaces_supports_adaptive_thinking(local_model_cost_map
     assert generalized["supports_adaptive_thinking"] is True
 
 
+
+def test_get_model_info_surfaces_supports_parallel_function_calling(local_model_cost_map):
+    """A registry entry's supports_parallel_function_calling must read back through get_model_info
+    and litellm.supports_parallel_function_calling. Regression: the key was never copied into
+    ModelInfo, so provider-prefixed entries read None / False even when the map said True, and an
+    explicit False was indistinguishable from unset."""
+    declared_true = litellm.get_model_info(model="together_ai/zai-org/GLM-5.3-Flash")
+    assert declared_true["supports_parallel_function_calling"] is True
+    assert litellm.supports_parallel_function_calling(model="together_ai/zai-org/GLM-5.3-Flash") is True
+
+    declared_false = litellm.get_model_info(model="o3-mini")
+    assert declared_false["supports_parallel_function_calling"] is False
+    assert litellm.supports_parallel_function_calling(model="o3-mini") is False
+
+
 def test_get_model_info_surfaces_supported_endpoints(local_model_cost_map):
     """supported_endpoints ships in the cost map and is declared on ModelInfoBase,
     but the constructor never copied it, so get_model_info always returned None.