feat: Add lazy loading for get_llm_provider to reduce import time

- Add get_llm_provider to lazy import registry system
- Remove eager import from __init__.py
- Fix circular import by updating internal modules to import directly from source:
  - realtime_api/main.py
  - router_utils/pattern_match_deployments.py
- Add type stub for get_llm_provider in TYPE_CHECKING block
- Add tests for lazy loading of LLM provider logic functions

This reduces initial import time and memory usage by deferring the import
of get_llm_provider until it's actually accessed.

litellm/__init__.py

@@ -1057,7 +1057,7 @@ openai_image_generation_models = ["dall-e-2", "dall-e-3"]
 openai_video_generation_models = ["sora-2"]
 
 # timeout is lazy-loaded via __getattr__
-from litellm.litellm_core_utils.get_llm_provider_logic import get_llm_provider
+# get_llm_provider is lazy-loaded via __getattr__
 from litellm.litellm_core_utils.core_helpers import remove_index_from_tool_calls
 
 # Import KeyManagementSettings here (before utils import) because _key_management_settings
@@ -1507,6 +1507,7 @@ if TYPE_CHECKING:
     get_first_chars_messages: Callable[..., str]
     get_provider_fields: Callable[..., List]
     get_valid_models: Callable[..., list]
+    get_llm_provider: Callable[..., Tuple[str, str, Optional[str], Optional[str]]]
 
     # Response types - truly lazy loaded only (not in main.py or elsewhere)
     ModelResponseListIterator: Type[Any]

litellm/_lazy_imports.py

@@ -34,6 +34,7 @@ from ._lazy_imports_registry import (
     DOTPROMPT_NAMES,
     LLM_CONFIG_NAMES,
     TYPES_NAMES,
+    LLM_PROVIDER_LOGIC_NAMES,
     # Import maps
     _UTILS_IMPORT_MAP,
     _COST_CALCULATOR_IMPORT_MAP,
@@ -45,6 +46,7 @@ from ._lazy_imports_registry import (
     _DOTPROMPT_IMPORT_MAP,
     _TYPES_IMPORT_MAP,
     _LLM_CONFIGS_IMPORT_MAP,
+    _LLM_PROVIDER_LOGIC_IMPORT_MAP,
 )
 
 
@@ -181,6 +183,8 @@ def _get_lazy_import_registry() -> dict[str, Callable[[str], Any]]:
             _LAZY_IMPORT_REGISTRY[name] = _lazy_import_llm_configs
         for name in TYPES_NAMES:
             _LAZY_IMPORT_REGISTRY[name] = _lazy_import_types
+        for name in LLM_PROVIDER_LOGIC_NAMES:
+            _LAZY_IMPORT_REGISTRY[name] = _lazy_import_llm_provider_logic
     
     return _LAZY_IMPORT_REGISTRY
 
@@ -297,6 +301,11 @@ def _lazy_import_litellm_logging(name: str) -> Any:
     """Handler for litellm_logging module (Logging, modify_integration)"""
     return _generic_lazy_import(name, _LITELLM_LOGGING_IMPORT_MAP, "Litellm logging")
 
+
+def _lazy_import_llm_provider_logic(name: str) -> Any:
+    """Handler for LLM provider logic functions (get_llm_provider, etc.)"""
+    return _generic_lazy_import(name, _LLM_PROVIDER_LOGIC_IMPORT_MAP, "LLM provider logic")
+
 # ============================================================================
 # SPECIAL HANDLERS
 # ============================================================================

litellm/_lazy_imports_registry.py

@@ -287,6 +287,11 @@ TYPES_NAMES = (
     # is accessed during import time in secret_managers/main.py
 )
 
+# LLM provider logic names that support lazy loading via _lazy_import_llm_provider_logic
+LLM_PROVIDER_LOGIC_NAMES = (
+    "get_llm_provider",
+)
+
 # Import maps for registry pattern - reduces repetition
 _UTILS_IMPORT_MAP = {
     "exception_type": (".utils", "exception_type"),
@@ -386,6 +391,10 @@ _TYPES_IMPORT_MAP = {
     "LoggingCallbackManager": ("litellm.litellm_core_utils.logging_callback_manager", "LoggingCallbackManager"),
 }
 
+_LLM_PROVIDER_LOGIC_IMPORT_MAP = {
+    "get_llm_provider": ("litellm.litellm_core_utils.get_llm_provider_logic", "get_llm_provider"),
+}
+
 _LLM_CONFIGS_IMPORT_MAP = {
     "AmazonConverseConfig": (".llms.bedrock.chat.converse_transformation", "AmazonConverseConfig"),
     "OpenAILikeChatConfig": (".llms.openai_like.chat.handler", "OpenAILikeChatConfig"),
@@ -587,6 +596,7 @@ __all__ = [
     "DOTPROMPT_NAMES",
     "LLM_CONFIG_NAMES",
     "TYPES_NAMES",
+    "LLM_PROVIDER_LOGIC_NAMES",
     # Import maps
     "_UTILS_IMPORT_MAP",
     "_COST_CALCULATOR_IMPORT_MAP",
@@ -598,5 +608,6 @@ __all__ = [
     "_DOTPROMPT_IMPORT_MAP",
     "_TYPES_IMPORT_MAP",
     "_LLM_CONFIGS_IMPORT_MAP",
+    "_LLM_PROVIDER_LOGIC_IMPORT_MAP",
 ]
 

litellm/realtime_api/main.py

@@ -3,7 +3,7 @@
 from typing import Any, Optional, cast
 
 import litellm
-from litellm import get_llm_provider
+from litellm.litellm_core_utils.get_llm_provider_logic import get_llm_provider
 from litellm.constants import REALTIME_WEBSOCKET_MAX_MESSAGE_SIZE_BYTES
 from litellm.llms.base_llm.realtime.transformation import BaseRealtimeConfig
 from litellm.llms.custom_httpx.llm_http_handler import BaseLLMHTTPHandler

litellm/router_utils/pattern_match_deployments.py

@@ -7,7 +7,7 @@ import re
 from re import Match
 from typing import Dict, List, Optional, Tuple
 
-from litellm import get_llm_provider
+from litellm.litellm_core_utils.get_llm_provider_logic import get_llm_provider
 from litellm._logging import verbose_router_logger
 
 

tests/test_litellm/test_lazy_imports.py

@@ -33,6 +33,8 @@ from litellm._lazy_imports import (
     _lazy_import_llm_configs,
     TYPES_NAMES,
     _lazy_import_types,
+    LLM_PROVIDER_LOGIC_NAMES,
+    _lazy_import_llm_provider_logic,
 )
 
 
@@ -218,6 +220,9 @@ def test_unknown_attribute_raises_error():
     with pytest.raises(AttributeError):
         _lazy_import_types("unknown")
 
+    with pytest.raises(AttributeError):
+        _lazy_import_llm_provider_logic("unknown")
+
 
 def test_llm_config_lazy_imports():
     """Test that LLM config classes can be lazy imported."""
@@ -246,3 +251,16 @@ def test_types_lazy_imports():
 
         _verify_only_requested_name_imported(name, TYPES_NAMES)
 
+
+def test_llm_provider_logic_lazy_imports():
+    """Test that LLM provider logic functions can be lazy imported."""
+    for name in LLM_PROVIDER_LOGIC_NAMES:
+        _clear_names_from_globals(LLM_PROVIDER_LOGIC_NAMES)
+
+        func = _lazy_import_llm_provider_logic(name)
+        assert func is not None
+        assert callable(func)
+        assert name in litellm.__dict__
+
+        _verify_only_requested_name_imported(name, LLM_PROVIDER_LOGIC_NAMES)
+