diff --git a/api/services/model_load_balancing_service.py b/api/services/model_load_balancing_service.py
index bc0bfd215cf..3cce83a975b 100644
--- a/api/services/model_load_balancing_service.py
+++ b/api/services/model_load_balancing_service.py
@@ -1,6 +1,6 @@
 import json
 import logging
-from typing import Any, Union
+from typing import Any, TypedDict, Union
 
 from graphon.model_runtime.entities.model_entities import ModelType
 from graphon.model_runtime.entities.provider_entities import (
@@ -25,6 +25,23 @@ from models.provider import LoadBalancingModelConfig, ProviderCredential, Provid
 logger = logging.getLogger(__name__)
 
 
+class LoadBalancingConfigDetailDict(TypedDict):
+    id: str
+    name: str
+    credentials: dict[str, Any]
+    enabled: bool
+
+
+class LoadBalancingConfigSummaryDict(TypedDict):
+    id: str
+    name: str
+    credentials: dict[str, Any]
+    credential_id: str | None
+    enabled: bool
+    in_cooldown: bool
+    ttl: int
+
+
 class ModelLoadBalancingService:
     @staticmethod
     def _get_provider_manager(tenant_id: str) -> ProviderManager:
@@ -74,7 +91,7 @@ class ModelLoadBalancingService:
 
     def get_load_balancing_configs(
         self, tenant_id: str, provider: str, model: str, model_type: str, config_from: str = ""
-    ) -> tuple[bool, list[dict]]:
+    ) -> tuple[bool, list[LoadBalancingConfigSummaryDict]]:
         """
         Get load balancing configurations.
         :param tenant_id: workspace id
@@ -156,7 +173,7 @@ class ModelLoadBalancingService:
         decoding_rsa_key, decoding_cipher_rsa = encrypter.get_decrypt_decoding(tenant_id)
 
         # fetch status and ttl for each config
-        datas = []
+        datas: list[LoadBalancingConfigSummaryDict] = []
         for load_balancing_config in load_balancing_configs:
             in_cooldown, ttl = LBModelManager.get_config_in_cooldown_and_ttl(
                 tenant_id=tenant_id,
@@ -214,7 +231,7 @@ class ModelLoadBalancingService:
 
     def get_load_balancing_config(
         self, tenant_id: str, provider: str, model: str, model_type: str, config_id: str
-    ) -> dict | None:
+    ) -> LoadBalancingConfigDetailDict | None:
         """
         Get load balancing configuration.
         :param tenant_id: workspace id
@@ -267,12 +284,13 @@ class ModelLoadBalancingService:
             credentials=credentials, credential_form_schemas=credential_schemas.credential_form_schemas
         )
 
-        return {
+        result: LoadBalancingConfigDetailDict = {
             "id": load_balancing_model_config.id,
             "name": load_balancing_model_config.name,
             "credentials": credentials,
             "enabled": load_balancing_model_config.enabled,
         }
+        return result
 
     def _init_inherit_config(
         self, tenant_id: str, provider: str, model: str, model_type: ModelType
diff --git a/api/services/workflow_service.py b/api/services/workflow_service.py
index 662e0410f96..eeb795e5a85 100644
--- a/api/services/workflow_service.py
+++ b/api/services/workflow_service.py
@@ -635,7 +635,7 @@ class WorkflowService:
             # If we can't determine the status, assume load balancing is not enabled
             return False
 
-    def _get_load_balancing_configs(self, tenant_id: str, provider: str, model_name: str) -> list[dict]:
+    def _get_load_balancing_configs(self, tenant_id: str, provider: str, model_name: str) -> list[dict[str, Any]]:
         """
         Get all load balancing configurations for a model.
 
@@ -659,7 +659,7 @@ class WorkflowService:
             _, custom_configs = model_load_balancing_service.get_load_balancing_configs(
                 tenant_id=tenant_id, provider=provider, model=model_name, model_type="llm", config_from="custom-model"
             )
-            all_configs = configs + custom_configs
+            all_configs = cast(list[dict[str, Any]], configs) + cast(list[dict[str, Any]], custom_configs)
 
             return [config for config in all_configs if config.get("credential_id")]