diff --git a/python/dify_plugin/entities/model/llm.py b/python/dify_plugin/entities/model/llm.py
index ba301720..25f09c04 100644
--- a/python/dify_plugin/entities/model/llm.py
+++ b/python/dify_plugin/entities/model/llm.py
@@ -2,7 +2,7 @@ from decimal import Decimal
 from enum import Enum
 from typing import Optional
 
-from pydantic import BaseModel, ConfigDict
+from pydantic import BaseModel, ConfigDict, Field
 
 from dify_plugin.entities.model import BaseModelConfig, ModelType, ModelUsage, PriceInfo
 from dify_plugin.entities.model.message import (
@@ -139,6 +139,6 @@ class LLMModelConfig(BaseModelConfig):
 
     model_type: ModelType = ModelType.LLM
     mode: str
-    completion_params: dict | None = None
+    completion_params: dict = Field(default_factory=dict)
 
     model_config = ConfigDict(protected_namespaces=())
diff --git a/python/dify_plugin/invocations/model/llm.py b/python/dify_plugin/invocations/model/llm.py
index a8570435..9186400b 100644
--- a/python/dify_plugin/invocations/model/llm.py
+++ b/python/dify_plugin/invocations/model/llm.py
@@ -34,6 +34,16 @@ class LLMInvocation(BackwardsInvocation[LLMResultChunk]):
         stream: Literal[False] = False,
     ) -> LLMResult: ...
 
+    @overload
+    def invoke(
+        self,
+        model_config: LLMModelConfig,
+        prompt_messages: list[PromptMessage],
+        tools: list[PromptMessageTool] | None = None,
+        stop: list[str] | None = None,
+        stream: bool = True,
+    ) -> Generator[LLMResultChunk, None, None] | LLMResult: ...
+
     def invoke(
         self,
         model_config: LLMModelConfig,
diff --git a/python/dify_plugin/invocations/model/text_embedding.py b/python/dify_plugin/invocations/model/text_embedding.py
index 74ee775d..483f4b13 100644
--- a/python/dify_plugin/invocations/model/text_embedding.py
+++ b/python/dify_plugin/invocations/model/text_embedding.py
@@ -1,10 +1,10 @@
 from dify_plugin.core.entities.invocation import InvokeType
 from dify_plugin.core.runtime import BackwardsInvocation
-from dify_plugin.entities.model.text_embedding import TextEmbeddingResult
+from dify_plugin.entities.model.text_embedding import TextEmbeddingResult, TextEmbeddingModelConfig
 
 
 class TextEmbeddingInvocation(BackwardsInvocation[TextEmbeddingResult]):
-    def invoke(self, model_config: TextEmbeddingResult, texts: list[str]) -> TextEmbeddingResult:
+    def invoke(self, model_config: TextEmbeddingModelConfig, texts: list[str]) -> TextEmbeddingResult:
         """
         Invoke text embedding
         """