diff --git a/flowy/nodes_omost.py b/flowy/nodes_omost.py
index e29f716..66df388 100644
--- a/flowy/nodes_omost.py
+++ b/flowy/nodes_omost.py
@@ -18,6 +18,8 @@ from .lib_omost.greedy_encode import (
 CATEGORY = "Comflowy/Omost"
 from .utils import llm_request, logger
 from .types import LLM_MODELS, STRING
+from .api_key_manager import load_api_key  # Add this import
+
 CANVAS_SIZE = 90
 
 system_prompt = r"""You are a helpful AI assistant to compose images using the a json-based canvas system:
@@ -102,7 +104,6 @@ class OmostLLMNode:
             "required": {
                 "prompt": ("STRING", {"multiline": True}),
                 "llm_model": (LLM_MODELS,),
-                "api_key": STRING,
                 "seed": ("INT", {"default": 0, "min": 0, "max": 0xFFFFFFFFFFFFFFFF}),
             },
         }
@@ -117,12 +118,16 @@ class OmostLLMNode:
     FUNCTION = "run_llm"
     CATEGORY = CATEGORY
 
-    def run_llm(self, prompt: str, llm_model: str, seed: int, api_key: str) -> Tuple[list[OmostCanvasCondition]]:
+    def run_llm(self, prompt: str, llm_model: str, seed: int) -> Tuple[list[OmostCanvasCondition]]:
         """Run LLM to generate area conditioning."""
         if seed > 0xFFFFFFFF:
             seed = seed & 0xFFFFFFFF
             logger.warning("Seed is too large. Truncating to 32-bit: %d", seed)
 
+        api_key = load_api_key()
+        if not api_key:
+            raise ValueError("API Key is not set. Please use the 'Comflowy Set API Key' node to set a global API Key before using this node.")
+
         try:
             generated_text = llm_request(prompt=prompt, llm_model=llm_model, system_prompt=system_prompt, api_key=api_key, max_tokens=4000, timeout=10)
             # 如果生成的字符中包含了多余的字符，比如 "```json" 或者  "```"，则需要去掉改行
diff --git a/flowy/utils.py b/flowy/utils.py
index ac912ae..9db80dc 100644
--- a/flowy/utils.py
+++ b/flowy/utils.py
@@ -47,3 +47,26 @@ def llm_request(prompt, system_prompt, llm_model, api_key, max_tokens=3000, time
             raise Exception(f"Error: {ret.get('error')}")
     except Exception as e:
         raise Exception(f"Failed to get response from LLM model with {API_HOST}/api/open/v0/prompt, error: {str(e)}")
+
+def get_nested_value(obj, path, default=None):
+    """
+    Get a nested value from a dictionary using a dot-separated path.
+    
+    Args:
+        obj (dict): The dictionary to search in.
+        path (str): The dot-separated path to the desired value.
+        default: The value to return if the path is not found.
+    
+    Returns:
+        The value at the specified path, or the default value if not found.
+    """
+    keys = path.split('.')
+    for key in keys:
+        if isinstance(obj, dict):
+            obj = obj.get(key, default)
+        else:
+            return default
+    return obj
+
+# Make sure to export the functions
+__all__ = ['llm_request', 'get_nested_value']