diff --git a/docs/components/llms/config.mdx b/docs/components/llms/config.mdx
index 5c471cbb..626304dc 100644
--- a/docs/components/llms/config.mdx
+++ b/docs/components/llms/config.mdx
@@ -9,6 +9,16 @@ The config is defined as a Python dictionary with two main keys:
   - `provider`: The name of the llm (e.g., "openai", "groq")
   - `config`: A nested dictionary containing provider-specific settings
 
+### Config Values Precedence
+
+Config values are applied in the following order of precedence (from highest to lowest):
+
+1. Values explicitly set in the `config` dictionary
+2. Environment variables (e.g., `OPENAI_API_KEY`, `OPENAI_API_BASE`)
+3. Default values defined in the LLM implementation
+
+This means that values specified in the `config` dictionary will override corresponding environment variables, which in turn override default values.
+
 ## How to Use Config
 
 Here's a general example of how to use the config with mem0:
diff --git a/mem0/configs/llms/base.py b/mem0/configs/llms/base.py
index 94c8e278..f9d63485 100644
--- a/mem0/configs/llms/base.py
+++ b/mem0/configs/llms/base.py
@@ -22,9 +22,9 @@ class BaseLlmConfig(ABC):
         # Openrouter specific
         models: Optional[list[str]] = None,
         route: Optional[str] = "fallback",
-        openrouter_base_url: Optional[str] = "https://openrouter.ai/api/v1",
+        openrouter_base_url: Optional[str] = None,
         # Openai specific
-        openai_base_url: Optional[str] = "https://api.openai.com/v1",
+        openai_base_url: Optional[str] = None,
         site_url: Optional[str] = None,
         app_name: Optional[str] = None,
         # Ollama specific
diff --git a/mem0/llms/openai.py b/mem0/llms/openai.py
index 89bef986..c585162f 100644
--- a/mem0/llms/openai.py
+++ b/mem0/llms/openai.py
@@ -18,11 +18,11 @@ class OpenAILLM(LLMBase):
         if os.environ.get("OPENROUTER_API_KEY"):  # Use OpenRouter
             self.client = OpenAI(
                 api_key=os.environ.get("OPENROUTER_API_KEY"),
-                base_url=self.config.openrouter_base_url,
+                base_url=self.config.openrouter_base_url or os.getenv("OPENROUTER_API_BASE") or "https://openrouter.ai/api/v1",
             )
         else:
             api_key = self.config.api_key or os.getenv("OPENAI_API_KEY")
-            base_url = os.getenv("OPENAI_API_BASE") or self.config.openai_base_url
+            base_url = self.config.openai_base_url or os.getenv("OPENAI_API_BASE") or "https://api.openai.com/v1"
             self.client = OpenAI(api_key=api_key, base_url=base_url)
 
     def _parse_response(self, response, tools):
diff --git a/mem0/llms/openai_structured.py b/mem0/llms/openai_structured.py
index 4060afb8..1ccba28a 100644
--- a/mem0/llms/openai_structured.py
+++ b/mem0/llms/openai_structured.py
@@ -16,7 +16,7 @@ class OpenAIStructuredLLM(LLMBase):
             self.config.model = "gpt-4o-2024-08-06"
 
         api_key = self.config.api_key or os.getenv("OPENAI_API_KEY")
-        base_url = self.config.openai_base_url or os.getenv("OPENAI_API_BASE")
+        base_url = self.config.openai_base_url or os.getenv("OPENAI_API_BASE") or "https://api.openai.com/v1"
         self.client = OpenAI(api_key=api_key, base_url=base_url)
 
     def _parse_response(self, response, tools):
diff --git a/tests/llms/test_openai.py b/tests/llms/test_openai.py
index be2f6f95..9e62c6f2 100644
--- a/tests/llms/test_openai.py
+++ b/tests/llms/test_openai.py
@@ -1,5 +1,5 @@
 from unittest.mock import Mock, patch
-
+import os
 import pytest
 
 from mem0.configs.llms.base import BaseLlmConfig
@@ -14,6 +14,30 @@ def mock_openai_client():
         yield mock_client
 
 
+def test_openai_llm_base_url():
+    # case1: default config: with openai official base url
+    config = BaseLlmConfig(model="gpt-4o", temperature=0.7, max_tokens=100, top_p=1.0, api_key="api_key")
+    llm = OpenAILLM(config)
+    # Note: openai client will parse the raw base_url into a URL object, which will have a trailing slash
+    assert str(llm.client.base_url) == "https://api.openai.com/v1/"
+
+    # case2: with env variable OPENAI_API_BASE
+    provider_base_url = "https://api.provider.com/v1"
+    os.environ["OPENAI_API_BASE"] = provider_base_url
+    config = BaseLlmConfig(model="gpt-4o", temperature=0.7, max_tokens=100, top_p=1.0, api_key="api_key")
+    llm = OpenAILLM(config)
+    # Note: openai client will parse the raw base_url into a URL object, which will have a trailing slash
+    assert str(llm.client.base_url) == provider_base_url + "/"
+
+    # case3: with config.openai_base_url
+    config_base_url = "https://api.config.com/v1"
+    config = BaseLlmConfig(model="gpt-4o", temperature=0.7, max_tokens=100, top_p=1.0, api_key="api_key",
+                           openai_base_url=config_base_url)
+    llm = OpenAILLM(config)
+    # Note: openai client will parse the raw base_url into a URL object, which will have a trailing slash
+    assert str(llm.client.base_url) == config_base_url + "/"
+
+
 def test_generate_response_without_tools(mock_openai_client):
     config = BaseLlmConfig(model="gpt-4o", temperature=0.7, max_tokens=100, top_p=1.0)
     llm = OpenAILLM(config)