diff --git a/mem0/llms/anthropic.py b/mem0/llms/anthropic.py
index f5e8dbce4..179f1b4ff 100644
--- a/mem0/llms/anthropic.py
+++ b/mem0/llms/anthropic.py
@@ -38,7 +38,11 @@ class AnthropicLLM(LLMBase):
             self.config.model = "claude-sonnet-4-6"
 
         api_key = self.config.api_key or os.getenv("ANTHROPIC_API_KEY")
-        self.client = anthropic.Anthropic(api_key=api_key)
+        base_url = self.config.anthropic_base_url or os.getenv("ANTHROPIC_BASE_URL")
+        client_kwargs = {"api_key": api_key}
+        if base_url:
+            client_kwargs["base_url"] = base_url
+        self.client = anthropic.Anthropic(**client_kwargs)
 
     def _get_common_params(self, **kwargs) -> Dict:
         """Get common parameters, avoiding sending both temperature and top_p together.
diff --git a/tests/llms/test_anthropic.py b/tests/llms/test_anthropic.py
index ae8e67d45..a0d103c2b 100644
--- a/tests/llms/test_anthropic.py
+++ b/tests/llms/test_anthropic.py
@@ -83,6 +83,39 @@ def test_both_set_prefers_temperature_over_top_p(mock_anthropic_client):
     assert "top_p" not in call_kwargs
 
 
+def test_configured_base_url_is_passed_to_client():
+    """A configured anthropic_base_url must reach the Anthropic client constructor."""
+    with patch("mem0.llms.anthropic.anthropic") as mock_anthropic:
+        config = AnthropicConfig(
+            model="claude-3-5-sonnet-20240620",
+            api_key="test-key",
+            anthropic_base_url="https://proxy.example.com",
+        )
+        AnthropicLLM(config)
+
+    assert mock_anthropic.Anthropic.call_args[1]["base_url"] == "https://proxy.example.com"
+
+
+def test_base_url_falls_back_to_env(monkeypatch):
+    """When no base_url is configured, ANTHROPIC_BASE_URL is used."""
+    monkeypatch.setenv("ANTHROPIC_BASE_URL", "https://env.example.com")
+    with patch("mem0.llms.anthropic.anthropic") as mock_anthropic:
+        config = AnthropicConfig(model="claude-3-5-sonnet-20240620", api_key="test-key")
+        AnthropicLLM(config)
+
+    assert mock_anthropic.Anthropic.call_args[1]["base_url"] == "https://env.example.com"
+
+
+def test_base_url_omitted_when_unset(monkeypatch):
+    """With no base_url anywhere, base_url must not be forced to None on the client."""
+    monkeypatch.delenv("ANTHROPIC_BASE_URL", raising=False)
+    with patch("mem0.llms.anthropic.anthropic") as mock_anthropic:
+        config = AnthropicConfig(model="claude-3-5-sonnet-20240620", api_key="test-key")
+        AnthropicLLM(config)
+
+    assert "base_url" not in mock_anthropic.Anthropic.call_args[1]
+
+
 def test_base_config_conversion_does_not_send_both(mock_anthropic_client):
     """BaseLlmConfig defaults both temperature=0.1 and top_p=0.1; Anthropic must not send both."""
     base_config = BaseLlmConfig(model="claude-3-5-sonnet-20240620", api_key="test-key")