Fix: Support OpenAI regional API endpoints for reasoning models

Author: Sahilraj3107

openevolve/llm/openai.py

@@ -89,10 +89,21 @@ async def generate_with_context(
 
         # Check if this is an OpenAI reasoning model
         model_lower = str(self.model).lower()
+        api_base_lower = (self.api_base or "").lower()
+        #check for official OpenAI API endpoints
+        is_openai_api = (
+            api_base_lower.startswith("https://api.openai.com")
+            or api_base_lower.startswith("https://eu.api.openai.com")
+            or api_base_lower.startswith("https://apac.api.openai.com")
+            or api_base_lower.startswith("http://api.openai.com")  # Allow http for testing
+            or api_base_lower.startswith("http://eu.api.openai.com")
+            or api_base_lower.startswith("http://apac.api.openai.com")
+       )
+
         is_openai_reasoning_model = (
-            self.api_base == "https://api.openai.com/v1"
+            is_openai_api
             and model_lower.startswith(OPENAI_REASONING_MODEL_PREFIXES)
-        )
+     ) 
 
         if is_openai_reasoning_model:
             # For OpenAI reasoning models

openevolve/test_regional_endpoint.py

@@ -0,0 +1,86 @@
+"""
+Test the regional endpoint detection logic without requiring API keys
+Run this to verify the fix works correctly
+"""
+
+def test_endpoint_detection():
+    """Test that all OpenAI regional endpoints are detected correctly"""
+    
+    OPENAI_REASONING_MODEL_PREFIXES = (
+        "o1-", "o1", "o3-", "o3", "o4-",
+        "gpt-5-", "gpt-5", "gpt-oss-120b", "gpt-oss-20b",
+    )
+    
+    test_cases = [
+        # (api_base, model, should_be_reasoning_model, description)
+        ("https://eu.api.openai.com/v1", "o1-mini", True, "EU endpoint with o1-mini"),
+        ("https://api.openai.com/v1", "o1-preview", True, "US endpoint with o1-preview"),
+        ("https://apac.api.openai.com/v1", "o3-mini", True, "APAC endpoint with o3-mini"),
+        ("https://eu.api.openai.com/v1", "gpt-4", False, "EU endpoint with gpt-4"),
+        ("https://api.openai.com/v1", "gpt-3.5-turbo", False, "US endpoint with gpt-3.5"),
+        ("https://azure.openai.com/", "o1-mini", False, "Azure endpoint (not OpenAI)"),
+        ("https://fake.com/api.openai.com", "o1-mini", False, "Fake endpoint with o1"),
+        (None, "o1-mini", False, "None endpoint"),
+        ("", "o1-mini", False, "Empty endpoint"),
+        ("https://eu.api.openai.com/v1", "O1-MINI", True, "EU with uppercase model"),
+        ("HTTPS://EU.API.OPENAI.COM/v1", "o1-mini", True, "Uppercase URL"),
+    ]
+    
+    print("Testing Regional Endpoint Detection Logic")
+    print("=" * 80)
+    
+    passed = 0
+    failed = 0
+    
+    for api_base, model, expected_result, description in test_cases:
+        # This is the exact logic from your fixed code
+        model_lower = str(model).lower()
+        api_base_lower = (api_base or "").lower()
+        
+        is_openai_api = (
+            api_base_lower.startswith("https://api.openai.com")
+            or api_base_lower.startswith("https://eu.api.openai.com")
+            or api_base_lower.startswith("https://apac.api.openai.com")
+            or api_base_lower.startswith("http://api.openai.com")
+            or api_base_lower.startswith("http://eu.api.openai.com")
+            or api_base_lower.startswith("http://apac.api.openai.com")
+        )
+        
+        is_openai_reasoning_model = (
+            is_openai_api
+            and model_lower.startswith(OPENAI_REASONING_MODEL_PREFIXES)
+        )
+        
+        # Determine which parameter would be used
+        param_used = "max_completion_tokens" if is_openai_reasoning_model else "max_tokens"
+        expected_param = "max_completion_tokens" if expected_result else "max_tokens"
+        
+        # Check if result matches expectation
+        if is_openai_reasoning_model == expected_result:
+            status = "✅ PASS"
+            passed += 1
+        else:
+            status = "❌ FAIL"
+            failed += 1
+        
+        print(f"\n{status} | {description}")
+        print(f"  API Base: {api_base}")
+        print(f"  Model: {model}")
+        print(f"  is_openai_api: {is_openai_api}")
+        print(f"  is_reasoning_model: {is_openai_reasoning_model}")
+        print(f"  Parameter used: {param_used}")
+        print(f"  Expected: {expected_param}")
+    
+    print("\n" + "=" * 80)
+    print(f"Results: {passed} passed, {failed} failed out of {len(test_cases)} tests")
+    
+    if failed == 0:
+        print("🎉 All tests PASSED! The fix is working correctly.")
+        return True
+    else:
+        print("⚠️ Some tests FAILED! Please review the logic.")
+        return False
+
+if __name__ == "__main__":
+    success = test_endpoint_detection()
+    exit(0 if success else 1)