Lorenze/OpenAI base url backwards support (#3723)

* fix: enhance OpenAICompletion class base URL handling

- Updated the base URL assignment in the OpenAICompletion class to prioritize the new `api_base` attribute and fallback to the environment variable `OPENAI_BASE_URL` if both are not set.
- Added `api_base` to the list of parameters in the OpenAICompletion class to ensure proper configuration and flexibility in API endpoint management.

* feat: enhance OpenAICompletion class with api_base support

- Added the `api_base` parameter to the OpenAICompletion class to allow for flexible API endpoint configuration.
- Updated the `_get_client_params` method to prioritize `base_url` over `api_base`, ensuring correct URL handling.
- Introduced comprehensive tests to validate the behavior of `api_base` and `base_url` in various scenarios, including environment variable fallback.
- Enhanced test coverage for client parameter retrieval, ensuring robust integration with the OpenAI API.

* fix: improve OpenAICompletion class configuration handling

- Added a debug print statement to log the client configuration parameters during initialization for better traceability.
- Updated the base URL assignment logic to ensure it defaults to None if no valid base URL is provided, enhancing robustness in API endpoint configuration.
- Refined the retrieval of the `api_base` environment variable to streamline the configuration process.

* drop print

lib/crewai/src/crewai/llms/providers/openai/completion.py

@@ -65,6 +65,7 @@ class OpenAICompletion(BaseLLM):
         self.client_params = client_params
         self.timeout = timeout
         self.base_url = base_url
+        self.api_base = kwargs.pop("api_base", None)
 
         super().__init__(
             model=model,
@@ -106,7 +107,10 @@ class OpenAICompletion(BaseLLM):
             "api_key": self.api_key,
             "organization": self.organization,
             "project": self.project,
-            "base_url": self.base_url,
+            "base_url": self.base_url
+            or self.api_base
+            or os.getenv("OPENAI_BASE_URL")
+            or None,
             "timeout": self.timeout,
             "max_retries": self.max_retries,
             "default_headers": self.default_headers,
@@ -239,6 +243,7 @@ class OpenAICompletion(BaseLLM):
             "provider",
             "api_key",
             "base_url",
+            "api_base",
             "timeout",
         }
 

lib/crewai/tests/llms/openai/test_openai.py

@@ -407,3 +407,77 @@ def test_extra_arguments_are_passed_to_openai_completion():
         assert call_kwargs['max_tokens'] == 1000
         assert call_kwargs['top_p'] == 0.5
         assert call_kwargs['model'] == 'gpt-4o'
+
+
+
+def test_openai_get_client_params_with_api_base():
+    """
+    Test that _get_client_params correctly converts api_base to base_url
+    """
+    llm = OpenAICompletion(
+        model="gpt-4o",
+        api_base="https://custom.openai.com/v1",
+    )
+    client_params = llm._get_client_params()
+    assert client_params["base_url"] == "https://custom.openai.com/v1"
+
+def test_openai_get_client_params_with_base_url_priority():
+    """
+    Test that base_url takes priority over api_base in _get_client_params
+    """
+    llm = OpenAICompletion(
+        model="gpt-4o",
+        base_url="https://priority.openai.com/v1",
+        api_base="https://fallback.openai.com/v1",
+    )
+    client_params = llm._get_client_params()
+    assert client_params["base_url"] == "https://priority.openai.com/v1"
+
+def test_openai_get_client_params_with_env_var():
+    """
+    Test that _get_client_params uses OPENAI_BASE_URL environment variable as fallback
+    """
+    with patch.dict(os.environ, {
+        "OPENAI_BASE_URL": "https://env.openai.com/v1",
+    }):
+        llm = OpenAICompletion(model="gpt-4o")
+        client_params = llm._get_client_params()
+        assert client_params["base_url"] == "https://env.openai.com/v1"
+
+def test_openai_get_client_params_priority_order():
+    """
+    Test the priority order: base_url > api_base > OPENAI_BASE_URL env var
+    """
+    with patch.dict(os.environ, {
+        "OPENAI_BASE_URL": "https://env.openai.com/v1",
+    }):
+        # Test base_url beats api_base and env var
+        llm1 = OpenAICompletion(
+            model="gpt-4o",
+            base_url="https://base-url.openai.com/v1",
+            api_base="https://api-base.openai.com/v1",
+        )
+        params1 = llm1._get_client_params()
+        assert params1["base_url"] == "https://base-url.openai.com/v1"
+
+        # Test api_base beats env var when base_url is None
+        llm2 = OpenAICompletion(
+            model="gpt-4o",
+            api_base="https://api-base.openai.com/v1",
+        )
+        params2 = llm2._get_client_params()
+        assert params2["base_url"] == "https://api-base.openai.com/v1"
+
+        # Test env var is used when both base_url and api_base are None
+        llm3 = OpenAICompletion(model="gpt-4o")
+        params3 = llm3._get_client_params()
+        assert params3["base_url"] == "https://env.openai.com/v1"
+
+def test_openai_get_client_params_no_base_url():
+    """
+    Test that _get_client_params works correctly when no base_url is specified
+    """
+    llm = OpenAICompletion(model="gpt-4o")
+    client_params = llm._get_client_params()
+    # When no base_url is provided, it should not be in the params (filtered out as None)
+    assert "base_url" not in client_params or client_params.get("base_url") is None