fix: correctly route codestral chat and FIM endpoints (#18467)

Fixed duplicate condition that made text-completion-codestral provider
unreachable. Now:
- codestral.mistral.ai/v1/chat/completions -> codestral
- codestral.mistral.ai/v1/fim/completions -> text-completion-codestral

Fixes #18464

Signed-off-by: majiayu000 <1835304752@qq.com>

litellm/litellm_core_utils/get_llm_provider_logic.py

@@ -229,10 +229,10 @@ def get_llm_provider(  # noqa: PLR0915
                     elif endpoint == "https://api.ai21.com/studio/v1":
                         custom_llm_provider = "ai21_chat"
                         dynamic_api_key = get_secret_str("AI21_API_KEY")
-                    elif endpoint == "https://codestral.mistral.ai/v1":
+                    elif endpoint == "codestral.mistral.ai/v1/chat/completions":
                         custom_llm_provider = "codestral"
                         dynamic_api_key = get_secret_str("CODESTRAL_API_KEY")
-                    elif endpoint == "https://codestral.mistral.ai/v1":
+                    elif endpoint == "codestral.mistral.ai/v1/fim/completions":
                         custom_llm_provider = "text-completion-codestral"
                         dynamic_api_key = get_secret_str("CODESTRAL_API_KEY")
                     elif endpoint == "app.empower.dev/api/v1":

tests/test_litellm/litellm_core_utils/test_codestral_provider_routing.py

@@ -0,0 +1,69 @@
+"""
+Unit tests for codestral provider routing.
+
+These tests verify that the chat and FIM endpoints for codestral
+are correctly routed to different providers:
+- Chat endpoint -> codestral provider
+- FIM endpoint -> text-completion-codestral provider
+
+Related issue: https://github.com/BerriAI/litellm/issues/18464
+"""
+import pytest
+
+import litellm
+
+
+class TestCodestralProviderRouting:
+    """Tests for codestral endpoint routing in get_llm_provider"""
+
+    def test_codestral_chat_endpoint_routes_to_codestral_provider(self):
+        """
+        Test that the codestral chat endpoint routes to the 'codestral' provider.
+
+        The chat/completions endpoint should be handled by the codestral provider.
+        """
+        model, custom_llm_provider, _, api_base = litellm.get_llm_provider(
+            model="codestral-latest",
+            api_base="https://codestral.mistral.ai/v1/chat/completions",
+        )
+
+        assert custom_llm_provider == "codestral"
+
+    def test_codestral_fim_endpoint_routes_to_text_completion_provider(self):
+        """
+        Test that the codestral FIM endpoint routes to 'text-completion-codestral'.
+
+        The fim/completions endpoint should be handled by the
+        text-completion-codestral provider for fill-in-the-middle completions.
+        """
+        model, custom_llm_provider, _, api_base = litellm.get_llm_provider(
+            model="codestral-latest",
+            api_base="https://codestral.mistral.ai/v1/fim/completions",
+        )
+
+        assert custom_llm_provider == "text-completion-codestral"
+
+    def test_codestral_endpoints_are_different_providers(self):
+        """
+        Test that chat and FIM endpoints route to different providers.
+
+        This is the core fix for issue #18464 - previously both endpoints
+        would route to 'codestral' due to duplicate conditions.
+        """
+        _, chat_provider, _, _ = litellm.get_llm_provider(
+            model="codestral-latest",
+            api_base="https://codestral.mistral.ai/v1/chat/completions",
+        )
+
+        _, fim_provider, _, _ = litellm.get_llm_provider(
+            model="codestral-latest",
+            api_base="https://codestral.mistral.ai/v1/fim/completions",
+        )
+
+        assert chat_provider != fim_provider
+        assert chat_provider == "codestral"
+        assert fim_provider == "text-completion-codestral"
+
+
+if __name__ == "__main__":
+    pytest.main([__file__, "-v"])