fix(ollama): build the chat url from any api_base form

The /api/generate suffix was only stripped from the api_base argument, so a
global litellm.api_base ending in /api/generate still produced
/api/generate/api/chat for rerouted tool requests. Normalize in
OllamaChatConfig.get_complete_url instead, which every api_base source goes
through, and drop the extra rebind in completion(). Trailing slashes no longer
produce //api/chat either

litellm/llms/ollama/chat/transformation.py

@@ -222,14 +222,8 @@ class OllamaChatConfig(BaseConfig):
 
         Some providers need `model` in `api_base`
         """
-        if api_base is None:
-            api_base = "http://localhost:11434"
-        if api_base.endswith("/api/chat"):
-            url = api_base
-        else:
-            url = f"{api_base}/api/chat"
-
-        return url
+        base: Final = (api_base or "http://localhost:11434").rstrip("/").removesuffix("/api/generate")
+        return base if base.endswith("/api/chat") else f"{base}/api/chat"
 
     def transform_request(
         self,

litellm/main.py

@@ -5309,8 +5309,6 @@ def completion(
         )
         if custom_llm_provider == "ollama" and (tools or functions):
             custom_llm_provider = "ollama_chat"  # rebind-ok: /api/generate has no native tool calling
-            if api_base is not None:
-                api_base = api_base.rstrip("/").removesuffix("/api/generate")  # rebind-ok: chat path
         elif custom_llm_provider == "ollama":
             tools = None  # rebind-ok: empty tools must not change plain completion behavior
             functions = None  # rebind-ok: empty functions must not change plain completion behavior

tests/test_litellm/llms/ollama/test_ollama_chat_transformation.py

@@ -944,3 +944,23 @@ class TestOllamaToolCallTransformation:
         assert tool_msg["content"] == "Sunny, 72°F"
         assert "tool_call_id" in tool_msg, "tool_call_id must be forwarded to Ollama"
         assert tool_msg["tool_call_id"] == "call_abc123"
+
+
+@pytest.mark.parametrize(
+    ("api_base", "expected_url"),
+    [
+        (None, "http://localhost:11434/api/chat"),
+        ("http://ollama.example:11434", "http://ollama.example:11434/api/chat"),
+        ("http://ollama.example:11434/", "http://ollama.example:11434/api/chat"),
+        ("http://ollama.example:11434/api/chat", "http://ollama.example:11434/api/chat"),
+        ("http://ollama.example:11434/api/chat/", "http://ollama.example:11434/api/chat"),
+        ("http://ollama.example:11434/api/generate", "http://ollama.example:11434/api/chat"),
+        ("http://ollama.example:11434/prefix/api/generate/", "http://ollama.example:11434/prefix/api/chat"),
+    ],
+)
+def test_get_complete_url_points_at_chat_endpoint(api_base, expected_url):
+    url = OllamaChatConfig().get_complete_url(
+        api_base=api_base, api_key=None, model="qwen3.8:27b", optional_params={}, litellm_params={}
+    )
+
+    assert url == expected_url