[Inference Providers] fix inference with URL endpoints

src/huggingface_hub/inference/_client.py

@@ -884,7 +884,13 @@ def chat_completion(
         payload_model = model or self.model
 
         # Get the provider helper
-        provider_helper = get_provider_helper(self.provider, task="conversational", model=payload_model)
+        provider_helper = get_provider_helper(
+            self.provider,
+            task="conversational",
+            model=model_id_or_url
+            if model_id_or_url is not None and model_id_or_url.startswith(("http://", "https://"))
+            else payload_model,
+        )
 
         # Prepare the payload
         parameters = {

src/huggingface_hub/inference/_generated/_async_client.py

@@ -924,7 +924,13 @@ async def chat_completion(
         payload_model = model or self.model
 
         # Get the provider helper
-        provider_helper = get_provider_helper(self.provider, task="conversational", model=payload_model)
+        provider_helper = get_provider_helper(
+            self.provider,
+            task="conversational",
+            model=model_id_or_url
+            if model_id_or_url is not None and model_id_or_url.startswith(("http://", "https://"))
+            else payload_model,
+        )
 
         # Prepare the payload
         parameters = {

src/huggingface_hub/inference/_providers/__init__.py

@@ -147,7 +147,11 @@ def get_provider_helper(
         ValueError: If provider or task is not supported
     """
 
-    if model is None and provider in (None, "auto"):
+    if (
+        model is None
+        and provider in (None, "auto")
+        or (model is not None and model.startswith(("http://", "https://")))
+    ):
         provider = "hf-inference"
 
     if provider is None: