Keep base_url in completion_params; strip at OpenAI call site.

Use get() in build_init_request so base_url remains available for gateway
URL encoding, and filter it out in remote_server when calling the SDK.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: SunnySoldier357

eval_protocol/pytest/tracing_utils.py

@@ -103,8 +103,8 @@ def build_init_request(
     if not completion_params_dict.get("model"):
         raise ValueError("Model must be provided in completion_params")
 
-    # Extract base_url from completion_params (encoded into gateway path, not sent to OpenAI SDK)
-    completion_params_base_url: Optional[str] = completion_params_dict.pop("base_url", None)
+    # Extract base_url from completion_params for tracing-gateway URL encoding
+    completion_params_base_url: Optional[str] = completion_params_dict.get("base_url")
 
     # Strip non-OpenAI fields from messages
     # Use dump_mdoel_for_chat_completion_request() to automatically exclude unsupported fields (weight, control_plane_step, reasoning_content)

tests/remote_server/remote_server.py

@@ -55,8 +55,12 @@ def _worker():
                     md = {k: v for k, v in md.items() if v is not None}
                 messages_payload.append(md)
 
-            # Spread all completion_params (model, temperature, max_tokens, etc.)
-            completion_kwargs = {"messages": messages_payload, **req.completion_params}
+            # Spread completion_params; omit base_url (client uses req.model_base_url; gateway
+            # encodes inference base_url into the tracing path via build_init_request).
+            completion_kwargs = {
+                "messages": messages_payload,
+                **{k: v for k, v in req.completion_params.items() if k != "base_url"},
+            }
 
             if req.tools:
                 completion_kwargs["tools"] = req.tools