Handle empty input string for embedding models

python/sglang/srt/openai_api/adapter.py

@@ -1723,6 +1723,26 @@ def v1_embedding_request(all_requests, tokenizer_manager):
 
     for request in all_requests:
         prompt = request.input
+        is_invalid = False
+
+        # Check for empty/whitespace string
+        if isinstance(prompt, str):
+            is_invalid = not prompt.strip()
+        # Check for various invalid list cases: [], [""], [" "], [[]]
+        elif isinstance(prompt, list):
+            is_invalid = not prompt or (
+                len(prompt) == 1
+                and (
+                    (isinstance(prompt[0], str) and not prompt[0].strip())
+                    or (isinstance(prompt[0], list) and not prompt[0])
+                )
+            )
+        if is_invalid:
+            raise HTTPException(
+                status_code=400,
+                detail="Input cannot be empty or contain only whitespace.",
+            )
+        # End of validation
         assert (
             type(prompt) is first_prompt_type
         ), "All prompts must be of the same type in file input settings"