fix(3797): sanitize metadata for attributes to avoid silent failure

src/llama_stack/providers/utils/memory/openai_vector_store_mixin.py

@@ -23,6 +23,9 @@ from llama_stack.providers.utils.memory.vector_store import (
     content_from_data_and_mime_type,
     make_overlapped_chunks,
 )
+from llama_stack.providers.utils.vector_io.vector_utils import (
+    sanitize_metadata_for_attributes,
+)
 from llama_stack_api import (
     Chunk,
     Files,
@@ -635,7 +638,7 @@ class OpenAIVectorStoreMixin(ABC):
                     file_id=chunk.metadata.get("document_id", ""),
                     filename=chunk.metadata.get("filename", ""),
                     score=score,
-                    attributes=chunk.metadata,
+                    attributes=sanitize_metadata_for_attributes(chunk.metadata),
                     content=content,
                 )
                 data.append(response_data_item)

src/llama_stack/providers/utils/vector_io/vector_utils.py

@@ -7,6 +7,7 @@
 import hashlib
 import re
 import uuid
+from typing import Any
 
 
 def generate_chunk_id(document_id: str, chunk_text: str, chunk_window: str | None = None) -> str:
@@ -37,6 +38,28 @@ def sanitize_collection_name(name: str, weaviate_format=False) -> str:
     return s
 
 
+def sanitize_metadata_for_attributes(metadata: dict[str, Any]) -> dict[str, str | float | bool]:
+    """
+    Filter metadata to primitives for VectorStoreSearchResponse.attributes compatibility.
+
+    Converts dict[str, Any] to dict[str, str | float | bool]:
+    - Preserves: str, bool
+    - Converts: int/float -> float, list -> comma-separated string
+    - Filters: dict, None, other types
+    """
+    sanitized: dict[str, str | float | bool] = {}
+    for key, value in metadata.items():
+        if isinstance(value, bool):
+            sanitized[key] = value
+        elif isinstance(value, (int, float)):
+            sanitized[key] = float(value)
+        elif isinstance(value, str):
+            sanitized[key] = value
+        elif isinstance(value, list):
+            sanitized[key] = ", ".join(str(item) for item in value)
+    return sanitized
+
+
 class WeightedInMemoryAggregator:
     @staticmethod
     def _normalize_scores(scores: dict[str, float]) -> dict[str, float]: