Problem

When build_fulltext_query in falkordb_driver.py receives a query where all words are filtered out as stopwords, sanitized_query becomes an empty string. The method still constructs the full query string, producing:

(@group_id:"standups") ()

The trailing () is invalid RediSearch syntax and causes FalkorDB to throw:

RediSearch: Syntax error at offset 24 near standups

This error surfaces during graphiti.add_episode() when graphiti internally searches for existing nodes to merge with, and the extracted entity name consists entirely of stopwords.

Steps to reproduce

1. Use a FalkorDB-backed Graphiti instance with a group_id set (e.g. "standups")
2. Ingest an episode where the LLM extracts an entity whose name is composed entirely of RediSearch stopwords
3. Graphiti calls build_fulltext_query with that entity name — all words are stripped, sanitized_query = ""
4. The method constructs "(@group_id:\"standups\") ()" and passes it to FalkorDB
5. FalkorDB raises a syntax error

Fix

Add a guard for the empty-query case before constructing full_query:

if not sanitized_query:
    return ''

Insert this before the existing max_query_length check in build_fulltext_query (~line 419 in falkordb_driver.py).

Version

• graphiti-core: 0.28.2
• FalkorDB driver