mem0

Mem0 Python SDK (v2.0.5)

New Features:

• Memory: Warn at init time when hybrid/BM25 search silently degrades to semantic-only because the configured vector store does not implement keyword_search. Affected stores: Chroma, FAISS, Cassandra, LangChain, Neptune Analytics, S3 Vectors, Supabase, TurboPuffer, Valkey (#5444)
• Memory: Add opt-in explain=True parameter to Memory.search() and AsyncMemory.search(). When enabled, each result includes a score_breakdown dict with semantic, keyword (normalized BM25), entity_boost, and temporal_boost signals so callers can understand and tune retrieval ranking (#5102)

Bug Fixes:

• Vector Stores: Normalize similarity scores to [0, 1] (higher = better) consistently across all backends. 11 adapters previously returned raw distance metrics (lower = better) — FAISS, Chroma, Milvus, Redis, Cassandra, PGVector, S3 Vectors, Supabase, Valkey, Azure MySQL, and Vertex AI Vector Search — causing incorrect ranking in multi-store setups (#5391)
• Memory: Parallelize entity boost searches in Memory.search() and AsyncMemory.search(). Previously up to 8 entities were embedded and queried sequentially (16 serial round-trips with remote embedders); all entity lookups now run concurrently, eliminating multi-second latency on entity-rich queries (#5377)
• Memory: Reject empty or whitespace-only queries in Memory.search(), AsyncMemory.search(), MemoryClient.search(), and AsyncMemoryClient.search() before any embedding or API call is made. Also strips leading/trailing whitespace from valid queries (#5258)
• LLMs: Add is_reasoning_model: Optional[bool] override to BaseLlmConfig (surfaced on OpenAILlmConfig and AzureOpenAILlmConfig). Fixes silent zero-extraction when using Azure deployments with versioned gpt-5.x names that the automatic name-based heuristic cannot recognize (#5327)
• LLMs: Fix xAI LLM provider: add XAIConfig with xai_base_url, forward tools/tool_choice in generate_response(), and parse tool_calls in the response. Previously the provider raised AttributeError at init and silently dropped tool results (#5190)
• Vector Stores: Fix PGVector ConnectionPool hang in Docker Compose environments where the app container starts before Postgres is DNS-resolvable — switched to open=False to avoid blocking constructor or silent zombie pool (#5155)
• Vector Stores: Fix PGVector sslmode handling for PostgreSQL URIs — the sslmode query parameter is now correctly extracted and forwarded when building the async connection pool (#5308)
• Vector Stores: Fix S3 Vectors list() not applying metadata filters — filtering is now done client-side after fetching, with pagination preserved and top_k applied after filtering to prevent pre-truncation of matching rows (#5018)
• Vector Stores: Fix Upstash Vector search() routing all queries to the default namespace — namespace is now passed as a top-level keyword argument to query_many() instead of inside the per-query dict where it was silently ignored (#5202)
• Core: Replace mutable default arguments with None sentinels in embedder configs and the proxy module, preventing cross-request state contamination (#5302)