Mem0

Pricing trap: knowledge graph is Pro-tier-only at $249/mo. Free and $19/mo Starter are pure vector search. Strengths: largest GitHub community (~48K stars), most third-party tutorials, broad framework integrations (LangChain, CrewAI, AutoGen, LlamaIndex). Trade: lowest LongMemEval among production systems, US-default hosting, knowledge graph priced as premium. Pick if framework integrations matter or self-host is required.