MemMachine: A Ground-Truth-Preserving Memory System for Personalized AI Agents

MemMachine is an open-source memory system for AI agents that preserves conversational ground truth and achieves superior accuracy-efficiency tradeoffs compared to existing solutions. The system integrates short-term, long-term episodic, and profile memory while using 80% fewer input tokens than comparable systems like Mem0.

• →MemMachine achieves 93.0% accuracy on LongMemEvalS benchmark with significant retrieval-stage optimizations.
• →The system uses 80% fewer input tokens compared to Mem0 under matched conditions.
• →GPT-5-mini paired with optimized prompts exceeds GPT-5 performance by 2.6% while being more cost-efficient.
• →Contextualized retrieval that expands nucleus matches with surrounding context improves recall across multiple dialogue turns.
• →The companion Retrieval Agent achieves over 92% accuracy on complex multi-hop reasoning tasks under noisy conditions.