We Built the First AI Agent Memory System With Zero LLM Calls — Here's the Architecture

We Built the First AI Agent Memory System With Zero LLM Calls Every AI memory system on the market makes the same architectural choice: send your text to an LLM for extraction before storing it. Mem0 calls GPT-4o. Zep makes multiple async LLM calls. Cognee uses LLMs for knowledge extraction. Letta's entire memory engine is an LLM. That means every single memory.store() costs ~$0.01, takes 500ms-2s, and produces non-deterministic results. At 100K memories/month, you're paying $1,000-3,000 just to remember things . We asked: what if you didn't need an LLM at all? The result is Mnemosyne — the first cognitive memory OS for AI agents with zero LLM calls in the entire ingestion pipeline. 33 features, 5 cognitive layers, $0 per memory stored. MIT licensed. The Cost Table Nobody Wants You to See System LLM Required? Cost per memory 100K memories/mo Mnemosyne No $0.00 ~$60 (infra only) Mem0 Yes (GPT-4o) ~$0.01 $1,000-3,000 Zep Yes (multiple calls) ~$0.01 $1,000-2,000 Cognee Yes (extraction) ~$