Hey Product Hunt! 👋 I'm Liwei, a solo developer based in Finland. I built Second Brain because I kept losing ideas, forgetting promises, and never revisiting my own notes. The problem isn't capturing — it's recalling. I have hundreds of notes scattered across apps that I'll never look at again. I wanted something that actually thinks with me. The core idea is to mirror how human memory works: - Instant memories (fleeting thoughts) fade unless reinforced - Short-term memories (this week's plans) get processed and organized - Long-term memories (life experiences, core beliefs) persist and strengthen AI handles the classification automatically. You just dump your thoughts in — by typing or voice — and Second Brain figures out what it is, how it connects to your other memories, and surfaces it when relevant. A few technical choices I'm proud of: - Classification runs entirely on-device (zero API cost) - Explore queries are single-shot with hybrid recall, so token usage stays constant regardless of how many memories you have - Weekly reflections use Claude Sonnet for deeper analysis (Pro only) This is v1.1 — very early. I'm actively building based on user feedback. Tell me what resonates, what doesn't, and what you'd want to see next. Thank you for checking it out! 🙏

Second Brain

Your AI memory companion that captures, connects & recalls

Your AI memory companion that captures, connects & recalls