kitfunso · 2026-04-07 · notable
Hippo Memory — biologically-inspired memory for AI agents
MIT-licensed memory system for AI coding agents that models hippocampal mechanisms: episodic/semantic two-speed storage, configurable decay, retrieval strengthening, and sleep-based consolidation.
Memory for AI agents that forgets by default and earns persistence through use -- modeled on how the hippocampus actually works.
Key specs
| License | MIT |
|---|---|
| GitHub stars | 463 |
| Dependencies | zero |
What is it?
Hippo Memory is a TypeScript library that gives AI coding agents a biologically-inspired memory layer. Instead of stuffing everything into context or a flat vector store, Hippo models seven hippocampal mechanisms: two-speed storage (a fast episodic buffer and a slower semantic store), exponential memory decay with configurable half-lives, retrieval strengthening that extends the life of memories that get used, and sleep-based consolidation that compresses related episodes into semantic patterns.
How does it work?
Memories enter a working buffer, move to the episodic store, and decay over time (default half-life: 7 days). Each retrieval strengthens the memory and pushes its expiry out. During a consolidation pass (analogous to sleep), related episodic memories merge into compact semantic memories while decayed entries are garbage-collected. Search is hybrid BM25 plus embedding similarity. The system has zero required dependencies, runs as an npm global, and auto-detects agent frameworks like Claude Code and Cursor during init.
Why does it matter?
Every long-running agent eventually forgets what it learned three sessions ago. Hippo is a clean, zero-dependency answer to that problem that does not require a vector database or a cloud service. The decay-and-strengthen model is a more principled approach than 'store everything forever' -- it naturally surfaces what matters and lets the rest fade, which is exactly what you want for a coding agent that accumulates thousands of observations over weeks.
Who is it for?
Developers running Claude Code, Cursor, or OpenClaw who want their agent to remember across sessions.
Try it
npm install -g hippo-memory && hippo init