Hippo v0.21.0: Biologically-Inspired Memory for AI Agents with Multi-Tool Support

Hippo is a biologically-inspired memory system for AI agents that addresses the problem of agents forgetting everything between sessions. Unlike solutions that just save everything, Hippo implements decay, retrieval strengthening, and consolidation mechanics similar to human memory.

Core Features

Works with: Claude Code, Codex, Cursor, OpenClaw, OpenCode, Pi, and any CLI agent. Imports from: ChatGPT, Claude (CLAUDE.md), Cursor (.cursorrules), and any markdown. Storage uses SQLite backbone with markdown/YAML mirrors that are git-trackable and human-readable. Zero runtime dependencies, requiring only Node.js 22.5+. Optional embeddings via @xenova/transformers.

Setup and Usage

Install with npm install -g hippo-memory. For single project setup: hippo init. For all projects at once: hippo init --scan ~ which finds every git repo under your home directory, creates a .hippo/ store in each, and seeds it with lessons from commit history.

After setup, hippo sleep runs automatically at session end via agent hooks and performs five operations:

• Learns from today's git commits
• Imports new entries from Claude Code MEMORY.md files
• Consolidates memories (decay, merge, prune)
• Deduplicates near-identical memories (keeps the stronger copy)
• Shares high-value lessons to the global store so they surface in every project

Manual usage includes: hippo remember "FRED cache silently dropped the tips_10y series" --tag error and hippo recall "data pipeline issues" --budget 2000.

What's New in v0.21.0

hippo setup — one command for every tool. Detects Claude Code, OpenCode, OpenClaw, Codex, Cursor, and Pi on your machine and installs all available SessionEnd + SessionStart hooks in one pass. Idempotent and safe to re-run.

OpenCode hooks: SessionEnd + SessionStart install into ~/.config/opencode/opencode.json (OpenCode added Claude-Code-compatible hooks in Jan 2026). You now see consolidation output — new SessionStart hook prints the previous session's hippo sleep output between banners on next startup.

Recent Updates

v0.20.3 added visible confirmation on session-end sleep. The installed SessionEnd hook now echoes [hippo] consolidating memory... before running and [hippo] sleep complete or [hippo] sleep failed after. Existing installs need reinstall (hippo hook uninstall claude-code && hippo hook install claude-code) to pick up the new command.

v0.20.2 changed Claude Code hook to use SessionEnd instead of Stop. Earlier versions ran hippo sleep after every assistant turn; now it runs once at session exit. Re-running hippo hook install claude-code migrates existing Stop entries automatically. Hook installation and initialization no longer create accidental CLAUDE.md files — they only patch agent-instruction files that already exist.