NEXO Brain — Cognitive Memory for Your Agent
NEXO Brain gives your agent persistent memory modeled after human cognition. It remembers across sessions, learns from mistakes, naturally forgets what's irrelevant, and builds a trust-based relationship with you.
Setup
If your OpenClaw client shows an install action for this skill, use that first. It installs the nexo-brain package via your configured Node package manager.
If you are setting it up manually, install the cognitive engine:
npx nexo-brain
After NEXO Brain is installed, add the MCP server to your OpenClaw config (~/.openclaw/openclaw.json):
{
"mcp": {
"servers": {
"nexo-brain": {
"command": "python3",
"args": ["~/.nexo/server.py"],
"env": {
"NEXO_HOME": "~/.nexo"
}
}
}
}
}
Restart the gateway: openclaw gateway restart
What You Get
Key MCP capabilities include:
- Cognitive Memory — RAG-powered semantic search, trust scoring, sentiment detection, cognitive dissonance resolution
- Guard System — Checks "have I made this mistake before?" before every code change
- Episodic Memory — Change logs, decision logs with reasoning, session diaries for continuity
- Learnings — Error patterns and prevention rules, searchable by category
- Session Management — Startup, heartbeat, multi-session coordination
- Reminders & Followups — Track user tasks and system verification tasks separately
- Entities & Preferences — Remember people, services, URLs, and observed user preferences
- Backup & Evolution — SQLite backup with retention, self-improvement proposals
How Memory Works
NEXO implements the Atkinson-Shiffrin memory model (1968):
- Sensory Register — Raw capture, 48h retention
- Short-Term Memory — 7-day half-life, promoted if used frequently
- Long-Term Memory — 60-day half-life, semantic search by meaning
Memories naturally decay via Ebbinghaus forgetting curves. Accessing a memory reinforces it. Automated "sleep cycles" consolidate, prune, and merge memories.
Key Tools
| Tool | When to Use |
|---|---|
nexo_startup | Once at session start — registers session, returns active sessions |
nexo_heartbeat | Every interaction — updates task, checks inbox |
nexo_cognitive_retrieve | Semantic search across all memories |
nexo_guard_check | Before editing code — checks for past errors |
nexo_learning_add | After resolving an error — prevents recurrence |
nexo_session_diary_write | Before closing session — enables continuity |
nexo_cognitive_trust | After user feedback — calibrates rigor level |
Privacy
Everything stays local. Two SQLite databases in ~/.nexo/. No telemetry, no cloud APIs. Vector search runs on CPU via fastembed.