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.

More Info

GitHub
npm