NEXO Brain
Cognitive memory for AI agents. Open source. Free. Created by the WAzion team.
MIT License • v0.1.1 • npm • GitHub
Because we created it
Building WAzion as a single person meant working with AI agents every day. But every time you logged out, the agent forgot everything. The same corrections, the same mistakes, starting from scratch every morning.
We needed an agent that could remember. That could learn from its mistakes. That could detect when it was about to repeat something it had failed at before. That could maintain continuity between sessions as if it were the same person.
Thus NEXO Brain was born: a cognitive memory system modeled after how human memory works.
How it works
NEXO Brain implements the Atkinson-Shiffrin memory model of cognitive psychology, the same model that explains how human memory works:
Sensory Register
Capture everything that happens in the session. Discard the noise in 30 seconds. Only the relevant information moves to the next level.
Short-Term Memory
It keeps the active work context. With rehearsal (repeated use), memories are reinforced. Without use, they naturally degrade following Ebbinghaus’s curve.
Long-Term Memory
Searchable semantic vectors by meaning. Similar memories merge discriminatively: they preserve what differs, unite what overlaps. Permanent.
What it includes
76+ MCP tools
Sessions, memory, learning, credentials, guard, preferences, entities, episodic diary, and more. Everything presented as MCP tools.
Semantic search RAG
Vectors with fastembed (384 dimensions). Search by meaning, not by exact words. Relevant results in milliseconds.
Trust Score
Alignment index 0-100 that reflects the quality of the agent’s work. Corrections lower it, successes raise it. It controls internal rigor.
Metacognitive guard
Before editing code, the guard injects known errors, real schemas, and blocking rules. It prevents repeating past mistakes.
Cognitive dissonance
Detect when a new instruction contradicts a strong memory. Instead of silently overwriting, ask.
100% local
Everything in local SQLite. The vectors are computed on your machine with ONNX Runtime. Nothing leaves your computer. Zero cloud dependencies.
Installation
A command. 60 seconds. Your agent has memory.
Requires Python 3.10+ and Claude Code. The installer automatically sets up everything: MCP server, databases, cognitive maintenance processes.
Open code for everyone
NEXO Brain is open source under the MIT license. We make it available to any developer, team, or company that wants to give real memory to their AI agents.
