cortex-engine

Persistent memory for AI agents. Open source, LLM-agnostic, works with any MCP client.

What It Does

Most AI agents forget everything when the session ends. cortex-engine fixes that — it gives agents a persistent memory layer that survives across sessions, models, and runtimes.

• Semantic memory — store and retrieve observations, beliefs, questions, and hypotheses as interconnected nodes
• Belief tracking — agents hold positions that update when new evidence contradicts them
• Two-phase dream consolidation — NREM compression (cluster, refine, create) + REM integration (connect, score, abstract) — modeled on biological sleep stages
• Goal-directed cognition — goal_set creates desired future states that generate forward prediction error, biasing consolidation and exploration toward what matters
• Neuroscience-grounded retrieval — GNN neighborhood aggregation, query-conditioned spreading activation, multi-anchor Thousand Brains voting, epistemic foraging
• Information geometry — locally-adaptive clustering thresholds that respect embedding space curvature, schema congruence scoring
• Graph health metrics — Fiedler value (algebraic connectivity) measures knowledge integration; PE saturation detection prevents identity model ossification
• Spaced repetition (FSRS) — interval-aware scheduling with consolidation-state-dependent decay profiles
• Embeddings — pluggable providers (built-in, OpenAI, Vertex AI, Ollama) — no external service required by default
• LLM-agnostic — pluggable LLM providers: Ollama (free/local), Gemini, DeepSeek, Hugging Face, OpenRouter, OpenAI, or any OpenAI-compatible API
• Agent dispatch — agent_invoke lets your agent spawn cheap, cortex-aware sub-tasks using any configured LLM. Knowledge compounds across sessions.
• MCP server — 27 cognitive tools (query, observe, believe, wander, dream, goal_set, agent_invoke, etc.) over the Model Context Protocol

The result: personality and expertise emerge from accumulated experience, not system prompts. An agent with 200 observations about distributed systems doesn't need to be told "you care about distributed systems." It just knows.

Works with Claude Code, Cursor, Windsurf, or any MCP-compatible client. Runs locally (SQLite) or in the cloud (Firestore + Cloud Run).

Architecture

Module	Role
core	Foundational types, config, and shared utilities
engines	Cognitive processing: memory consolidation, FSRS, graph traversal
stores	Persistence layer — SQLite (local) and Firestore (cloud)
mcp	MCP server and tool definitions
cognitive	Higher-order cognitive operations (dream, wander, validate)
triggers	Scheduled and event-driven triggers
bridges	Adapters for external services and APIs
providers	Embedding and LLM provider implementations
bin	Entry points: serve.js (HTTP + MCP), cli.js (admin CLI)

Quick Start

npm install cortex-engine@0.9.0
npx fozikio init my-agent
cd my-agent
npx fozikio serve   # starts MCP server

Your agent now has 27 cognitive tools. The generated .mcp.json is version-pinned and platform-aware (Windows cmd /c wrapper handled automatically).

See the Quick Start wiki page for the full 5-minute setup.

Multi-Agent

npx fozikio agent add researcher --description "Research agent"
npx fozikio agent add trader --description "Trading signals"
npx fozikio agent generate-mcp   # writes .mcp.json with scoped servers

Each agent gets isolated memory via namespaces. See the Architecture wiki page for details.

Agent-First Setup

The fastest path: open an AI agent in an empty directory and say "set up a cortex workspace." The agent runs npx fozikio init, reads the generated files, and is immediately productive. See the Installation wiki page for the full guide.

CLI

npx fozikio serve              # start MCP server
npx fozikio health             # memory health report
npx fozikio vitals             # behavioral vitals and prediction error
npx fozikio wander             # walk through the memory graph
npx fozikio wander --from "auth"  # seeded walk from a topic
npx fozikio maintain fix       # scan and repair data issues
npx fozikio report             # weekly quality report

Development

npm run dev       # tsc --watch
npm test          # vitest run
npm run test:watch

Environment Variables

Variable	Required	Description
CORTEX_API_TOKEN	Optional	Used by the cortex-telemetry hook to send retrieval feedback to the cortex API. Not required to run the MCP server.

Additional variables are required depending on which providers you enable (Firestore, Vertex AI, OpenAI, etc.). See docs/ for provider-specific configuration.

Rules, Skills & Agents

fozikio init automatically installs safety rules, skills, and agent definitions from the fozikio.json manifest into the target workspace.

Safety Rules (Reflex)

cortex-engine ships with Reflex rules — portable YAML-based guardrails that work across any agent runtime, not just Claude Code.

Rule	Event	What It Does
cognitive-grounding	prompt_submit	Nudges the agent to call query() before evaluation, design, review, or creation work
observe-first	file_write / file_edit	Warns if writing to memory directories without calling observe() or query() first
note-about-doing	prompt_submit	Suggests capturing new threads of thought with thread_create()

Rules live in reflex-rules/ as standard Reflex YAML. They're portable — use them with Claude Code, Cursor, Codex, or any runtime with a Reflex adapter. See @fozikio/reflex for the full rule format and tier enforcement.

Claude Code users also get platform-specific hooks (in hooks/) for telemetry, session lifecycle, and project board gating. These are runtime adapters, not rules — they handle side effects that the declarative rule format doesn't cover.

To customize: Edit the YAML rule files directly, or set allow_disable: true and disable them via Reflex config.

Skills

Skills are invocable workflows that agents can use via /skill-name.

Skill	When to Use	What It Provides
cortex-memory	Query, record, and review work	Full memory workflow — query/observe patterns, belief tracking, memory-grounded code review, session patterns

Agents

Agent	Description
cortex-researcher	Deep research agent that queries cortex before external sources, observes novel findings back into memory

How Auto-Install Works

1. fozikio init reads fozikio.json from the package root
2. Copies hooks, skills, and Reflex rules into the target workspace
3. Missing source files are skipped with a warning — init never fails due to missing assets

Plugin Ecosystem

cortex-engine ships with 26 cognitive tools out of the box. Plugins add more: Fozikio Plugin Docs

Plugin	What It Adds
@fozikio/tools-threads	Thought threads — create, update, resolve ongoing lines of thinking
@fozikio/tools-journal	Session journaling — structured reflections that persist
@fozikio/tools-content	Content pipeline — draft, review, publish workflow
@fozikio/tools-evolution	Identity evolution — track how the agent's personality changes over time
@fozikio/tools-social	Social cognition — interaction patterns, engagement tracking
@fozikio/tools-graph	Graph analysis — memory connections, clustering, visualization data
@fozikio/tools-maintenance	Memory maintenance — cleanup, deduplication, health checks
@fozikio/tools-vitals	Vitals tracking — agent health metrics and operational signals
@fozikio/tools-reasoning	Cognitive reasoning — abstraction, contradiction detection, surfacing

Install any plugin: npm install @fozikio/tools-threads — cortex-engine auto-discovers and loads installed plugins.

Documentation

• Wiki — Installation, architecture, plugin authoring, MCP integration, deployment, FAQ
• Discussions — Ask questions, share what you've built
• Contributing — How to contribute
• Project Board — Roadmap and active work
• Security — Report vulnerabilities

Related Projects

• @fozikio/reflex — Portable safety guardrails for agents. Rules as data, not code.
• sigil — Agent control surface. Signals and gestures, not conversations.
• fozikio.com — Documentation and guides
• r/fozikio — Community

License

MIT — see LICENSE