Engineering OS

Name: engineering-os
Author: engineering-os

Your AI finally remembers your codebase.

Stop re-explaining your architecture every session. Engineering OS gives Claude Code, Cursor, Codex, and any MCP-compatible AI code editor the memory they've always been missing. They finally write code like someone who actually knows your project.

npm install -g engineering-os
cd your-project
eos init --claude

That's it. Your AI now has persistent project knowledge. Permanently.

Engineering OS Demo

The Problem

Every new session, your AI re-explores files, re-debates decisions you already made, and has no idea your frontend talks to three backend services.

Today (without Engineering OS)	With Engineering OS
"Let me explore your project structure..."	Already knows. Starts working immediately.
"Should we use Redux or Zustand?"	"You decided on Zustand last month. Here's why."
Suggests code that breaks another service	Sees the dependency graph. Avoids breakage.
You explain the same gotcha every session	Learned it once. Warns you proactively.
grep-ing for 30s trying to find that function	Instant answer. It's pre-indexed.
Security review is something you do "later"	Already scanned. Flags issues as you code.

How It Works

AI Code Editor (Claude Code / Cursor / Codex / Any MCP Client)
    │ MCP Protocol (stdio)
    ▼
Engineering OS (runs on your machine, zero cloud)
    ├── Code Search (FTS5 + BM25, instant results)
    ├── Service Graph (cross-repo topology)
    ├── Skill Memory (learns from every session)
    ├── Decision Records (never re-debates)
    ├── Convention Enforcement (your rules, always followed)
    └── Security Scanner (OWASP, CVE, compliance)
    │
    ▼
Your Codebase + Linked Repos (SQLite, 100% local)

eos init indexes your codebase, discovers architecture, builds the service graph
Your AI tool connects automatically via MCP (no manual config)
AI calls eos_context and gets full project knowledge instantly
AI calls eos_learn when it discovers something. That knowledge persists forever.

Quick Start

# Install
npm install -g engineering-os

# Point it at your project
cd your-project
eos init --claude --cursor

# Link sibling services (optional)
eos link backend-api ../backend-api
eos link ml-pipeline ../ml-service

# Keep it fresh
eos refresh --incremental

What You Get

Never explains twice. Architecture, routes, conventions, and decisions persist across every session.
Sees all your repos. Link your mobile app, BFF, backend, ML pipeline. Your AI sees the full picture.
Learns your tricks. That weird workaround? That gotcha with uploads? Remembered. Forever.
Catches security issues. Secrets, injection flaws, known CVEs in your dependencies. Scans continuously.
Finds code instantly. Pre-indexed search. Ask "where's the auth middleware?" and get the answer in milliseconds.
Maps your architecture. Auto-detects how your services connect, which layers exist, what patterns you follow.

CLI Commands

Command	What it does
`eos init --claude --cursor`	Index your project + generate AI context files
`eos serve`	Start the MCP server
`eos refresh --incremental`	Update knowledge after code changes
`eos link <name> <path>`	Link a sibling repository
`eos workspace init`	Create team-shared config (checked into git)
`eos index --watch`	Continuous re-indexing as you code
`eos status`	Show knowledge health and drift

Works With

Claude Code (Anthropic)
Cursor
Codex (OpenAI)
VS Code
Any editor that speaks MCP protocol

Team Sharing

Create eos.workspace.yaml and check it into git. Your entire team shares the same conventions and decisions:

name: my-project
type: monorepo
org: my-company

repos:
  - name: api-gateway
    path: ../api-gateway
    role: gateway
  - name: backend
    path: ../backend-service
    role: bff

conventions:
  - name: error-handling
    rule: "Use Result<T> pattern. Only controllers throw HTTP exceptions."
  - name: state
    rule: "Zustand only. No Redux. One store per domain."

decisions:
  - title: "Redis for sessions"
    decision: "Redis Cluster for session management"
    rationale: "Sub-ms reads, horizontal scaling, built-in expiry"

Troubleshooting

MCP Error `-32000` in Claude Code

Node.js version mismatch. The native SQLite module was compiled for a different Node version.

# Fix: rebuild for your current Node
npm rebuild better-sqlite3

# Or just reinstall
npm install -g engineering-os

Why: If you use nvm and your shell defaults to a different Node version than what installed Engineering OS, the native binary won't load. Make sure both match.

Requirements

Node.js >= 18 (LTS 20 or 22 recommended)
No API keys, no cloud, nothing external

Documentation

Full docs with API reference, guides, and tool list: engineering-os.github.io/engineering-os

Architecture

packages/
├── shared/           # Shared types
├── core/             # MCP server, knowledge engine, security, workflows
├── cli/              # CLI (the `eos` command)
├── adapter-claude/   # Claude Code plugin (11 skills)
├── adapter-cursor/   # Cursor rules generator
├── adapter-vscode/   # VS Code extension
└── engineering-os/   # Single npm package (bundles everything)

License

Apache 2.0 — see LICENSE