Virtual Engineer
AI-assisted chiller troubleshooting demo powered by MongoDB Atlas. A field engineer describes a symptom; an LLM agent retrieves operational facts and knowledge through MCP tools, with live visibility into MongoDB retrieval patterns in the demo UI.
What it demonstrates
- Deterministic grounding — asset resolution, alarms, telemetry, service history
- Probabilistic retrieval — Atlas Vector Search and hybrid case search
- Real-time transparency — query patterns, pipelines, and latency in the UI
- Two demo paradigms — Evidence Board (technical) and Field Chat with X-ray (business)
Architecture
Demo UI (React) → LLM Agent (SSE) → MCP Server → Atlas
├── Database (operational data)
├── Vector Search (knowledge, cases)
└── Atlas Search (case notes)
See docs/architecture.md for details.
Prerequisites
- Node.js 18+
- MongoDB Atlas cluster
- OpenAI or Anthropic API key (for chat)
Quick start
cp .env.example .env # add MONGODB_URI, OPENAI_API_KEY
npm install
npm run seed:drop # load sample data into virtual_engineer database
# Terminal 1 — backend (MCP + chat API)
npm run mcp:dev
# Terminal 2 — demo UI
cd frontend && npm install && npm run dev
Open http://localhost:5173.
Demo scenarios
| Chiller | Alarm | Story |
|---|---|---|
| CH-ATL-003 | A1.01 | Hero — repeat motor temperature fault |
| CH-DAL-002 | 207 | High condenser pressure / cooling tower |
| CH-PHX-005 | Co.A1 | Compressor board communication loss |
| CH-ATL-001 | — | Stable unit (negative control) |
Starter prompts are on the Overview tab. See scripts/data/README.md for the full scenario matrix.
Scripts
| Command | Purpose |
|---|---|
npm run mcp:dev |
Start MCP server + chat API (:3100) |
npm run seed:drop |
Reseed Atlas with sample data |
npm run test:connectivity |
Smoke tests (server must be running) |
cd frontend && npm run dev |
Demo UI dev server (:5173) |
Documentation
| Doc | Purpose |
|---|---|
| docs/runbook.md | Operations, env vars, troubleshooting |
| docs/test-plan.md | Test commands and dry-run scenarios |
| docs/indexes.md | Atlas Search / Vector Search index definitions |
| docs/phase-status.md | Build phase tracker |
License
MIT
Requirements
Product and design rationale: Virtual Engineer High-Level Requirements and Design Logic.md
