# Node.js OpenTelemetry Example for Ophion

This example demonstrates how to instrument a Node.js application with OpenTelemetry and send traces to Ophion.

## Setup

```bash
# Install dependencies
npm install

# Start Ophion server (in another terminal)
# cd ~/projetos_jarvis/ophion && go run cmd/server/main.go

# Run the app with tracing
npm run trace
```

## Environment Variables

| Variable | Default | Description |
|----------|---------|-------------|
| `OTEL_EXPORTER_OTLP_ENDPOINT` | `http://localhost:8080/v1/traces` | Ophion OTLP endpoint |
| `OTEL_SERVICE_NAME` | `nodejs-example` | Service name in traces |
| `PORT` | `3000` | App HTTP port |

## Test Endpoints

```bash
# Health check
curl http://localhost:3000/health

# Get all users (generates trace)
curl http://localhost:3000/users

# Get single user
curl http://localhost:3000/users/1

# Create order (complex trace with nested spans)
curl -X POST http://localhost:3000/orders \
  -H "Content-Type: application/json" \
  -d '{"items": [{"id": 1, "qty": 2}]}'

# Trigger error (error trace)
curl http://localhost:3000/error
```

## View Traces in Ophion

```bash
# List recent traces
curl http://localhost:8080/api/v1/traces

# Get specific trace
curl http://localhost:8080/api/v1/traces/<trace_id>
```

## How It Works

1. `tracing.js` - Initializes OpenTelemetry SDK with OTLP HTTP exporter
2. Auto-instrumentation captures HTTP requests automatically
3. Manual spans in `app.js` add custom business logic traces
4. All spans are sent to Ophion's `/v1/traces` endpoint in OTLP JSON format