Collectivus

Zero-dependency OTLP/HTTP JSON collector that writes to JSONL files.

Installation

npm install collectivus

Usage

CLI

# Start with defaults (port 4318, output ./otel-data)
npx collectivus

# Custom port and output directory
npx collectivus --port 8080 --output /var/log/otel

Configuration can also be supplied via environment variables, which is convenient when wrapping the CLI in a process manager (launchd, systemd, etc.) that passes config via EnvironmentVariables:

• COLLECTIVUS_PORT — listen port (default 4318)
• COLLECTIVUS_OUTPUT_DIR — JSONL output directory (default ./otel-data)

Argv takes precedence over environment variables when both are set.

The CLI handles SIGINT and SIGTERM for graceful shutdown.

Programmatic

import { Collector } from 'collectivus'

const collector = new Collector({
  port: 4318,
  outputDir: './otel-data'
})

await collector.start()
console.log('Collector running')

// To stop
await collector.stop()

Endpoints

• POST /v1/traces - Receive trace data
• POST /v1/metrics - Receive metrics data
• POST /v1/logs - Receive log data

Output

Data is written to JSONL files in the output directory:

otel-data/
├── traces/
│   └── YYYY-MM-DD.jsonl
├── metrics/
│   └── YYYY-MM-DD.jsonl
└── logs/
    └── YYYY-MM-DD.jsonl

Each line is a JSON object representing the received payload.

Verification

# Start the collector
node bin/cli.js

# Send test data
curl -X POST localhost:4318/v1/traces -H 'Content-Type: application/json' -d '{"test": true}'

# Check output
cat otel-data/traces/$(date -u +%F).jsonl

License

MIT