Pino is the fastest Node.js logger — used by Fastify, NestJS, and high-throughput services. The LogFlow Pino integration works as a destination stream, so Pino continues writing JSON at full speed and LogFlow picks it up automatically.

Prerequisites

Node.js 18+ app using Pino (pino v6, v7, v8, or v9)
A LogFlow account
Your API key from Settings → API Key

Step 1 — Install

npm install @getlogflow/js

Step 2 — Create the logger

import pino from 'pino'
import { createLogFlowStream } from '@getlogflow/js/transports/pino'

const logger = pino(
  { level: 'info' },
  createLogFlowStream({
    apiKey: process.env.LOGFLOW_API_KEY!,
    service: 'api',             // rename to your service
    environment: process.env.NODE_ENV,
    release: process.env.APP_VERSION, // optional
  })
)

export default logger

Add your API key to .env:

LOGFLOW_API_KEY=lf_your_api_key_here

Step 3 — Log with structured data

Pino encourages putting data in the first object and the message second:

logger.info({ userId: 'u_123', plan: 'starter' }, 'User signed up')
logger.warn({ ip: req.ip, limit: 100 }, 'Rate limit approaching')
logger.error({ err, orderId: 'ord_456' }, 'Payment failed')

All fields are preserved in LogFlow as searchable attributes.

Step 4 — Keep console output too (multi-stream)

In development you likely want Pino to print to stdout while also sending to LogFlow:

import pino from 'pino'
import pinoPretty from 'pino-pretty'
import { createLogFlowStream } from '@getlogflow/js/transports/pino'

const isDev = process.env.NODE_ENV !== 'production'

const logger = isDev
  // Development: pretty print to console only
  ? pino({ level: 'debug' }, pinoPretty())
  // Production: send to LogFlow
  : pino(
      { level: 'info' },
      createLogFlowStream({ apiKey: process.env.LOGFLOW_API_KEY!, service: 'api' })
    )

Or use pino-multi-stream to send to both simultaneously:

import pino from 'pino'
import { multistream } from 'pino-multi-stream'
import { createLogFlowStream } from '@getlogflow/js/transports/pino'

const logger = pino(
  { level: 'info' },
  multistream([
    { stream: process.stdout },
    { stream: createLogFlowStream({ apiKey: process.env.LOGFLOW_API_KEY!, service: 'api' }) },
  ])
)

Step 5 — Fastify integration

Fastify has built-in Pino support. Pass the LogFlow stream as Fastify's logger:

import Fastify from 'fastify'
import { createLogFlowStream } from '@getlogflow/js/transports/pino'

const app = Fastify({
  logger: {
    level: 'info',
    stream: createLogFlowStream({
      apiKey: process.env.LOGFLOW_API_KEY!,
      service: 'api',
      environment: process.env.NODE_ENV,
    }),
  },
})

// Fastify's built-in request logging now goes to LogFlow
app.get('/users/:id', async (request, reply) => {
  request.log.info({ userId: request.params.id }, 'Fetching user')
  // ...
})

Fastify automatically logs every request with method, url, status, and response time.

Step 6 — Trace ID correlation

Add a traceId to all logs from a single request using Pino's child logger:

app.addHook('onRequest', async (request) => {
  request.traceId = request.headers['x-trace-id'] || crypto.randomUUID()
  request.log = request.log.child({ traceId: request.traceId })
})

In LogFlow, click View trace to see the entire request flow grouped by traceId.

Verify

Restart your app and make a request. Open LogFlow → Live Tail — logs appear within a few seconds.

FAQ

Does this affect Pino's performance? The stream writes are synchronous from Pino's side. The actual HTTP requests to LogFlow happen asynchronously in the background, so there's no blocking.

What if LogFlow is down? Logs are queued in memory and retried automatically. If the queue fills up (default 1000 logs), the oldest are dropped.

Pino levels vs LogFlow levels Pino numeric levels map to LogFlow as follows: 10 (trace) → trace, 20 → debug, 30 → info, 40 → warn, 50 → error, 60 → fatal.

Pino Logging Integration