loglayer

NPM Downloads

loglayer is a unified logger that routes logs to various logging libraries, cloud providers, files, and OpenTelemetry while providing a fluent API for specifying log messages, metadata and errors.

For full documentation, read the docs.
Older 4.x documentation

// Example using the Pino logging library with LogLayer
import { LogLayer } from 'loglayer';
import { pino } from 'pino';
import { PinoTransport } from '@loglayer/transport-pino';
import { redactionPlugin } from '@loglayer/plugin-redaction';

const log = new LogLayer({
  // Multiple loggers can also be used at the same time. 
  // Need to also ship to a cloud provider like DataDog at the same time? You can!
  transport: new PinoTransport({
    logger: pino()
  }),
  // Plugins can be created to modify log data before it's shipped to your logging library.
  plugins: [
    redactionPlugin({
      paths: ['password'],
      censor: '[REDACTED]',
    }),
  ],
})

log.withPrefix("[my-app]")
  .withMetadata({ some: 'data', password: 'my-pass' })
  .withError(new Error('test'))
  .info('my message')

{
  "level":30,
  "time":1735857465669,
  "pid":30863,
  "msg":"[my-app] my message",
  // The placement of these fields are also configurable!
  "password":"[REDACTED]",
  "some":"data",
  "err":{
    "type":"Error",
    "message":"test",
    "stack":"Error: test\n ..."
  }
}

Installation

Install the core package:

npm i loglayer

Quick Start

import { LogLayer, ConsoleTransport } from 'loglayer'

const log = new LogLayer({
  transport: new ConsoleTransport({
    logger: console,
  }),
})

log
  .withMetadata({ some: 'data'})
  .withError(new Error('test'))
  .info('my message')