Powerful logger for Node.js

Usage no npm install needed!

<script type="module">
  import logtopus from 'https://cdn.skypack.dev/logtopus';



Build Status

Logtopus is a powerful logger for Node.js with different transports

Logtopus Logger

Built in logger:

Additional logger:


const log = require('logtopus').getLogger('mylogger');

log.warn('My beer is nearly finish!');

Log levels

debug    development  Logs debugging informations
info     development  Helpful during development
res      staging      Logs requests
req      staging      Logs responses
sys      production   Logs application states
warn     production   Logs warnings
error    production   Logs errors

For example, setting log level to req includes these log levels: req, sys, warn, error Setting log level to debug means all log levels are activated log level error logs errors only.


log.setLevel('res');        // To be ignored in this log level
log.debug('Log example:');  // To be ignored in this log level
log.info('This would not be logged');
log.res('POST /account');
log.req('200 OK');
log.sys('Request done!');
log.warn('Request was unauthorized!');
log.error('An error has been occurred!');

// prints

res: POST /account
req: 200 OK
sys: Request done!
warn: Request was unauthorized!
error: An error has been occurred!

Express logger

Logtopus comes with a logger for Express/Connect.

logtopus.express() returns a middleware for Express/Connect. It acepts an optional options object

let express = require('express');
let logtopus = require('../logtopus');

let app = express();

  logLevel: 'debug'


logLevel Sets current log level

Koa logger

Logtopus also supports Koa

logtopus.koa() returns a middleware for Koa. It acepts an optional options object

let koa = require('koa');
let logtopus = require('../logtopus');

let app = koa();

  logLevel: 'debug'


logLevel Sets current log level

Adding custom loggers

Logtopus was designed as an extensible logger. You can add a custom logger by creating a logger class and load it into logtopus. The example below shows a minimal logger class.

class LogtopusLogger {
  constructor(conf) {
    // conf contains the logger conf

  log(logmsg) {
    const date = logmsg.time.toISOString()
    console.log(`[${date}] ${logmsg.msg}`)

module.exports = LogtopusLogger

The logger class requires a log method. It takes one argument which contains a log object. The first argument of a log call is the log message, all other arguments are log data.

logmsg: {
  type: 'info', // The logtype eg: debug, info, error, sys
  msg: 'Log message string', // Log message, but without CLI color codes
  cmsg: 'Colorized log message', // Log message with CLI color codes
  time: new Date(), // Current date
  uptime: process.uptime(), // Process uptime in ms
  data: [] // All other arguments as an array

Now, the class has to be load into logtopus. You can do it by using the .addLogger() method if your logger is a priveate logger. Otherwis publish it on npm by using our logger name conventions. logtopus-${loggername}-logger Add a new config block into the logtopus config by using loggername as namespace and logtopus tries to load the logger.

const log = logtopus.getLogger('mylogger')
log.addLogger('loggerName', loggerClass)