clarity

A modern debug client for TypeScript, offering powerful logging capabilities with colored output, performance tracking, log rotation, and both CLI & library support.

Features

• 🚀 High-Performance Logging
• 🎯 Domain-Specific Namespaces
• 🤞 Fingers-Crossed Log Buffering
• 🔄 Automatic Log Rotation & Cleanup
• 🔐 Encrypted Log Storage

Output & Formatting

• 🎨 Rich Color-Coded Console Output
• 📊 Multiple Log Levels (debug, info, success, warn, error)
• 🔠 Format String Support (%s, %d, %j, etc.)
• ⚡ Built-in Performance Tracking

Platform Support

• 🌐 Universal (Browser + Server)
• 🛠️ CLI & Library APIs
• 💻 First-Class TypeScript Support
• 📦 Zero External Dependencies

Install

bun install clarity
npm install clarity

Get Started

There are two ways of using clarity: as a library or as a CLI.

Library

Given the npm package is installed:

import { Logger } from 'clarity'

// Configure the logger
const logger = new Logger('parser', {
  // Optional configuration
  maxLogSize: 5 * 1024 * 1024, // 5MB

  rotation: {
    maxLogFiles: 10,
    compress: true,
  },

  encrypted: true,
})

// Basic logging
logger.info('Starting parser...')
logger.success('Document parsed successfully')
logger.warning('Legacy format detected')
logger.error('Failed to parse document')

// Performance tracking
const end = logger.info('Starting expensive operation...')
// ... do work ...
end('Operation completed') // automatically includes time taken

// Domain-specific logging
const parseLogger = logger.extend('json')
parseLogger.info('Parsing JSON...') // outputs with [parser:json] prefix

// Debug mode
logger.debug('Additional debug information')

// Format string support
logger.info('Found %d errors in %s', 3, 'document.txt')

// Conditional execution
logger.only(() => {
  // Only runs when logging is enabled
  logger.info('Additional diagnostics...')
})

To learn more about the Library usage, please refer to the Library documentation.

CLI

# Watch logs in real-time
clarity watch --level debug --name "parser:*"
clarity watch --json --timestamp

# Log a one-off message
clarity log "Starting deployment" --level info --name "deploy"

# Export logs to a file
clarity export --format json --output logs.json --level error
clarity export --start 2024-01-01 --end 2024-01-31

# Show and follow last N lines
clarity tail --lines 50 --level error --follow
clarity tail --name "api:*"

# Search through logs
clarity search "error connecting to database" --level error
clarity search "deployment" --start 2024-01-01 --case-sensitive

# Clear log history
clarity clear --level debug --before 2024-01-01
clarity clear --name "temp:*"

# Configure log rotation
clarity config set --key maxLogSize --value 5242880  # 5MB
clarity config set --key maxLogFiles --value 10
clarity config set --key compressLogs --value true

# Other configuration
clarity config set --level debug
clarity config list

# Utility commands
clarity --help    # Show help information
clarity --version # Show version number

All commands support the following common options:

• --level: Filter by log level (debug, info, warning, error)
• --name: Filter by logger name (supports patterns like "parser:*")
• --verbose: Enable verbose output

Command Reference

• watch: Monitor logs in real-time with filtering and formatting options
• log: Send one-off log messages with specified level and name
• export: Save logs to a file in various formats with date range filtering
• tail: Show and optionally follow the last N lines of logs
• search: Search through logs using patterns with date range and case sensitivity options
• clear: Clear log history with level, name, and date filtering
• config: Manage clarity configuration (get, set, list)

To learn more about the CLI usage, please refer to the CLI documentation.

Configuration

Clarity can be configured programmatically, using environment variables, or through the CLI:

Programmatic Configuration

import { Logger } from 'clarity'

const logger = new Logger('app', {
  // Log Levels
  level: 'debug',
  defaultName: 'app',
  verbose: true,

  // Output Format
  format: 'json',
  timestamp: true,
  colors: true,

  // Log Rotation
  rotation: {
    frequency: 'daily',
    maxLogSize: 10 * 1024 * 1024, // 10MB
    maxLogFiles: 5,
    compress: true,
  },

  encrypt: true,
  logDirectory: '~/.clarity/logs',
})

Environment Variables

# Enable logging
DEBUG=true
DEBUG=parser # enable specific logger
DEBUG=parser:* # enable logger and all subdomains

# Control log level
LOG_LEVEL=debug # show all logs
LOG_LEVEL=error # show only errors

CLI Configuration

# Configure logging
clarity config set --key level --value debug
clarity config set --key maxLogSize --value 5242880 # 5MB

Testing

bun test

Changelog

Please see our releases page for more information on what has changed recently.

Contributing

Please see CONTRIBUTING for details.

Community

For help, discussion about best practices, or any other conversation that would benefit from being searchable:

Discussions on GitHub

For casual chit-chat with others using this package:

Join the Stacks Discord Server

Postcardware

You will always be free to use any of the Stacks OSS software. We would also love to see which parts of the world Stacks ends up in. Receiving postcards makes us happy—and we will publish them on our website.

Our address: Stacks.js, 12665 Village Ln #2306, Playa Vista, CA 90094, United States 🌎

Sponsors

We would like to extend our thanks to the following sponsors for funding Stacks development. If you are interested in becoming a sponsor, please reach out to us.

• JetBrains
• The Solana Foundation

Credits

• debug
• @open-draft/logger
• Chris Breuer
• All Contributors

License

The MIT License (MIT). Please see LICENSE for more information.

Made with 💙