Core Concepts

Master the fundamental building blocks of Vestig logging.

Overview

Vestig is built around a few core concepts that make logging both powerful and intuitive:

• Structured Logging — JSON-based log entries with rich metadata
• Log Levels — Fine-grained control over what gets logged
• Child Loggers — Namespaced loggers for organized output

Quick Start

1import { log } from 'vestig'
2 
3// Simple logging
4log.info('Application started')
5log.error('Something went wrong', { error: new Error('Oops') })
6 
7// Create a namespaced child logger
8const dbLog = log.child('database')
9dbLog.debug('Query executed', { sql: 'SELECT * FROM users' })

Core Topics

Logging Basics

Learn how to create loggers and structure your log output effectively.

• Creating loggers with createLogger()
• Using the default log instance
• Adding metadata to log entries
• Understanding log entry structure

→ Logging Basics

Log Levels

Understand the log level hierarchy and when to use each level.

• Level hierarchy: trace → debug → info → warn → error
• Setting minimum log levels
• Level-based filtering
• Environment-specific configurations

→ Log Levels

Structured Output

Configure how your logs are formatted and displayed.

• JSON vs human-readable output
• Custom formatters
• Console styling and colors
• Production vs development formats

→ Structured Output

Child Loggers

Create scoped loggers with namespaces and inherited context.

• Creating child loggers with log.child()
• Namespace hierarchies
• Context inheritance
• When to use child loggers

→ Child Loggers

Next Steps

• Tracing — Add distributed tracing with spans
• Transports — Send logs to different destinations
• Sampling — Control log volume in production