Environment Configuration

The logger auto-configures based on your environment.

Auto-Detection

The logger reads NODE_ENV and applies these defaults:

Setting	Development	Test	Production
minLevel	trace	trace	info
pretty	✅	✅	❌ (JSON)
colors	✅	✅	❌
redact	❌	❌	✅

Development Mode

When NODE_ENV !== 'production':

• All logs visible — trace through fatal
• Pretty output — human-readable, colorful
• No redaction — see full data for debugging

10:30:00 DEBUG [App] User login { password: 'secret123' }

Production Mode

When NODE_ENV === 'production':

• Info and above — trace/debug filtered out
• JSON output — for log aggregators (Datadog, Splunk, etc.)
• Redaction enabled — sensitive data protected

{"timestamp":"...","level":"info","message":"User login","data":{"password":"[REDACTED]"}}

Override Environment

Force Environment Mode

// Force production mode (even in development)
const log = createLogger('App', { env: 'production' });

// Force development mode (even in production)
const log = createLogger('App', { env: 'development' });

Override Individual Settings

// Production JSON + debug logs
const log = createLogger('App', {
  env: 'production',
  minLevel: 'debug',
});

// Development pretty + redaction enabled
const log = createLogger('App', {
  env: 'development',
  redact: true,
});

Conditional Configuration

const isProd = process.env.NODE_ENV === 'production';

const log = createLogger('App', {
  minLevel: isProd ? 'info' : 'trace',
  redact: isProd,
  pretty: !isProd,
});

Using env Option

const log = createLogger('App', {
  env: process.env.NODE_ENV as 'development' | 'test' | 'production',
});

Environment Variables

Variable	Description
NODE_ENV	'production' enables JSON output and redaction
LOG_LEVEL	Set minimum log level (trace … fatal)
LOG_ENABLED	'false' or '0' disables all logging
LOG_NAMESPACES	Comma-separated namespace patterns (api:*,auth:*)
NEXT_PUBLIC_LOG_LEVEL	Same as LOG_LEVEL when using Next.js client env
NEXT_PUBLIC_LOG_ENABLED / VITE_LOG_ENABLED	Same idea for enable/disable in browser bundles
VITE_LOG_LEVEL	Vite / client-side alias for LOG_LEVEL
DEBUG	'true' enables debug level in production
ENABLE_DEBUG_LOGS	Alternative to DEBUG
NO_COLOR	Disable colored output
FORCE_COLOR	Force colored output

Configure from Environment

configureFromEnv reads the table above. Pass getEnvVar in Node/Bun and anywhere getEnvVar can resolve names (it also consults import.meta.env when your bundler defines it):

import { configureFromEnv, getEnvVar } from '@nextrush/log';

configureFromEnv(getEnvVar);

For Deno explicitly:

import { configureFromEnv } from '@nextrush/log';

configureFromEnv((name) => Deno.env.get(name));

When NODE_ENV === 'test', configureFromEnv sets defaults.silent to true if you have not set it (quieter test runs).

Example .env Files

# .env.development
NODE_ENV=development
LOG_LEVEL=debug
LOG_ENABLED=true
LOG_NAMESPACES=*

# .env.production
NODE_ENV=production
LOG_LEVEL=info
LOG_ENABLED=true
LOG_NAMESPACES=api:*,auth:*,payments:*

# .env.test
NODE_ENV=test
LOG_ENABLED=false

Common Configurations

API Server (Production)

const log = createLogger('API', {
  env: 'production',
  minLevel: 'info',
  metadata: {
    service: 'user-api',
    version: process.env.npm_package_version,
  },
});

Debug Mode in Production

const log = createLogger('App', {
  env: 'production',
  minLevel: process.env.DEBUG === 'true' ? 'debug' : 'info',
});

CI/Test Environment

const log = createLogger('Test', {
  env: 'test',
  silent: process.env.CI === 'true', // Silent in CI
});