A minimal, flexible logging library for Node.js, built on top of winston. Supports ESM, with TypeScript types included.
- Simple, consistent logging API for Node.js
- Built on winston
- Supports ESM
- Default and named exports for maximum flexibility
- TypeScript type definitions included
- Supports structured JSON output with optional timestamps
- Supports child loggers with persistent context
- Serializes Error objects with name, message, and stack
- Supports configurable metadata redaction
- Supports logging primitives and arrays as meta:
log.info('msg', 42)logs{ value: 42 }log.info('msg', [1,2,3])logs{ value: [1,2,3] }
- Node.js 26 or newer
npm install @eliware/log// Example usage for ESMimportlog,{logasnamedLog,createLogger}from'@eliware/log';log.info('Hello from example.mjs (default import)',{foo: 'bar'});log.info('Primitive value',42);// primitive valuelog.info('Array value',[1,2,3]);// array valuenamedLog.info('Hello from example.mjs (named import)',{foo: 'bar'});namedLog.info('Primitive value','test');// primitive valueconstcustomLogger=createLogger({level: 'debug'});customLogger.debug('Custom logger debug message',{custom: true});customLogger.debug('Primitive debug',true);// primitive valueA pre-configured logger instance. Available as both the default and a named export (log).
.info(message, meta?).debug(message, meta?).warn(message, meta?).error(message, meta?)- ...and all other winston logger methods.
Meta argument:
- If you pass a primitive or array as the second argument, it will be logged as
{ value: ... }. - If you pass an object, it will be logged as usual.
Creates a new winston logger instance.
Options:
level(string): Log level (default:process.env.LOG_LEVELor'info')transports(array): Array of winston transports (default: Console)format(textorjson): Output format (default:text)timestamp(boolean): Include timestamps in JSON output (default:false)redactKeys(string[]): Metadata keys to redact, case-insensitively
Returns:winston.Logger
Type definitions are included:
exportdeclarefunctioncreateLogger(options?: {level?: string;transports?: import('winston').Transport[];format?: 'text'|'json';timestamp?: boolean;redactKeys?: string[];}): import('winston').Logger&{debug(message: string,meta?: unknown): void;info(message: string,meta?: unknown): void;warn(message: string,meta?: unknown): void;error(message: string,meta?: unknown): void;};exportdeclareconstlog: import('winston').Logger&{debug(message: string,meta?: unknown): void;info(message: string,meta?: unknown): void;warn(message: string,meta?: unknown): void;error(message: string,meta?: unknown): void;};exportdefaultlog;Use redactKeys for sensitive metadata. Objects are shallowly summarized; nested object contents are not recursively serialized. Error fields are also subject to redaction. JSON output includes timestamps only when timestamp: true; text output safely summarizes objects and serializes BigInt values. Configure transports explicitly for tests and alternate destinations.
npm test
npm run test:gaps
npm run lint
npm run typecheck
npm run packDo not log secrets or sensitive payloads. Configure redactKeys for credential-bearing metadata and review custom transports before enabling them.
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