@alcyone-labs/simple-logger

A lightweight, flexible, and type-safe logging library for TypeScript applications.

Features

• Transports: Plug-and-play transports (Console, File, Remote, etc.)
• Scoped Logging: Create scoped loggers with persistent contextual metadata.
• Type-Safe: Built with Zod for robust data validation and generic support.
• Extensible: Easy to add custom transports.

Installation

pnpm add @alcyone-labs/simple-logger

Quick Start

import { useLogging } from "@alcyone-labs/simple-logger";

const logger = useLogging();

logger.info({
  message: "Hello world!",
  data: {
    metadata: { env: "production" },
    foo: "bar",
  },
});

Scoped Logging

Scoped loggers allow you to attach metadata to every log message generated by that logger instance. This is particularly useful for tracking requests or service-specific logs.

import { useLogging } from "@alcyone-labs/simple-logger";

// Create a logger for a specific service
const serviceLogger = useLogging({ service: "auth-api" });

function handleRequest(userId: string) {
  // Create a sub-logger for a specific request
  const logger = useLogging({ userId });

  logger.info({
    message: "User login attempt",
    data: {
      metadata: { method: "oauth" },
    },
  });
}

Custom Transports

You can easily implement your own transports by matching the ITransport interface.

import {
  addTransport,
  ConsoleTransport,
  RemoteTransport,
  type ITransport,
  type TLog,
} from "@alcyone-labs/simple-logger";

// Add a remote logger
addTransport(new RemoteTransport("https://logs.example.com", "error"));

// Add a console logger with debug level
addTransport(new ConsoleTransport("debug"));

// Or implement your own
class MyCustomTransport implements ITransport {
  constructor(public level = "info") {}
  info(data: TLog) {
    /* ... */
  }
  // ...
}

API Reference

useLogging(metadata?: Record<string, any>)

Returns a logger object with info, debug, warn, and error methods. Any metadata passed here will be merged into every log message.

configureLogger(options: { transports?: ITransport[] })

Resets the logger configuration with a new set of transports.

addTransport(transport: ITransport)

Adds a new transport to the existing list.

TLog

The type of the log message object, validated via Zod.

{
  message: string;
  data: {
    metadata?: Record<string, any>;
    [key: string]: any;
  }
}

License

MIT