CommonFunLib

CommonFunLib is a small Node utility package for everyday helpers: number and string checks, random data generation, unit conversion, hashing, Base64, and HMAC signing.

It can also run the same utilities as an Express API.

Version 1.0.1

This release expands the computing toolkit with Fibonacci, average, median, title case, word count, Nano IDs, API keys, MAC addresses, semver strings, timestamps, number-base conversion, duration conversion, timestamp conversion, color conversion, SHA3 hashing, Base64URL helpers, HMAC SHA512, and checksums.

Install

npm install commonfunlib

Use As A Package

import {
  isEven,
  fibonacci,
  slugify,
  generateApiKey,
  convertNumberBase,
  sha3_256,
} from "commonfunlib";

console.log(isEven(42));
console.log(fibonacci(8));
console.log(slugify("My New Tool"));
console.log(generateApiKey("cfl", 24));
console.log(convertNumberBase("255", 10, 16));
console.log(sha3_256("CommonFunLib"));

Grouped helpers are also available:

import { common, generate, convert, hash } from "commonfunlib";

common.isPrime(17);
generate.nanoid(21);
convert.timestamp("2026-06-28T12:00:00.000Z", "iso", "seconds");
hash.base64UrlEncode("hello world");

If you prefer classes:

const { Converter, Generator, Hashing, CommonFunctions } = require("commonfunlib");

const converter = new Converter();
const generator = new Generator();

converter.convertWeight(5, "kg", "lb");
generator.generateApiKey("cfl", 24);
Hashing.hmacSha512("payload", "secret");
CommonFunctions.average("4,8,15,16,23,42");

Run The API Server

From this package folder:

npm start

After publishing, consumers can also run:

npx commonfunlib-api

The API listens on PORT or 3001 by default.

Currency Conversion

Currency conversion uses FREECURRENCYAPI_KEY from the environment.

FREECURRENCYAPI_KEY=your-key npm start

For direct package use:

const { fetchExchangeRates, convertCurrency } = require("commonfunlib");

await fetchExchangeRates();
console.log(convertCurrency(100, "USD", "EUR"));