OTPX

A lightweight, flexible OTP (One-Time Password) generator for Node.js and TypeScript.

Supports multiple charsets (numeric, alphabetic, alphanumeric, hex, or custom), case options, and exclusion of ambiguous characters like O0Il.

Features

• Generate OTPs with customizable length
• Built-in charsets: numeric, alphabetic, alphanumeric, hex
• Provide your own custom charset
• Exclude visually similar characters (O, 0, I, l)
• Case handling: upper, lower, or mixed
• Secure random generation using Node.js crypto

Installation

npm install otpx
# or

Usage

Basic Example

import OTPX from "otpx";

// Generate a 6-digit numeric OTP
const otp = OTPX.numeric();
console.log(otp); // e.g. "583920"

Using Different Charsets

import OTPX from "otpx";

// Alphabetic OTP (mixed case)
console.log(OTPX.alphabetic(8)); // e.g. "aZkPqTrB"

// Alphanumeric OTP with options
console.log(OTPX.alphanumeric(10, { excludeSimilar: true }));
// e.g. "9kPz3Hd2Gq"

// Hexadecimal OTP
console.log(OTPX.hex(12)); // e.g. "a3f92b8e10d7"

Custom Charset

import OTPX from "otpx";

// Only vowels
const otp = OTPX.generateOtp(6, { custom: "aeiou" });
console.log(otp); // e.g. "uaeioe"

Case Options

import OTPX from "otpx";

console.log(OTPX.alphabetic(6, { case: "upper" })); // "QTRPZB"
console.log(OTPX.alphabetic(6, { case: "lower" })); // "xndqem"
console.log(OTPX.alphabetic(6, { case: "mixed" })); // "xNdQeM"

API Reference

OTPX.generateOtp(length?, charset?, options?)

• length (default 6) → Number of characters

• charset → "numeric" | "alphabetic" | "alphanumeric" | "hex" | { custom: string }

• options:

  • excludeSimilar?: boolean → Excludes confusing chars (O0Il)
  • case?: "upper" | "lower" | "mixed" → Controls casing
  • run?: () => void → Optional callback invoked once after OTP is generated. Useful for logging, hooks, or side effects.

Shorthand Methods

• OTPX.numeric(length?)
• OTPX.alphabetic(length?, options?)
• OTPX.alphanumeric(length?, options?)
• OTPX.hex(length?)

Using the run Option

You can pass a run callback to generateOtp to perform actions after the OTP is generated (e.g., logging, hooks, analytics):

import OTPX from "otpx";

OTPX.generateOtp(6, "numeric", {
  run: () => {
    console.log("OTP was generated!");
  }
});

Example with NestJS

import { Injectable } from "@nestjs/common";
import OTPX from "otpx";

@Injectable()
export class OtpService {
  generateLoginOtp() {
    return OTPX.numeric(6);
  }
}

License

MIT