otplib API Documentation / @otplib/hotp / generateSync

Function: generateSync()

generateSync(options): string

Defined in: hotp/src/index.ts:155

Generate an HMAC-based One-Time Password (HOTP) synchronously

This is the synchronous version of generate. It requires a crypto plugin that supports synchronous HMAC operations (e.g., NodeCryptoPlugin or NobleCryptoPlugin). Using this with WebCryptoPlugin will throw an error.

Parameters

options

HOTPGenerateOptions

HOTP generation options

Returns

string

The HOTP code as a string

See

• generate for the async version
• RFC 4226 Section 5.3

Throws

If the algorithm is invalid or unsupported by the plugin

Throws

If HMAC computation fails or the plugin does not support sync operations

Example

import { generateSync } from '@otplib/hotp';
import { NodeCryptoPlugin } from '@otplib/plugin-crypto-node';

const hotp = generateSync({
  secret: new Uint8Array([1, 2, 3, 4, 5]),
  counter: 0,
  digits: 6,
  crypto: new NodeCryptoPlugin(),
});
// Returns: '123456'