@otplib/totp

RFC 6238 TOTP implementation for otplib.

Installation

``bash
npm install @otplib/totp
pnpm install @otplib/totp
yarn add @otplib/totp
`

Usage

`typescript
import { generate, verify } from "@otplib/totp";
import { crypto } from "@otplib/plugin-crypto-node";
import { base32 } from "@otplib/plugin-base32-scure";

// Generate a TOTP token
const token = await generate({
secret: "GEZDGNBVGY3TQOJQGEZDGNBVGY",
crypto,
base32,
});

// Verify a TOTP token
const result = await verify({
secret: "GEZDGNBVGY3TQOJQGEZDGNBVGY",
token: "123456",
crypto,
base32,
});

// result.valid: boolean
// result.delta: number | null
`

Functions

$3

Generate a TOTP code:

`typescript
import { generate } from '@otplib/totp';
import { crypto } from '@otplib/plugin-crypto-node';
import { base32 } from '@otplib/plugin-base32-scure';

const token = await generate({
secret: new Uint8Array([...]), // Required: secret as bytes
crypto, // Required: crypto plugin
base32, // Optional: base32 plugin (for decoding)
algorithm: 'sha1', // Optional: 'sha1' | 'sha256' | 'sha512'
digits: 6, // Optional: 6 | 7 | 8
period: 30, // Optional: time step in seconds
epoch: Math.floor(Date.now() / 1000), // Optional: current time in seconds
});
`

$3

Verify a TOTP code:

`typescript
import { verify } from '@otplib/totp';
import { crypto } from '@otplib/plugin-crypto-node';
import { base32 } from '@otplib/plugin-base32-scure';

const result = await verify({
secret: new Uint8Array([...]), // Required: secret as bytes
token: '123456', // Required: token to verify
crypto, // Required: crypto plugin
base32, // Optional: base32 plugin (for decoding)
algorithm: 'sha1', // Optional: hash algorithm
digits: 6, // Optional: expected digits
period: 30, // Optional: time step
epoch: Math.floor(Date.now() / 1000), // Optional: current time
epochTolerance: 30, // Optional: time tolerance in seconds
});

// Returns: { valid: boolean, delta: number | null }
`

$3

Get the remaining time before the next TOTP period:

`typescript
import { getRemainingTime } from "@otplib/totp";

const seconds = getRemainingTime(
Math.floor(Date.now() / 1000), // time
30, // period
0, // t0
);

// Returns: number of seconds remaining
`

$3

Get the time step used for a specific time:

`typescript
import { getTimeStepUsed } from "@otplib/totp";

const counter = getTimeStepUsed(
Math.floor(Date.now() / 1000), // time
30, // period
0, // t0
);

// Returns: the counter value
``

Documentation

Full documentation available at otplib.yeojz.dev:

- Getting Started Guide
- API Reference

License

MIT © 2026 Gerald Yeo