async-config

async-config

Load nestjs-xotp options from environment variables with XOTPModule.forRootAsync().

This example shows:

• An OtpConfigService that implements XOTPOptionsFactory
• XOTPModule.forRootAsync({ imports, useExisting }) wiring
• Reading TOTP settings from process.env at bootstrap

Run

From the repository root:

npm run build
cd examples/async-config
npm install
npm run start

For local development:

npm run start:dev

The app listens on http://localhost:3001 by default (PORT overrides).

Custom options

OTP_ISSUER=Acme \
OTP_TOTP_DIGITS=8 \
OTP_TOTP_DURATION=30 \
OTP_TOTP_WINDOW=1 \
OTP_TOTP_ALGORITHM=sha1 \
npm run start

Variable	Default	Description
OTP_ISSUER	MyApp	Issuer label for key URIs
OTP_TOTP_ALGORITHM	sha1	TOTP hash algorithm
OTP_TOTP_DIGITS	6	Token length
OTP_TOTP_DURATION	30	Step size in seconds
OTP_TOTP_WINDOW	1	Validation drift window
PORT	3001	HTTP port

Try it

Check the loaded settings:

curl -s http://localhost:3001/otp/settings

Response:

{
  "issuer": "MyApp",
  "algorithm": "sha1",
  "digits": 6,
  "duration": 30,
  "window": 1
}

Verify a token (use a secret from an authenticator app or from 2fa-basic):

curl -s -X POST http://localhost:3001/otp/verify \
  -H 'content-type: application/json' \
  -d '{"secret":"JBSWY3DPEHPK3PXP","token":"123456"}'

Response:

{ "valid": false }

Endpoints

Method	Path	Description
GET	/otp/settings	Show effective TOTP options loaded from config
POST	/otp/verify	Validate a token against a base32 secret

How it works

OtpModule imports XOTPModule.forRootAsync() and delegates option creation to OtpConfigService:

XOTPModule.forRootAsync({
  imports: [OtpConfigModule],
  useExisting: OtpConfigService,
})

OtpConfigService.createXOTPModuleOptions() maps environment variables to XOTPModuleOptions. In a real app, this service might read from @nestjs/config, a secrets manager, or another config source instead of process.env directly.