RecaptchaV2Provider

Package: @nauth-toolkit/recaptcha Type: Provider Class

Checkbox-based reCAPTCHA provider requiring explicit user interaction.

NestJS

import { RecaptchaV2Provider } from '@nauth-toolkit/recaptcha';

Express

import { RecaptchaV2Provider } from '@nauth-toolkit/recaptcha';

Fastify

import { RecaptchaV2Provider } from '@nauth-toolkit/recaptcha';

Constructor

new RecaptchaV2Provider(config: RecaptchaV2Config)

RecaptchaV2Config

Property	Type	Required	Description
secretKey	string	Yes	Secret key from Google reCAPTCHA admin console.
timeout	number	No	Request timeout in milliseconds. Default: 10000.

Methods

verify()

Verify reCAPTCHA v2 token with Google's API.

async verify(token: string, remoteIp?: string): Promise<RecaptchaVerificationResult>

Parameters

• token - reCAPTCHA token from client
• remoteIp - Client IP address (optional, recommended)

Returns

• RecaptchaVerificationResult - Verification result with success status

validateConfig()

Validate provider credentials at startup by sending a probe request to Google's API.

async validateConfig(): Promise<RecaptchaValidationResult>

Returns

• RecaptchaValidationResult - { valid, message, hint?, httpStatus? }

Called automatically during NAuth.create() when validateOnStartup is 'warn' (default) or 'error'. Detects invalid secret keys before a real user hits the endpoint.

Example

NestJS

import { NAuthModule } from '@nauth-toolkit/nestjs';
import { RecaptchaV2Provider } from '@nauth-toolkit/recaptcha';

@Module({
  imports: [
    NAuthModule.forRoot({
      recaptcha: {
        enabled: true,
        provider: new RecaptchaV2Provider({
          secretKey: process.env.RECAPTCHA_V2_SECRET_KEY!,
        }),
      },
    }),
  ],
})
export class AppModule {}

Express

import { NAuth } from '@nauth-toolkit/core';
import { ExpressAdapter } from '@nauth-toolkit/express';
import { RecaptchaV2Provider } from '@nauth-toolkit/recaptcha';

const nauth = await NAuth.create({
  config: {
    recaptcha: {
      enabled: true,
      provider: new RecaptchaV2Provider({
        secretKey: process.env.RECAPTCHA_V2_SECRET_KEY!,
      }),
    },
  },
  dataSource,
  adapter: new ExpressAdapter(),
});

Fastify

import { NAuth } from '@nauth-toolkit/core';
import { FastifyAdapter } from '@nauth-toolkit/fastify';
import { RecaptchaV2Provider } from '@nauth-toolkit/recaptcha';

const nauth = await NAuth.create({
  config: {
    recaptcha: {
      enabled: true,
      provider: new RecaptchaV2Provider({
        secretKey: process.env.RECAPTCHA_V2_SECRET_KEY!,
      }),
    },
  },
  dataSource,
  adapter: new FastifyAdapter(),
});

When to Use

• Acceptable user friction (checkbox interaction)
• Simple bot protection without scoring
• Lower setup complexity than v3/Enterprise

Setup

1. Go to Google reCAPTCHA Admin Console
2. Create a new site with reCAPTCHA v2 checkbox
3. Add your domains (including localhost for development)
4. Copy the secret key for backend configuration
5. Copy the site key for frontend integration

Related

• RecaptchaConfig - Configuration interface
• RecaptchaV3Provider - Score-based alternative
• reCAPTCHA Guide - Complete implementation guide