IPreSignupHookProvider

Hook interface for executing validation before user creation.

Overview

The IPreSignupHookProvider interface enables validation and blocking of signups before user creation. This is the only blocking hook - it can throw exceptions to prevent signup.

The hook is blocking - throwing an exception prevents user creation.

Interface

interface IPreSignupHookProvider {
  execute(
    data: PreSignupHookData,
    signupType: 'password' | 'social',
    provider?: string,
    adminSignup?: boolean,
  ): Promise<void>;
}

Parameters

Parameter	Type	Description
data	PreSignupHookData	Signup DTO or OAuth profile
signupType	'password' | 'social'	Type of signup
provider	string	Social provider name (social signups only)
adminSignup	boolean	Whether admin-initiated signup

When Hook Fires

• Before password signup via signup()
• Before social signup (web redirect or native mobile flows)
• Before admin signup via adminSignup() or adminSignupSocial()

Blocking Signup

Throw NAuthException with AuthErrorCode.PRESIGNUP_FAILED:

throw new NAuthException(AuthErrorCode.PRESIGNUP_FAILED, 'Email domain not allowed');

Example

import { IPreSignupHookProvider, NAuthException, AuthErrorCode } from '@nauth-toolkit/core';

export class DomainValidationHook implements IPreSignupHookProvider {
  async execute(data, signupType) {
    const domain = data.email?.split('@')[1];
    const allowedDomains = ['company.com'];

    if (domain && !allowedDomains.includes(domain)) {
      throw new NAuthException(AuthErrorCode.PRESIGNUP_FAILED, 'Domain not allowed');
    }
  }
}

Related

• HookRegistryService - Hook registration
• @PreSignupHook() - NestJS decorator
• NAuthException - Exception handling
• Lifecycle Hooks Guide - Complete hooks overview