Implement OAuth2 Social Login

[Mkalbani]

Description

Allow users to sign in with Google, GitHub, Twitter.

Why This Matters

• Easier onboarding (no password to remember)
• Higher conversion rates
• Trusted identity verification

Providers to Support

• Google OAuth2
• GitHub OAuth2
• Twitter OAuth2 (optional)

Acceptance Criteria

• Add @nestjs/passport with OAuth strategies
• GET /api/v1/auth/google (redirect to Google)
• GET /api/v1/auth/google/callback (handle response)
• Link OAuth account to existing user (if email matches)
• Create new user if first-time OAuth login
• Store OAuth tokens securely
• Allow unlinking OAuth accounts

Database Schema

@Entity('oauth_accounts')
export class OAuthAccount {
  id: number;
  provider: 'google' | 'github' | 'twitter';
  providerId: string; // User ID from provider
  accessToken: string; // Encrypted
  refreshToken: string; // Encrypted
  user: User;
  createdAt: Date;
}

Environment Variables

GOOGLE_CLIENT_ID=...
GOOGLE_CLIENT_SECRET=...
GOOGLE_CALLBACK_URL=http://localhost:3000/api/v1/auth/google/callback

GITHUB_CLIENT_ID=...
GITHUB_CLIENT_SECRET=...
GITHUB_CALLBACK_URL=...

Resources

• NestJS Passport OAuth
• Google OAuth Setup
• GitHub OAuth Setup

Challenges

• Token storage security (encrypt!)
• Account linking (what if email already exists?)
• Token refresh logic

ETA: 6 hours

[Lynndabel]

Hello, I have carefully reviewed this issue description and acceptance criteria and will like to work on this please. ETA is 3hours. Please assign me this, thanks