Create a Complete User Authentication System with PostgreSQL & Webhooks

Generate Secure User Authentication with One Webhook

Streamline user onboarding and security for your applications using this n8n workflow. This template handles signup, login, and password resets through a single endpoint, making it ideal for developers building MVPs or scaling apps without a full authentication backend.

Who Is This For? This workflow is designed for:

Developers, indie hackers, and teams building web, mobile, or API-driven applications. Those who need a quick and secure authentication layer. Anyone tired of writing custom auth code or managing third-party services like Auth0 for simple needs.

This template integrates seamlessly into your n8n setup.

What Problem Does This Workflow Solve? Building authentication from scratch is time-consuming and complex:

User Management: Managing registration, credential verification, and password recovery can take weeks of development time. Security: Ensuring secure password hashing, case-insensitive email matching, and robust error handling adds significant complexity. Integration: Creating consistent APIs for apps (e.g., React Native, Next.js, Flutter) is challenging.

This workflow provides a battle-tested, webhook-based authentication system that is:

Database-agnostic (works with PostgreSQL/Supabase). Extensible—deploy once and integrate across all your apps.

What This Workflow Does The workflow handles authentication tasks through a single webhook endpoint, offering the following functionality:

Webhook Entry:

Listens for POST requests at /webhook/auth. Processes a simple JSON payload, routing actions via a "path" parameter (signup, signin, forgot).

Signup:

Inserts new users into your database. Uses bcrypt-hashed passwords (via pgcrypto). Returns user details in the response.

Login:

Queries for case-insensitive email matches. Verifies passwords securely. Returns user information on successful login.

Forgot Password:

Generates a random 8-character password. Updates the password hash in the database. Returns the new password (suitable for email delivery).

Routing & Validation:

Uses n8n Switch and IF nodes to securely handle paths and credentials.

Standardized Responses:

Outputs clean JSON with status, message, and data for easy frontend parsing.

Error Handling:

Gracefully manages invalid inputs, duplicate entries, or database errors.

No more boilerplate—get authentication up and running in minutes!

Setup Instructions Follow these steps to set up the workflow:

Connect Your Accounts:

Use PostgreSQL or Supabase for user storage (free tiers are sufficient). Enable the following PostgreSQL extensions: uuid-ossp and pgcrypto.

Create the Users Table:

sqlCREATE TABLE users ( id uuid PRIMARY KEY DEFAULT uuid_generate_v4(), full_name text NOT NULL, email text UNIQUE NOT NULL, password_hash text NOT NULL, created_at timestamptz DEFAULT now() );

Configure Credentials :

Add PostgreSQL credentials to the n8n nodes ("Signup", "Login", "Reset Password"). Import the JSON workflow into n8n. Activate the workflow.

Test the Workflow:

Use Postman or curl to send requests to the auto-generated webhook URL.

How to Customize This Workflow

Extend the workflow to fit your specific needs with these modifications:

Add JWT Sessions:

Insert a node after successful login to generate and sign JWT tokens (e.g., using the Crypto node).

Email Integration:

Add a SendGrid or Mailgun node to the "Forgot Password" flow to automatically send new credentials.

Rate Limiting:

Include an HTTP Request node to check usage quotas before processing requests.

Multi-Database Support:

Replace PostgreSQL with MySQL or MongoDB by updating the query nodes.

Frontend Enhancements:

Extend JSON responses to include user avatars or roles by joining additional tables in SQL queries.

Triggers:

Add a Schedule node for batch user imports. Include a webhook for external authentication calls.