Email Verification Service with Fiber

A clean architecture based email verification service that generates and validates verification codes.

Features

• Clean Architecture implementation
• In-memory verification code storage
• SMTP email service integration
• Code generation and hashing
• Configurable code expiration
• Thread-safe operations

Project Structure

email-verification/
├── api/
│   └── handlers/         # HTTP handlers
├── application/          # Application business logic
├── domain/              # Domain models and interfaces
├── infrastructure/      # External implementations
│   ├── code/           # Code generation
│   ├── email/          # SMTP service
│   └── repository/     # Data storage
└── config/             # Configuration

Configuration

The application is configured via environment variables. Copy .env.example to .env and fill in your SMTP credentials:

cp .env.example .env

Variable	Required	Default	Description
SMTP_HOST	No	smtp.gmail.com	SMTP server hostname
SMTP_PORT	No	587	SMTP server port
SMTP_USER	Yes	—	SMTP username / email address
SMTP_PASS	Yes	—	SMTP password or app-password

The application exits with a fatal error on startup if SMTP_USER or SMTP_PASS are not set.

API Endpoints

Method	URL	Description
POST	/verify/send/:email	Send verification code
POST	/verify/check/:email/:code	Verify the received code

Example Usage

1. Send verification code:

curl -X POST http://localhost:3000/verify/send/[email protected]

2. Verify code:

curl -X POST http://localhost:3000/verify/check/[email protected]/123456

Response Examples

Success:

{
    "message": "Code verified successfully"
}

Error:

{
    "error": "invalid code"
}

How to Run

1. Copy .env.example to .env and set your SMTP credentials.
2. Export the environment variables and run the application:

export $(cat .env | xargs)
go run main.go

Dependencies

• Fiber v3
• Go 1.23+