Notification API Center

A robust API written in go, designed to centralize push notification management

Features

• Security: JWT Auth.
• Scalability: Rate Limiting.
• Web push: Subscription and bulk notification send.
• Modularity: Clear responsability separation between domains (Applications, Auth, Users, Notifications).

Instalation and configuration

git clone https://github.com/Angel-del-dev/push-notification-center.git push-notification-center
cd push-notification-center
go mod download
cp .env-example .env

--psql
|> insert into applications(name, description) values ('...', '...');
|> insert into applications_keys(application, password) values ('...', '...');

Structure and execution

Dependencies

• github.com/gofiber/fiber/v3: Go Web framework.
• github.com/jackc/pgx/v5: PostgreSQL driver.
• golang.org/x/crypto/bcrypt: Secure hash creation/validation.

Server startup

cd scripts
./runbuild.sh

Prerequisites

• Go (Versión 1.20+, preferably 1.25)
• PostgreSQL engine.

Environment variables (.env)

Project startup depends on .env variables.

Var	Description	Type	Required	Domain
DB_HOST	Database host.	string	true	DB
DB_NAME	Database name.	string	true	DB
DB_USER	Database username.	string	true	DB
DB_PASSWORD	Database password.	string	true	DB
DB_PORT	Database port.	int	true	DB
JWT_SECRET	Secret string to authenticate/create tokens(Random).	string	true	Auth
VAPIDPRIVATEKEY	Push notification private key.	string	true	Notifications
VAPIDPUBLICKEY	Push notification private key.	string	true	Notifications

Note: VAPID KEYS can be generated using /internal/domains/notifications/service.go:GenerateVAPIDKeys()

API Endpoints

1. Authentication (/auth)

Endpoint:

Obtains a JWT token

• Method: POST
• Endpoint: /auth
• Middleware: ContentTypeAllowed("application/json")
• Request body:

  {
      "application": "...", 
      "key": "...", 
      "password": "..."
  }

• Response (200 OK): Returns auth token and expiration date

  {
      "access_token": "...", 
      "expires_at": "...", 
      "expires_in": 900 
  }

2. User administration (/users)

Endpoint: Store (Create user)

Creates a new user and links it to an application, Required for sending notifications.

• Method: POST
• Route: /users
• Middleware: JWT Middleware (SecretJWT) y Content Type JSON.
• Request body:

  {
      "user": "..."
  }

• Response (200 OK): {} (Success)
• Errors:
  • 409 Conflict: User already exists for the application.
  • 401 Unauthorized: Expired or invalid JWT Token.

Endpoint: Remove

Unlinks and removes a user from an application.

• Method: DELETE
• Route: /users
• Middleware: JWT Middleware (SecretJWT) y Content Type JSON.
• Request body:

  {
      "user": "..."
  }

• Response (200 OK): {} (Success)
• Errors:
  • 404 Not Found: User not found.

3. Web Push Notifications (/notifications)

Endpoint: Device subscribe

Saves a devices subscription and links it to a user

• Method: POST
• Route: /notifications/subscribe
• Middleware: JWT Middleware, Content Type JSON.
• Request body:

  {
      "user": "...", 
      "endpoint": "...",       // Provided by browser
      "p256dh": "...",         // Provided by browser
      "tag": "..."             // *Optional*, useful to send notifications when a user has multiple devices
  }

• Response (200 OK): { "message": "Subscription saved" }
• Errors:
  • 400 Bad Request: Invalid or insufficient parameters.
  • 409 Conflict: The device is already subscribed.

Endpoint: Send

Sends a notification to one or more devices from a user, can filter by tag.

• Method: POST
• Route: /notifications/send
• Middleware: JWT Middleware, Content Type JSON.
• Request body:

  {
      "user": "...", 
      "title": "...", 
      "message": "...", 
      "icon": "...url...", 
      "tag": "..." // *Optional*
  }

• Response (200 OK): {}.
• Response partial (202 Accepted):
  • Couldn't send notification to some devices and those devices subscriptions have been removed.
• Errors:
  • 401 Unauthorized
  • 400 Bad Request: User data, tittle or message invalid/missing.
  • 500 Internal Server Error