Backend API — Overview

The Backend API is the core of the Association App platform. It is built with Kotlin + Spring Boot and exposes a RESTful API consumed by the Admin UI, Mobile App, and WordPress Plugin.

Tech Stack

Layer	Technology	Version
Language	Kotlin	1.9.25
Framework	Spring Boot	3.5.6
Runtime	OpenJDK	21
Database	PostgreSQL	16
ORM	Spring Data JPA / Hibernate	—
Security	Spring Security + JWT (jjwt)	6.x / 0.13.0
API Docs	SpringDoc OpenAPI (Swagger)	2.8.13
Email	Spring Mail + Thymeleaf templates	—
Storage	Local / Google Cloud Storage / AWS S3	—
Push	Firebase Admin SDK (FCM)	9.2.0
Build	Gradle	8.5

Architecture

The API follows a multi-tenant architecture where each organisation is isolated. All data queries are automatically scoped to the authenticated user's organisation.

Admin UI  ──┐
Mobile App ──┼──► Spring Boot API ──► PostgreSQL
WP Plugin ──┘         │
                       ├──► SMTP (email)
                       ├──► FCM (push notifications)
                       └──► GCS / S3 (file storage)

Modules

Module	Description
Auth	JWT authentication, password reset, MFA, rate limiting
Users	Profiles, account status, email verification
Organizations	Multi-tenant org management, branding, settings
Roles & Permissions	RBAC with granular authority system
Members	Directory, invitations, join requests
Membership	Membership types, lifecycle, renewals
Events	Event creation, registration, waitlists
News	Articles, comments, scheduling
Documents	File storage with folder organisation
Notifications	Push notifications via FCM
Email	Templates, SMTP config, logs
Audit	Security event logging
Connectors	External system integrations (CRM, HRM)
Billing	Subscriptions, invoices, payments
System	Platform-level settings and admin

Sections in This Guide

• Getting Started — local setup, environment variables, Docker
• Authentication — JWT, roles, permissions, rate limiting
• API Reference — all endpoints documented by module
• Database — schema, migrations, entity overview
• Deployment — Docker, profiles, Cloud Run, Dokploy

Interactive API Docs

When the server is running, Swagger UI is available at:

http://localhost:8080/swagger-ui.html

OpenAPI spec:

• JSON: http://localhost:8080/v3/api-docs
• YAML: http://localhost:8080/v3/api-docs.yaml