Backend API Overview

The Tower Defense backend is a NestJS application (apps/api). It handles authentication, account management, and data persistence for the game.

Architecture

Three shared libraries power the API:

• @tower-defense/auth — Better Auth integration and profile management
• @tower-defense/db — Drizzle ORM + MySQL schema
• @tower-defense/mail — Nodemailer transactional email delivery

Runtime Shape

• Entry point: apps/api/src/main.ts
• Global prefix: /api
• Port: reads from PORT env var, defaults to 3000
• CORS: enabled for https://td.traitor.app with credentials

What Each Library Owns

Library	Responsibility
auth	Session management, confirmation-token flows, blocked mutation policy
db	MySQL schema, connection pool, migration tooling
mail	SMTP transport, all outgoing email templates

Documentation Map

Goal	Page
Understand how auth and profile flows work	Authentication
Look up endpoint payloads and responses	Endpoints
Find required env vars and runtime settings	Configuration
Inspect the database schema	Database
See which mail is sent and when	Mail Service
Understand the complete client-to-API auth flow	Auth Flow End to End

New to the backend?

Read Getting Started for local setup instructions.