Heroes3 API

A RESTful API for Heroes of Might & Magic 3

Tech Stack

• NestJS
• TypeScript
• PostgreSQL

Setup

1. Install dependencies

npm install

2. Environment

Copy the example env and adjust if needed:

cp .env.example .env.development

3. Start PostgreSQL (Docker)

docker compose up -d

4. Run migrations

Create or update the database schema:

npm run migration:run

If you already have tables from a previous synchronize: true setup, either use a fresh database or drop existing tables (and the migrations table if present), then run migration:run again.

5. (Optional) Seed data

Insert demo data (towns, heroes, units, etc.):

npm run seed

Seed is idempotent: it skips if data already exists.

6. Run the app

# development & watch mode
npm run start:dev

# production mode
npm run start:prod

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Migrations and seed

• Migrations define the schema (tables, columns, FKs). Always run npm run migration:run on a fresh DB or after pulling new migrations.
• Seed fills the DB with demo data; safe to run multiple times (no duplicates).

How to create a new migration

1. Change entities in src/ (add/remove columns, new tables, etc.).
2. Generate a migration from the diff:

   npm run migration:generate -- src/database/migrations/DescribeYourChange

   This creates a new file under src/database/migrations/ with up() and down().
3. Review the generated file, then run:

   npm run migration:run

Useful commands

Command	Description
npm run migration:run	Run all pending migrations
npm run migration:revert	Revert the last migration
npm run migration:generate -- src/database/migrations/Name	Generate migration from entity changes
npm run seed	Insert demo data (skips if already seeded)