docs: expand README with setup instructions and environment variables…

README.md

@@ -1,2 +1,71 @@
 # Future Self API
-A nestjs app
+
+NestJS API with PostgreSQL (TypeORM), Redis (BullMQ queues), and email via Brevo.
+
+## Prerequisites
+
+- **Node.js** 22.x or current LTS (matches the project’s `@types/node` range)
+- **PostgreSQL**
+- **Redis**
+- A **Brevo** account and API key if you plan to send real emails
+
+## Setup
+
+1. **Install dependencies**
+
+   ```bash
+   npm install
+   ```
+
+2. **Environment variables**
+
+   The app loads `.env.local` first, then `.env.prod` ([`app.module.ts`](src/app.module.ts)). Create a `.env.local` in the project root for local development.
+
+   Required variables are defined in [`src/commons/interfaces/env.ts`](src/commons/interfaces/env.ts). Example for local development:
+
+   ```env
+   NODE_ENVIRONMENT=local
+   APP_PORT=3000
+   APP_KEY=your-secret-signing-key-change-me
+   ENABLE_RATE_LIMITING=false
+   DONT_SEND_EMAIL=true
+
+   REDIS_HOST=127.0.0.1
+   REDIS_PORT=6379
+   REDIS_USER=
+   REDIS_PASSWORD=
+
+   POSTGRES_USER=postgres
+   POSTGRES_PASSWORD=postgres
+   POSTGRES_DB=future_self
+   POSTGRES_HOST=127.0.0.1
+   POSTGRES_PORT=5432
+   POSTGRES_HOST_DOCKER=postgres
+
+   EMAIL_SENDER_NAME=Future Self
+   EMAIL_SENDER_EMAIL=noreply@example.com
+   BREVO_API_ENDPOINT=https://api.brevo.com/v3
+   BREVO_API_KEY=your-brevo-api-key
+   ```
+
+   Adjust `POSTGRES_*` and `REDIS_*` to match your running services. Use a strong `APP_KEY` in any shared or deployed environment.
+
+3. **Start PostgreSQL and Redis** on the hosts and ports you configured (for example with local installs or your own Docker setup).
+
+4. **Run the app**
+
+   ```bash
+   npm run start:dev
+   ```
+
+   The server listens on the port set by `APP_PORT` (see log: `Server running on …`).
+
+## Other scripts
+
+| Command | Purpose |
+|--------|---------|
+| `npm run build` | Production build |
+| `npm run start:prod` | Run compiled app from `dist` |
+| `npm run lint` | ESLint |
+| `npm run test` | Unit tests |
+| `npm run test:e2e` | E2E tests |