Getting started

Mirror ORM is an ultra-high performance Data Mapper for Node.js, focused on near-zero overhead and strict typing. It uses JIT (Just-In-Time) compilation to ensure that entity hydration is the fastest in the ecosystem.

1. Installation

Install the database core and driver you will use:

# PostgreSQL
pnpm add mirror-orm pg

# MySQL / MariaDB
pnpm add mirror-orm mysql2

# SQLite
pnpm add mirror-orm better-sqlite3

# SQL Server
pnpm add mirror-orm mssql

2. TypeScript Configuration

Mirror uses native Stage 3 Decorators (TS 5.0+). Unlike other ORMs, do not enable experimentalDecorators, as Mirror follows the native TC39 standard.

In your tsconfig.json:

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "ESNext",
    "moduleResolution": "bundler"
  }
}

Node 20 note: Mirror automatically injects the polyfill for Symbol.metadata. You don’t need extra configuration for decorators to work in Node.js v20.20.1+.

3. Establishing Connection

Mirror offers named static methods for each bank, accepting both a Connection String and a detailed configuration object.

1. Postgres

Uses the pg driver. Supports SSL and Read Replicas.

import { Connection } from 'mirror-orm';

// Connection String
await Connection.postgres('postgresql://user:password@localhost:5432/dbname');

// Objeto de Configuração
await Connection.postgres({
  host: 'localhost',
  user: 'admin',
  password: 'password',
  database: 'mirror_db',
  port: 5432,
  ssl: true // Necessário para Neon/Supabase/RDS
});

2. MySQL

Uses the mysql2 driver.

import { Connection } from 'mirror-orm';

// Connection String
await Connection.mysql('mysql://user:password@localhost:3306/dbname');

// Objeto de Configuração
await Connection.mysql({
  host: 'localhost',
  user: 'root',
  password: 'password',
  database: 'mirror_db'
});

3. SQLite

Uses the better-sqlite3 driver. Since SQLite is a local file, the URL is the file path.

const conn = await Connection.sqlite({ database: './app.db' });

4. SQL Server (MSSQL)

Uses the mssql driver.

import { Connection } from 'mirror-orm';

// Connection String
await Connection.sqlServer('mssql://user:pass@localhost:1433/db?encrypt=true');

// Objeto de Configuração
await Connection.sqlServer({
  server: 'localhost',
  user: 'sa',
  password: 'Password123!',
  database: 'mirror_db',
  options: { encrypt: true, trustServerCertificate: true }
});

4. First entity

The mapping in Mirror is explicit to ensure that JIT Hydrator knows exactly what to process.

import { Entity, Column, PrimaryColumn, CreatedAt, UpdatedAt } from 'mirror-orm';

@Entity('users')
class User {
    @PrimaryColumn({ strategy: 'identity' })
    id!: number;

    @Column()
    name!: string;

    @Column({ nullable: true })
    email!: string | null;

    @CreatedAt()
    createdAt!: Date;

    @UpdatedAt()
    updatedAt!: Date;
}

Next steps: See the complete decorator reference in Entities and Column Decorators. To make your first query, see the Repository API.