Usage with PGlite

MikroORM supports PGlite — a WASM build of PostgreSQL that runs in Node.js, the browser, Bun and Deno without a separate database server. The @mikro-orm/pglite driver reuses the full @mikro-orm/postgresql SQL/schema/migrations stack via @mikro-orm/sql, so feature support matches the regular PostgreSQL driver.

Installation

npm install @mikro-orm/core @mikro-orm/pglite

Configuration

PGlite defaults to in-memory storage; pass a dbName only when you want to persist the database.

import { defineConfig } from '@mikro-orm/pglite';

export default defineConfig({
  entities: ['./dist/entities'],
  entitiesTs: ['./src/entities'],
});

Storage backends

The dbName option selects the PGlite storage backend:

// in-memory (default)
await MikroORM.init({ entities: [...] });

// persisted to a Node.js directory
await MikroORM.init({ entities: [...], dbName: './my-db' });

// persisted to IndexedDB (browser)
await MikroORM.init({ entities: [...], dbName: 'idb://my-db' });

See the PGlite documentation for the full list of supported dataDir schemes.

Driver options

Anything passed under driverOptions is forwarded to PGlite.create(), so you can register extensions, custom type parsers, etc.

import { defineConfig } from '@mikro-orm/pglite';
import { vector } from '@electric-sql/pglite/vector';

export default defineConfig({
  entities: [...],
  dbName: './my-db',
  driverOptions: {
    extensions: { vector },
  },
});

Reusing an existing PGlite instance

Pass an existing PGlite instance (or async factory) under driverOptions.pglite if you need to share it with non-ORM code, run multiple ORMs against the same database, or pre-load the WASM module yourself. MikroORM will not own the lifecycle — closing the ORM leaves your instance untouched, and the default type parsers are not applied (configure them on your own instance).

import { PGlite } from '@electric-sql/pglite';
import { MikroORM } from '@mikro-orm/pglite';

const pglite = await PGlite.create({ dataDir: './my-db' });

const orm = await MikroORM.init({
  entities: [...],
  driverOptions: { pglite },
});

Schema, migrations, and queries

PGlite implements standard PostgreSQL features, so the Schema Generator, Migrations, QueryBuilder, and Kysely integration all work the same way as with @mikro-orm/postgresql.

Limitations

• Streaming is not supported — PGlite does not expose cursor-based streaming. Use @mikro-orm/postgresql against a real PostgreSQL server if you need em.stream() or qb.stream().