geezer-workshop / pglite

Lightweight Postgres packaged as WASM into a TypeScript library for the browser, Node.js, Bun and Deno

PGlite - Postgres in WASM

PGlite is a WASM Postgres build packaged into a TypeScript client library that enables you to run Postgres in the browser, Node.js and Bun, with no need to install any other dependencies. It is only 3.7mb gzipped.

import { PGlite } from "@electric-sql/pglite"

const db = new PGlite()
await db.query("select 'Hello world' as message;")
// -> [ { message: "Hello world" } ]

It can be used both as an ephemeral in-memory database or with persistance to the file system (Node/Bun) or indexedDB (Browser).

Unlike previous "Postgres in the browser" projects, PGlite does not use a Linux virtual machine - it is simply Postgres in WASM.

It is being developed at ElectricSQL in collaboration with Neon. We plan to continue to build on this experiment, and aim to create a fully capable lightweight WASM Postgres with support for extensions such as pgvector.

Node/Bun

Install into your project:

npm install @electric-sql/pglite

To use the in-memory Postgres:

import { PGlite } from "@electric-sql/pglite"

const db = new PGlite()
await db.query("select 'Hello world' as message;")
// -> [ { message: "Hello world" } ]

or to persist to the filesystem:

const db = new PGlite('./path/to/pgdata')

Browser

It can be loaded via JSDeliver or your usual package manager, and for an in-memory Postgres:

<script type="module">
import { PGlite } from "https://cdn.jsdelivr.net/npm/@electric-sql/pglite/dist/index.js";

const db = new PGlite()
await db.query("select 'Hello world' as message;")
// -> [ { message: "Hello world" } ]
</script>

or to persist the database to indexedDB:

const db = new PGlite('idb://my-pgdata')

Deno

To use the in-memory Postgres, create a file server.ts:

import { PGlite } from "npm:@electric-sql/pglite"

Deno.serve(async (_request: Request) => {
  const db = new PGlite()
  const query = await db.query("select 'Hello world' as message;")

  return new Response(JSON.stringify(query))
})

Then run the file with deno run --allow-net --allow-read server.ts.

Limitations

Parameterized queries are not currently supported, but this will be added soon.

Building

There are a couple of prerequisites:

• the Postgres build toolchain - https://www.postgresql.org/download/
• emscripten version 3.1.25 - https://emscripten.org/docs/getting_started/downloads.html

To build, checkout the repo, then:

git submodule update --init
cd ./pglite/packages/pglite
emsdk install 3.1.25
emsdk activate 3.1.25
pnpm install
pnpm build

Acknowledgments

PGlite builds on the work of Stas Kelvich of Neon in this Postgres fork.