@monlite/wasm

Run @monlite/core in the browser on SQLite compiled to WebAssembly, via sql.js.

monlite's driver-adapter seam means the browser is just another backend — the document and structured collection API, reactive watch(), and the kv/queue/cron harness all run unchanged, in-browser, no server required.

npm install @monlite/core @monlite/wasm sql.js

Quick start

initSqlJs is async (it loads the .wasm binary), so initialise it first, then hand the module to wasmDriver. createDb itself stays synchronous.

import initSqlJs from "sql.js";
import { createDb } from "@monlite/core";
import { wasmDriver } from "@monlite/wasm";

const SQL = await initSqlJs({
  locateFile: (file) => `/sqljs/${file}`, // point at where your bundler serves sql-wasm.wasm
});

const db = createDb(":memory:", { driver: wasmDriver(SQL) });

await db.collection("notes").create({ data: { title: "hello", body: "from the browser" } });
const notes = await db.collection("notes").findMany({ where: { title: "hello" } });

Bundler note: copy node_modules/sql.js/dist/sql-wasm.wasm to a served path and return it from locateFile. For Vite, put it in public/sqljs/.

Persistence

sql.js holds the database in memory. To persist it across page loads, snapshot the bytes to IndexedDB (or OPFS) and restore them on startup:

import { wasmDriver, exportDatabase } from "@monlite/wasm";

// On startup: restore from IndexedDB if a previous snapshot exists
const saved = await idbGet("monlite-db"); // Uint8Array | undefined
const db = createDb(":memory:", { driver: wasmDriver(SQL, { data: saved }) });

// After writes (debounced) or on beforeunload: persist
async function persist() {
  await idbSet("monlite-db", exportDatabase(db));
}

A reactive debounce works well here: subscribe with collection.watch() and call persist() on a trailing debounce after each change.

Sync with the server

A monlite WASM database uses the same SQLite format as the Node backends, so it syncs with a server or another device through @monlite/sync like any other monlite database.

Notes

• sql.js runs in Node as well, so @monlite/wasm is covered by the normal test suite.
• Snapshotting rewrites the whole file, which is fine up to tens of MB. For larger, write-heavy databases the planned next step is a driver over @sqlite.org/sqlite-wasm with the OPFS VFS (incremental persistence via a Web Worker). Same Driver interface, drop-in.

License

MIT