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browser-db-sqlite-persistence: option to load the wa-sqlite WASM by URL instead of inlined base64 #2101
Description
What
@tanstack/browser-db-sqlite-persistence (seen on 0.2.30) ships its OPFS worker prebuilt as dist/assets/opfs-worker-*.js, with wa-sqlite's WebAssembly inlined as a data:application/wasm;base64,… URL. That makes the worker about 1.7 MB raw (about 573 KB brotli). Most of that is the base64 WASM, which compresses worse than the binary and cannot be compiled by WebAssembly.instantiateStreaming.
src/opfs-worker.ts calls SQLiteESMFactory() with no options, and the package offers no option to pass a locateFile, a wasmBinary or a worker of one's own.
Ask
An option for where the WASM comes from. Any of these would do:
- a
wasmUrl(orlocateFile) option onopenBrowserWASQLiteOPFSDatabase, passed to the worker and on toSQLiteESMFactory({ locateFile }); - a
createWorkeroption, so an app can build the worker from source with its own bundler; - or ship the worker without inlining the WASM, since
@journeyapps/wa-sqlitealready resolvesnew URL("wa-sqlite.wasm", import.meta.url), which Vite, Rollup and webpack all emit as a separate asset.
What we do meanwhile
We patch dist/esm/opfs-worker.js so the consumer's Vite build makes the worker from the package's own source:
function WorkerWrapper(options) {
return new Worker(new URL("../../src/opfs-worker.ts", import.meta.url), {
type: "module",
name: options?.name
});
}With Vite 8 that gives an 88 KB worker plus a separate 1,129,661 B wa-sqlite-*.wasm: 468 KB brotli in total instead of 573 KB, compiled by streaming. It works in dev too, because Vite's dep optimizer rewrites the worker URL. We would like to drop the patch once the package has an option for it.
Activity
KyleAMathews commentedon Oct 11, 2026
Could you test out #2103 to see if it just works for y'all? I'd rather not add a option unless we really need to.
KyleAMathews commentedon Oct 21, 2026
@lloydclosson lemme know when you have a chance to test it — we're doing the first DB 1.0 RC soon so I'd like to make this change before then if possible
jackmccloy commentedon Oct 25, 2026
I ran into this too, and wanted to post another use case for this.
Use case: strict CSP. Because the worker embeds the WASM as a
data:URI, our app has toallow
connect-src 'self' data:just so Emscripten can fetch it. Withoutdata:, the openfails in the worker with:
Test of #2103 (head
0bca94e). I built the package from the PR branch and dropped it intoour app (React 19, Vite production build, Chromium) in place of 0.2.32. The app runs under an
enforced CSP of
connect-src 'self'(nodata:) andscript-src 'self' 'wasm-unsafe-eval'.the OPFS mirror while the API is down.
it emits a 209 kB worker (down from 1.7 MB) and a hashed
wa-sqlite-*.wasmalongside it.We'd drop
data:from our CSP once this ships. Thanks!