chdb-wasm browser shell

The browser SQL shell behind wasm.chdb.io — chDB (ClickHouse compiled to WebAssembly) running fully in the browser. SQL executes on the client, with no backend.

This repo is just the web page + its Cloudflare deploy. The engine itself (the WebAssembly build, the glue JS, and the .wasm) lives in the chdb-wasm npm package (built from chdb-io/chdb-core); this shell only consumes it.

Layout

• web/ — the static site: index.html (the shell), _headers (COOP/COEP + cache rules), _routes.json, and functions/[[path]].js (a Pages Function that streams the .wasm from R2). See web/README.md.
• scripts/build-cf-bundle.sh — assembles the Cloudflare deploy bundle (pages/ + r2/) from an engine dist/ and web/, content-hashing the engine dir for immutable caching.
• scripts/serve.mjs — local preview server (sets COOP/COEP).
• .github/workflows/deploy.yml — manual-only (workflow_dispatch) deploy to Cloudflare.

Local preview

npm install                 # pulls the chdb-wasm engine into node_modules/
npm run serve               # http://localhost:8099  (use localhost for SharedArrayBuffer)

index.html loads the engine from ./dist; the preview server maps /dist/* to the installed chdb-wasm package. To preview an unpublished local build instead, symlink it:

mkdir -p node_modules && ln -s /path/to/chdb-core/packages/chdb-wasm node_modules/chdb-wasm

Deploy

Manual only, via the Deploy wasm shell to Cloudflare workflow (Actions → Run workflow). It pulls a published chdb-wasm version from npm, assembles the bundle, puts the .wasm in R2, and deploys the rest to Pages. Inputs: chdb_wasm_version, pages_project, r2_bucket.

One-time prerequisites (by the Cloudflare account owner):

• Repo secrets CLOUDFLARE_API_TOKEN (Cloudflare Pages — Edit, Workers R2 Storage — Edit) and CLOUDFLARE_ACCOUNT_ID.
• An R2 bucket bound to the Pages project as WASM_BUCKET, and the wasm.chdb.io custom domain.