playground.actcore.dev

Live: https://playground.actcore.dev

A browser-native AI agent stack. Paste a wasm component URL, the tool loads and runs in your tab. No server, no Node, no install.

What this is

A demonstration of @actcore/host — a browser host for ACT components. Each tool is a wasm component packed with act-build, distributed via an OCI registry, and signed by its author. The playground:

1. Resolves a URL (oci://, https://, or a dropped .wasm file).
2. Pulls the bytes (OCI fetches go through oci-cors-proxy so the browser sees permissive CORS).
3. Verifies the SHA-256 of the bytes against the OCI manifest digest.
4. Transpiles the component in-page via @bytecodealliance/jco.
5. Instantiates it (WebAssembly Component Model, wasip3-async, JSPI).
6. Exposes its act:tools/tool-provider so you can click "Run" and see the output.

In a follow-up iteration, a local WebLLM Llama-3.2 will call these tools via function-calling — the full agent loop, in your tab, with no remote API key.

Run locally

This repo expects actcore/host-browser checked out as a sibling directory (the @actcore/host dependency is referenced via file:../host-browser).

git clone https://github.com/actcore/host-browser ../host-browser
cd ../host-browser && npm install && npm run build
cd -                                            # back to playground
npm install
npm run dev                                     # http://localhost:5173

Deploy

Pushed to main triggers .github/workflows/pages.yml, which:

1. Builds @actcore/host from the sibling repo (PAT required, see workflow).
2. Builds the playground with Vite.
3. Publishes to GitHub Pages.

Custom domain playground.actcore.dev set via public/CNAME.

Browser support

Requires JSPI. Chrome 137+ today; Firefox Nightly 152+ and Safari Tech Preview 243+ today. Stable Firefox/Safari shipping JSPI per Interop 2026.

License

MIT OR Apache-2.0