Browser inference

The browser package pairs Rust inference with thin JavaScript bindings. Build the package in the runtime repository, then serve it from your host application.

Build the bindings#

Use Node 22 or newer, Rust 1.89.0, and the pinned WASM binding tool.

npm ci
cargo install wasm-bindgen-cli --version 0.2.127 --locked
npm run build:web

The build writes minifield_web_demo.js and minifield_web_demo_bg.wasm into web/pkg/. Distribute both files together. Serve WASM with application/wasm.

Initialize the module#

import init, { configure_telemetry } from './runtime/minifield_web_demo.js';

const response = await fetch('./runtime/minifield_web_demo_bg.wasm');
if (!response.ok) throw new Error('Runtime WASM could not be loaded.');
const bytes = await response.arrayBuffer();

await init({ module_or_path: bytes });
configure_telemetry({
  integrationId: 'contact-extraction',
  productId: 'contact-editor',
  environment: 'production',
});

Initialize and configure the runtime in the same Worker that performs inference. Passing WASM bytes also supports importing the JavaScript from a blob URL.

Select a binding#

load and generate handle greedy language-model inference with incremental token callbacks. generate_json applies byte-level grammar masks during generation.

load_classifier accepts an explicit dense head with shape [classes, hidden]. classify starts fresh state. classify_cached reuses shared prefix state where possible. choose scores criterion tails after a shared prefill.

Use the generated TypeScript declarations for exact binding signatures. The host supplies the prompt and validates the resulting product data.

Try the development harness#

Put a bundle under models/demo/ in the runtime checkout, then serve the repository:

python3 -m http.server 8642 --bind 127.0.0.1

Open http://localhost:8642/web/index.html?bundle=../models/demo. The browser must expose a WebGPU adapter.

Qualify an actual browser#

scripts/check.sh browser \
  --bundle /absolute/bundle \
  --prompts /absolute/prompts.json \
  --classes 8 \
  --expected /absolute/native-result.json \
  --out /absolute/browser-result.json

The check loads the exact assets in Chrome, compares classification results, exercises cached execution and recovery, and records browser and adapter identity. Keep these results with the bundle’s release evidence.