Installation

Packages

npm install @runanywhere/web @runanywhere/web-llamacpp @runanywhere/web-onnx @runanywhere/proto-ts

Package	Version	Exports
`@runanywhere/web`	`0.20.24`	`RunAnywhere`, `AudioInput`, `ImageInput`, `RagDocument`, `SDKException`, `isSDKException`, types
`@runanywhere/web-llamacpp`	`0.20.24`	`LlamaCPP`, `autoRegister`: LLM, VLM, embeddings, LoRA, tools, structured output
`@runanywhere/web-onnx`	`0.20.24`	`ONNX`, `autoRegister`, `onnxStatus`: STT, TTS, VAD, ONNX embeddings
`@runanywhere/proto-ts`	`0.20.24`	Generated protobuf types for models, events, errors, modalities

npm install pulls the WASM artifacts with the packages. There is no separate WASM build step and no Emscripten toolchain to install.

Cross-origin isolation

This is the one thing that stops a first attempt working. The SDK needs SharedArrayBuffer, which browsers only expose to a cross-origin isolated page. Serve both headers:

Cross-Origin-Opener-Policy: same-origin
Cross-Origin-Embedder-Policy: require-corp

For Vite in development:

vite.config.ts

export default defineConfig({
  server: {
    headers: {
      'Cross-Origin-Opener-Policy': 'same-origin',
      'Cross-Origin-Embedder-Policy': 'require-corp',
    },
  },
})

For Vercel:

vercel.json

{
  "headers": [
    {
      "source": "/(.*)",
      "headers": [
        { "key": "Cross-Origin-Opener-Policy", "value": "same-origin" },
        { "key": "Cross-Origin-Embedder-Policy", "value": "require-corp" }
      ]
    }
  ]
}

Where you cannot set headers, a service worker can add them client-side. That is what coi-serviceworker.js does, and it is also what forces the one-time reload you will see on Safari. If you see SharedArrayBuffer is not defined, the page is not isolated. Nothing else is wrong.

Registering a backend

import { RunAnywhere } from '@runanywhere/web'
import { LlamaCPP } from '@runanywhere/web-llamacpp'
import { ONNX } from '@runanywhere/web-onnx'

await LlamaCPP.autoRegister()
await ONNX.autoRegister()

await RunAnywhere.initialize({ environment: 'development' })

autoRegister picks the CPU or WebGPU build for the current browser.

Build-time configuration

For a hosted deployment, two Vite variables boot the SDK straight into production:

Variable	Meaning
`VITE_RUNANYWHERE_API_KEY`	Publishable browser key. Never a server-side secret; Vite inlines it into the bundle.
`VITE_RUNANYWHERE_BASE_URL`	Production API origin

Both must be set, or the app boots in the development environment.

Where models are stored

Downloads land in OPFS by default, which is private to the origin. The user can grant a real directory instead. See Configuration.

Troubleshooting

Symptom	Fix
`SharedArrayBuffer is not defined`	The page is not cross-origin isolated. Add both headers.
Build fails naming missing `racommons-*` files	The SDK packages did not install completely. Re-run `npm ci`.
Model download stalls or workers hang	Hard-reload to clear a stale service worker, then recheck the headers.
A WebGPU model produces garbage	Switch that model to the CPU variant.

Getting Started

Swift SDK

Kotlin SDK

React Native SDK

Flutter SDK

Web SDK

Electron SDK

Vibe Coding

Packages

Cross-origin isolation

Registering a backend

Build-time configuration

Where models are stored

Troubleshooting

​Packages

​Cross-origin isolation

​Registering a backend

​Build-time configuration

​Where models are stored

​Troubleshooting

Packages

Cross-origin isolation

Registering a backend

Build-time configuration

Where models are stored

Troubleshooting