Webview Bundle

An offline-first web resource delivery system for webview-mounted frameworks and platforms.

Webview Bundle (wvb) is an offline-first web resource delivery system for webview-mounted frameworks and platforms. It packs your built web assets (HTML/JS/CSS/media) into a single compressed, integrity-checked archive (.wvb) that your app ships with and serves to its webview through a custom URL scheme — and can update over the air without an app-store release.

 build output            .wvb archive              your app's webview
┌──────────────┐  pack  ┌───────────────┐  serve  ┌────────────────────┐
│ dist/        │ ─────▶ │ app_1.0.0.wvb │ ──────▶ │ app://app/index.html│
│  index.html  │        │  (compressed, │         │  (offline, instant) │
│  app.js …    │        │   verified)   │         └────────────────────┘
└──────────────┘        └───────────────┘
                              │  upload + deploy        ▲ download + verify
                              ▼                         │
                        ┌───────────────┐   updater     │
                        │ remote server │ ──────────────┘
                        └───────────────┘

Why Webview Bundle?

Offline-first. Resources are bundled locally, so the first paint never waits on the network.
Over-the-air updates. Ship a fix or feature by deploying a new bundle version — no native release required.
Integrity & authenticity. Every bundle carries checksums, and downloads can be verified with SHA-3 integrity hashes and digital signatures (ECDSA, Ed25519, RSA).
One format, every platform. The same .wvb archive works in Electron, Tauri, Android, and iOS via a shared Rust core.

Start here

Concepts

The .wvb format, bundle sources, the manifest, channels, integrity, and signatures. Read this first; the platform guides assume these terms.

Remote updates & local testing

Pack, upload, deploy, and update bundles over the air — and how to test the whole loop locally.

CLI reference

The wvb command-line tool: pack, serve, upload, deploy, download, and the local remote.

Configuration reference

The wvb.config file: pack, remote, serve, and builtin options.

Then pick your platform guide:

Electron

Serve a bundle through a custom protocol in an Electron app.

Tauri

Add the wvb-tauri plugin to a Tauri v2 app.

Android

Serve a WebView from a bundle with the Kotlin bindings.

iOS

Serve a WKWebView from a bundle with the Swift bindings.

Packages

Package	What it is	Where it runs
`wvb`	Rust core: bundle format, source, remote, updater, protocol, integrity, signature	everywhere (library)
`@wvb/cli` (`wvb`)	Command-line tool: pack, serve, upload, deploy, download, local remote	your machine / CI
`@wvb/config`	`defineConfig` for `wvb.config.ts`	build tooling
`@wvb/node`	N-API bindings to the core	Node.js
`@wvb/electron`	Electron integration (protocols, IPC, updater)	Electron main/renderer
`wvb-tauri`	Tauri plugin (protocols, commands, updater)	Tauri app
`wvb-ffi`	UniFFI bindings (Kotlin/Swift)	Android / iOS
`@wvb/remote-*`	Remote server providers (local, AWS, Cloudflare)	your update backend

The bundle format in one line

A .wvb file is [ Header | Index | Data ]: a 17-byte header (magic number, version, index size, checksum), an index mapping each file path to its location and HTTP metadata, and an LZ4-compressed data section. The full byte-level spec lives in the wvb crate docs.

Introduction