Compatibility

The current public compatibility line is Manifest V1.

Surface	Public contract	Runtime
@vifu/sdk	Browser SDK for Vifu capabilities, resources, and game-owned actions	Vifu Web iframe, iOS WKWebView
@vifu/cli	Setup, build, deploy, and artifact validation	Node.js CLI
@vifu/create-vifu	Starter project initializer	Node.js CLI

Version Policy

Patch and alpha releases may add SDK helpers, diagnostics, manifest fields, and deploy validation rules, but they should not silently break valid Manifest V1 projects.

Breaking changes require a new documented compatibility line. Until then, games should use:

• manifestVersion: 1
• main.url for the browser entry file
• @vifu/sdk
• Vifu SDK APIs instead of host bridge messages

Host Requirements

• Browser runtime with window.postMessage for Vifu Web.
• window.webkit.messageHandlers.vifuHost for the iOS WKWebView runtime.
• Static browser output with an HTML entry file.
• JSON-serializable context, command input, command result, observation, and signal payloads.
• Platform services accessed through @vifu/sdk, not direct backend calls.

What Is Not Stable Yet

These surfaces are platform-internal during alpha:

• compiled runtime policy names
• provider manifests
• moderation and review internals
• worker/eval/security rule names
• raw host bridge messages

Use the public SDK, CLI, and Manifest V1 docs instead of depending on internal runtime details.