every.channel/evolution/proposals/ECP-0095-native-macos-webview-first-for-nbc-auth-and-playback.md

ECP-0095: Native macOS Webview First for NBC Auth and Playback

Status: Proposed

Decision

On macOS, the Tauri app should attempt NBC playback through an in-app WebviewWindow backed by WKWebView before launching an external browser.

The native path will:

• create a dedicated NBC auth/player window inside the app with a persistent webview data directory
• keep Adobe Pass / MVPD interaction inside the native app window, including popup sign-in flows
• use native WKWebView JavaScript evaluation and snapshot APIs to drive readiness checks and capture rendered frames for ffmpeg

The existing Chrome-backed path remains as a fallback when native playback cannot become ready.

Motivation

The first NBC implementation proved that browser-backed capture is the right source model, but it still pushes authentication into an external Chrome session. For the desktop app, that is a worse operator experience than a native in-app window and makes session management less coherent.

Tauri 2 already exposes the platform webview and, on macOS, gives access to the underlying WKWebView. That is enough to move the login and capture loop in-process without redesigning the rest of the CMAF ladder or MoQ publish flow.

Scope

In scope:

• macOS-only WKWebView session creation for NBC sources
• popup/new-window handling for MVPD login flows
• native JavaScript probing plus native snapshot capture for the existing frame pipeline
• automatic fallback to the existing Chrome path when native playback fails to get ready

Out of scope:

• removing the Chrome fallback entirely
• guaranteeing DRM parity with Chrome across every NBC playback variant
• audio capture changes beyond the current video-first path

Alternatives Considered

• Keep the external Chrome-only path. Rejected because the native app can host the auth/player surface directly on macOS.
• Replace the entire source implementation with custom CEF/Chromium embedding. Rejected because it is materially heavier than using Tauri's existing native webview APIs.
• Use an in-app webview only for login, then continue playback in Chrome. Rejected for the first pass because it still splits operator state across two browser stacks.

Rollout / Reversibility

• The change is additive and scoped to NBC handling in the Tauri app on macOS.
• If native playback proves unreliable for a given stream/auth path, the app falls back to the existing Chrome implementation automatically.
• Roll back by removing the native webview path and retaining the Chrome-backed implementation from ECP-0094.