WPR runtime core

Shared Worker process lifecycle, named-pipe IPC, IOCP, shared-memory leases and versioned runtime resolution. This internal dependency is used by the standalone HTTP client and the unchanged WPR browser product. It contains no Page API, browser workflow or DOM interaction implementation.

Current native runtime support: Windows x86-64, Firefox 155, wpr-http-v1.

Runtime catalogs may select default_network_build independently of the browser's default_build. Network-only releases do not silently upgrade the browser product; exact version pins remain exact. Asking for an unbuilt product/version combination raises a compatibility error.

Persistent browser profile and official Widevine installation

Browser sessions use disposable profiles by default. For a persistent, version-bound profile, pass RuntimeConfig(persistent_profile_dir=...) (or set WPR_PERSISTENT_PROFILE_DIR). The directory is held by an exclusive lock for one Worker at a time and is rejected if its WPR application ID, version or build ID does not match. It is not deleted when the Worker exits. The profile contains site data, so treat it as sensitive and give each account/Worker its own directory. profile_root remains only a parent for disposable profiles.

RuntimeConfig(enable_widevine=True, persistent_profile_dir=...) enables Widevine installation through the Worker's Firefox GMPInstallManager. The browser client waits for download, verification and registration at startup. Firefox selects the platform component from official update metadata, verifies the downloaded archive, and stores the component and its preferences in the WPR profile. No Firefox installation or source Profile is required. The old widevine_source_profile / WPR_WIDEVINE_SOURCE_PROFILE import option now raises a migration error instead of copying components. Network-only Workers reject this browser capability. This requires the new runtime.widevine_* RPCs, available in Runtime 155.0.8 and later.

This is a capability boundary, not a promise of playback. Verify separately: requestMediaKeySystemAccess("com.widevine.alpha", ...), GMP/RDD/Utility subprocess launch, license response, media element readyState, video frames, and advancing currentTime. The source fix in source/gecko-net-worker/fixes/cdm-profile-lifecycle now links Firefox's sandbox broker through an isolated archive; a local release build passed both an open Widevine test and the target Shahid playback test. This source change is included in Runtime 155.0.8. Do not ship a diagnostic build that uses linker duplicate-symbol overrides or disables GMP/RDD/Utility sandboxing.

Opt-in media-output path probe

RuntimeConfig(media_capture=True) or WPR_MEDIA_CAPTURE=1 enables the Firefox 155 WPR metadata probe. The per-Worker log is read incrementally via WorkerSession.media_capture_snapshot(), AsyncWorkerSession.media_capture_snapshot(), or the browser client's AsyncGeckoRuntime.media_capture_snapshot(). It reports successful decrypt_sample and decode_frame output counts by track, timestamps and sizes, without saving media data or license/key material. buffer_bytes for decoded frames is allocated shared-memory capacity, not payload length. The option is browser-Worker-only and off by default. It requires a runtime built with media-capture-output.patch; existing published packages have not been updated with this feature.

For a short, bounded file capture, set RuntimeConfig(media_output_dir=Path(...)) or WPR_MEDIA_OUTPUT_DIR. The Worker writes per-session/per-CDM video.i420, audio.aac and JSONL timing sidecars. The default limit remains five seconds and 256 MiB of raw video; no output path is used by default. For an explicitly longer capture, configure media_output_max_seconds and media_output_max_bytes (or WPR_MEDIA_OUTPUT_MAX_SECONDS and WPR_MEDIA_OUTPUT_MAX_BYTES). The output is still raw I420, so callers must preflight free disk space and verify the final timeline before declaring a recording complete. The browser client's package_media_capture helper accepts max_seconds=None, expected_duration_seconds=..., and low_copy=True to encode the complete continuous capture directly from the source files without duplicating the raw video. Playback and site permissions remain the caller's responsibility.