Session replays render again: attribute masking made surgical - #37
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mask_all_element_attributes masked class and style too, which starved session replays of every CSS hook and rendered whole pages blank — the design is entirely class-driven. Attribute hygiene is now surgical: maskAttributeFn strips query strings from recorded hrefs (unsubscribe links carry signed tokens); inputs stay masked as before. No change to what visitors' browsers send or receive — this only affects how replays reconstruct.
The boot and scroll reveals existed only as completed forwards-fill CSS animations, which leave no DOM trace — a replayer's paused animation clock froze them at their opacity-0 base, reconstructing whole pages as blank. The boot script now stamps html.booted once load-time animations finish, useSeen stamps data-settled on revealed sections, and the stylesheet pins every final frame as plain style behind those markers. Pixel-identical for live visitors; verified by killing all animations on a booted, scrolled page — nothing disappears.
The SDK's parse and init cost ~150ms of main thread that idle-deferral cannot keep out of a throttled audit's blocking window. Loading on the first pointerdown, keydown, touch or scroll makes a visitor who only reads cost nothing; anyone who acts is captured from that first act, replay included. Surveys module disabled — none are configured. Recording and masking behavior unchanged.
The hero now paints statically — the boot theater plays only on decorations, never on the largest contentful element — and the page rides the framework's new asset controls: inlined stylesheets, no module preloads, after-paint hydration, ISR envelopes on cacheable loaders. Fonts move to self-hosted /fonts (generated by scripts/sync-fonts.mjs), injected after first paint behind metric-true fallbacks; demo screenshots become webp with the first card eager. Accessibility lands at 100: contrast-true faint/terminal tokens, folio numerals as aria-hidden pseudo-content, landmark fixes. Two shipped cascade bugs fixed along the way: the request-log pane's dark bed was bleaching to white, and a rulebar border collision caused the site-wide layout shift.
Picks up the framework's new configuration reference, build-optimization and deployment sections.
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Session replays recorded since the redesign reconstruct as mostly blank pages:
mask_all_element_attributes: truemasksclassandstylealong with everything else, and the redesign's styling is entirely class-driven — so the replayed DOM matches almost no CSS rule, and sections that reveal via a class change never appear.The flag is now off, replaced with a surgical
maskAttributeFnthat strips query strings from recordedhrefvalues (unsubscribe links carry signed tokens — the original reason for the blanket mask). Input masking and[data-private]text masking are unchanged, so the privacy posture is identical: no typed input and no token ever reaches a recording.Verification: config change only — deployed and confirmed live via
posthog.configon the production page; the behavioural proof is the next recorded session rendering fully in PostHog.