render-imessage-cascade

The free, deterministic renderer for the imessage-notification-cascade video ad format — the viral iOS trend where a phone sits on a desk and Apple Messages notifications STACK IN one after another. The signature mechanic is the bottom-up push: each new banner springs in at the bottom (nearest the phone) and shoves every existing one UP a row; the iOS grouped "⌄ Show less / ✕" pill rides above the stack; the ✕ clears the stack; then a serif end card resolves.

This is a DETERMINISTIC composite — no generative video of the UI. Authentic iMessage banners are drawn in PIL and animated in FFmpeg over a Ken-Burns plate, so the notification text + wordmark stay pixel-crisp (a video model would smear type). The template recipe supplies the per-brand plate, notifications, and end_card config and gates the only paid steps — cleaning the plate (→ create-image-fal) and the music bed/pop (→ create-music-elevenlabs) — to their own capabilities. This capability itself makes no paid calls.

Scripts (free)

• scripts/build_assets.py — draws the assets from config: nb-1..N.png (authentic banners — green Messages icon, warm translucent-greige fill, soft box-shadow, title/body/NOW/handle), pill.png (right-aligned "⌄ Show less / ✕"), endcard.png (serif CTA + wordmark lockup + url). Fonts are load-bearing: SF Pro (SFNS.ttf) via set_variation_by_name for the banner title/body/NOW/handle (Arial fallback), Times/serif for the end-card CTA. Do NOT swap in Helvetica/Arial as the primary — the banners must read as the real iOS system font.
• scripts/compose.py — Ken-Burns push-in on the plate → each banner springs in at the BOTTOM while later arrivals push the stack UP (FFmpeg overlay y expressions) → pill rides above → ✕-clear swipes the stack up + fades → serif end card fades in → optional audio (bed + pop per arrival + a free FFmpeg swoosh on the clear) → encode h264 + aac.
• scripts/config.example.json — the shape of the brand config the recipe binds.

Geometry contract (load-bearing — build_assets.py and compose.py MUST share it)

W=1080 H=1920, SIDE=135 → banner width BODY_W=810, BANNER_H=176, PAD=60, row pitch H=214, bottom anchor YB=1200. Icon ~100px at a ~24px left inset; body text starts ~150px from the banner's left edge. Change one, change both.

Craft rules (faithful to the source molecule)

• Keep the REAL iMessage UI: green Apple Messages icon, warm TRANSLUCENT greige banner (NOT white, no white bloom), soft dark box-shadow. Do NOT rebrand the banner to the brand's colors — the brand lives ONLY on the handle (bottom-right) + the end card.
• SF Pro for all banner text (title Semibold ~38, body Regular ~36, NOW/handle ~25). Never AI-render text.
• 3–5 notifications (more crowds the top / clips the pill); newest enters at the BOTTOM, so banner 1 is the oldest and ends up on TOP.
• ✕-clear then end card (a real hand-swipe needs a paid i2v — out of scope here).

Requires

watch (QC the final master). The recipe gates create-image-fal (plate clean) and create-music-elevenlabs (bed/pop) — both paid, proxy-routed, billed to the Ads agent.