---
name: sum-parts
description: Explain a whole by assembling one to three photographed parts with plus and equals signs, then reveal quantities in an editable short video.
version: 1.0.0
---

# Sum Parts

Use for a compact composition where photographed inputs combine into one outcome. This is a parameterized HTML/GSAP renderer. The Agent authors a brief, verifies the arithmetic and supplies licensed local photos. It does not invent suitable factual data or acquire media automatically.

Read [the input guide](references/brief.md) and [motion guidance](references/motion.md). Keep concepts concise, use actual raster images, and specify whether numbers are illustrative. Check that all quantities share one unit. The renderer adds numeric amounts; it does not convert units or calculate taxes.

Use Node.js 22 LTS, FFmpeg with ffprobe, and HyperFrames 0.8.30. GSAP 3.13.0, Inter and Noto Sans SC are bundled with required notices. Run from the extracted directory:

```sh
node scripts/create.mjs --brief /absolute/brief.json --project /absolute/new-project --palette linen
node scripts/render.mjs /absolute/new-project /absolute/film.mp4
```

Choose `linen`, `fjord`, `terracotta`, or `carbon`. The shot is 1920 × 1080, 30 fps, 6.6 seconds. Each project contains editable HTML, copied media, resolved brief, timeline and a build manifest. `--font /absolute/font.woff2` overrides typography; Chinese text otherwise selects Noto Sans SC. Asset paths resolve beside the brief. Existing project destinations are rejected.

Inspect the actual encoded first state, operator arrivals, result entrance, delayed numbers and final hold. Test forward and reverse seeking, including zero, via `window.seek(seconds)` or `window.__timelines['sum-parts']`. Check photo crops, readable labels, sums, overflow and complete MP4 decoding. All themes share content and motion. A successful render does not establish visual acceptance.

The output is silent. No soundtrack, presenter performance, alpha matte or audio editor is included. Add licensed sound in a separate editor when the brief requests it, and verify the resulting mix independently. Example photos and completed demo media are intentionally outside the reusable ZIP. Retain asset credits with each project and distributed film.