videowright

name	videowright
description	Author HTML/CSS/JS animated explainer videos using Videowright. Trigger on requests to create a video, edit a segment, add or change a style, generate a VO script, run the dev server, or export.

Videowright

Videowright lets you author high-quality animated explainer videos in HTML/CSS/JS. Videos are composed from segments — self-contained TypeScript modules that own a DOM element and animate it. A Timeline orders segments with transitions, the dev server plays them interactively, and the render pipeline exports to MP4. The core authoring primitives are defineSegment, defineConfig, and the Timeline type.

When to trigger

• "Make me a video about X"
• "Add a segment to <video>"
• "Edit the intro of <video>"
• "Add a style" / "Change the default style"
• "Match the look of <past video>"
• "Generate a script for <video>"
• "Add a voiceover" / "Generate a voiceover" / "Record a voiceover"
• "Add sound effects" / "Add music" / "Add audio"
• "Run the dev server" / "Preview the video"
• "Export the video" / "Render the video"
• "Write tests for <video>"
• Any time videowright.config.ts is referenced or the user mentions Videowright

Setup gate

Before doing any work, check videowright.config.ts at the repo root:

• If the file does not exist, OR defaultStyle is missing or empty string: load references/setup.md and follow it before continuing.
• Otherwise: skip setup.md. Proceed with intent dispatch below.

Intent dispatch

Read the user's request and route to the matching reference file:

Intent	Reference
First-time setup of a Videowright project	references/setup.md
New video	references/new_video.md
Edit a video (add/remove/reorder segments, restyle, rewrite VO)	references/create_or_edit_video.md
Add a new style	references/setup_new_style.md
Change the default style	references/styles.md
Match a past video's style	references/styles.md
Generate or regenerate a VO script	references/audio.md
Add a voiceover (AI-generated or manual)	references/audio.md
Add sound effects or music	references/audio.md
Run or review the dev server	references/dev_server.md
Export the video	references/export.md
Write tests	references/testing.md

If the user's request does not map to a clear intent, ask one focused question listing the options above. Do not guess.

Core principles

• Use defineSegment always. It is the canonical authoring path. It handles beat tracking, abort signals, and typing.
• Fill the frame. Text and visual elements should be large, legible, and use the full video canvas — body text 36px+ at 1080p, headings 64px+, content containers spanning 80-90%+ of the video width. Avoid excessive margins, padding, or whitespace that shrinks content into a small portion of the frame. If text is too small to read comfortably at normal playback size, make it bigger or remove it. Small decorative labels are acceptable when intentional, but body text, headings, stats, and key visuals must dominate the frame. This is a video, not a web page — there is no scrolling, so every pixel of every frame matters.
• waitForNext() for audio-aligned beats; hold(ms) for pacing within a beat. Use ctx.waitForNext() at every point where the video should sync to an audio track advance — this keeps timing decoupled from any single audio recording, so swapping audio tracks only requires new timing data, not re-authoring segments. Use ctx.hold(ms) for pauses that are internal to a beat (entrance animations, dwell time before the next interactive point). Do not bake audio-specific durations into hold() calls — that couples the segment to one recording and forces re-authoring to swap narration.
• Render-safety CR on every segment. After writing or modifying a segment, review it against the render-safety checklist in references/create_or_edit_video.md (Step 2b). This catches patterns that work in dev but may produce suboptimal results in render (e.g., hold-driven mutation loops where WAAPI would give smoother interpolation).
• No duration field on segments. There is no duration property — the segment decides when it is done via its play() function.
• Any web tech is welcome inside segments. Three.js, Lottie, animated SVG, shadcn/React, GSAP, echarts — all encouraged. The segment owns its DOM; attach a shadow root if isolation is wanted.
• PLAN.md is the working memory. Read it before iterating on a video; append after meaningful changes. Never delete log entries.
• Reuse, don't copy. Top-level segments/, components/, transitions/ are shared across all videos. Any video can use any segment. Don't duplicate.
• Audio-first authoring is the default for new videos with VO. Write the script, then scaffold segments to match. This produces coherent videos.
• One-shot when the input is rich. Never ask a question whose answer is already in the user's input. When the user provides a complete brief, draft the plan and confirm — don't interrogate.