remotion

[IMPORTANT] Use TaskCreate to break ALL work into small tasks BEFORE starting. Keep task depth proportional to the work. MUST ATTENTION wait for user approval of scene plan (Step 3.3) before writing any files — NEVER skip. MUST ATTENTION read existing project files before modifying — NEVER overwrite scenes blindly. MUST ATTENTION update totalChapters in ALL existing scene files when adding/removing scenes.

Be skeptical. Apply critical thinking. Every claim needs traced proof, confidence >80% to act.

Quick Summary

Goal: Create new Remotion video project, add/update scenes in existing one, or launch local Remotion Studio preview server.

Two Modes:

Mode	When	Action
Create / Update (default)	User describes video content OR asks to update/add scenes	Scaffold new project or modify existing scenes
Play	User says "play", "preview", "open studio", "watch", "start server"	Find Remotion project → `npm run studio`

Default project path: remotion/ (relative to workspace root). Respect any path user explicitly provides.

Key Rules:

NEVER implement scenes before user approves the plan (Step 3.3)
Always read existing project structure before adding/modifying scenes
Keep totalChapters consistent across ALL scene files
All animations MUST be driven by useCurrentFrame() — CSS transitions FORBIDDEN
Always use Remotion components (<Img>, <Video>, <Audio>) instead of native HTML elements

Implementing one of these? Copy from refs/ — do NOT implement from memory:

Implementing...	Copy from
`{source-root}/components/Shared.tsx` (new scaffold)	`refs/Shared.tsx` — C palette, ProgressBar, ChapterBadge, CodeBlock, Pill, AnimRow
`{source-root}/utils/animations.ts` (new scaffold)	`refs/animations.ts` — easeOut, easeInOut, pop, staggeredEaseOut, counter
Typewriter or word-highlight text effect	`refs/text-animations.tsx` — getTypedText, Cursor, TypewriterScene, Highlight
TikTok-style captions with word highlight	`refs/captions.tsx` — CaptionedVideo, CaptionPage, delayRender, createTikTokStyleCaptions
Video/audio duration, dimensions, frames	`refs/mediabunny-utils.ts` — getVideoDuration, getAudioDuration, getVideoDimensions, canDecode, extractFrames
Mapbox map scene	`refs/maps-mapbox.tsx` — MapScene component, interactive:false, camera animation
ElevenLabs TTS voiceover generation	`refs/generate-voiceover.ts` — TTS script + calculateMetadata integration

Quick Summary
Phase 0: Mode Detection
Phase 1A: Detect Existing Project
Phase 2: PLAY Mode
Phase 3: CREATE / UPDATE Mode
Update Mode: Specific Scenarios
Remotion API Reference
Closing Reminders

Phase 0: Mode Detection

Classify prompt:

PLAY keywords   → "play", "preview", "open studio", "start server", "watch", "launch", "dev server"
CREATE/UPDATE   → everything else (default)

Ambiguous → proceed with Create/Update (safe default).

Phase 1A: Detect Existing Project

Locate Remotion project before acting:

# Check default path
ls remotion/package.json 2>/dev/null

# Check if CWD is already a Remotion project
ls package.json 2>/dev/null | xargs grep -l '"remotion"' 2>/dev/null

# Check common paths
find . -maxdepth 3 -name "package.json" -exec grep -l '"remotion"' {} \; 2>/dev/null | head -5

State after detection:

PROJECT_EXISTS = true/false
PROJECT_PATH = remotion/ (default) or detected path
HAS_STUDIO_SCRIPT = true/false (check package.json scripts.studio)

Phase 2: PLAY Mode

When: User explicitly asks to preview / open studio / launch dev server.

Read references/remotion-play-mode.md when Phase 0 selects PLAY; it holds Steps 2.1–2.4: exit with the create hint when PROJECT_EXISTS = false, find the launch command (npm run studio, fallback npx remotion studio), start the dev server in the background and report the URL and composition IDs, and the optional one-frame render check.

Phase 3: CREATE / UPDATE Mode

Step 3.1 — New vs Update Decision

Condition	Action
`PROJECT_EXISTS = false`	Scaffold new project → Phase 3.2
`PROJECT_EXISTS = true`	Read existing project → Phase 3.4

Step 3.2 — Scaffold New Project

Read references/remotion-scaffold.md when PROJECT_EXISTS = false; it holds 3.2.1 bootstrap with npx create-video@latest --yes --blank --no-tailwind (preferred), the manual fallback, the directory structure, the package.json scripts, tsconfig.json, index.ts, and the copy-from-refs/ rule for Shared.tsx and animations.ts.

Step 3.3 — Plan Composition Structure

MUST ATTENTION wait for user confirmation before implementing any scenes.

Plan composition before writing files:

Parse intent — What video about? What information to convey?
Decide scene count — 1 scene per major concept (30s → ~4 scenes, 60s → ~8, 90s → ~12)
Assign durations — Each scene: 6–12s (180–360 frames @ 30fps)
Name scenes — Scene01Intro, Scene02{Topic}, etc.
Write scene brief — what shown, key data, visual layout (left/right split, full-width, grid)

Present plan before writing files:

Proposed: {N} scenes, ~{total}s total
  Scene 01 ({Xs}) — {topic}: {layout description}
  Scene 02 ({Xs}) — {topic}: {layout description}
  …
Proceed? (or adjust)

Step 3.4 — Read Existing Project (UPDATE path)

MUST ATTENTION read existing project state before any modifications.

When PROJECT_EXISTS = true:

# Read composition registry
cat {PROJECT_PATH}/{source-root}/Root.tsx

# List scene files
ls {PROJECT_PATH}/{source-root}/compositions/ 2>/dev/null || ls {PROJECT_PATH}/{source-root}/scenes/ 2>/dev/null

# Read main composition orchestrator
cat {PROJECT_PATH}/{source-root}/ClaudeAgentExplainer.tsx 2>/dev/null  # or equivalent

Identify:

Existing scene count and names
Current totalChapters / composition duration
Where to insert / which scenes to modify

Target only scenes affected by user's request. Preserve all unchanged scenes.

Step 3.5 — Implement Scene Files

Scene file anatomy (follow exactly)

import { AbsoluteFill, useCurrentFrame, interpolate } from 'remotion';
import { C, ProgressBar, ChapterBadge } from '../components/Shared';  // adjust path
import { easeOut, staggeredEaseOut } from '../utils/animations';       // adjust path

// Data arrays at the top — keep out of component body
const ITEMS = [ ... ];

export const Scene{NN}{Name}: React.FC = () => {
    const frame = useCurrentFrame();

    return (
        <AbsoluteFill style={{ background: C.bg, fontFamily: 'system-ui, -apple-system, sans-serif' }}>
            <ChapterBadge index={NN} label="{Scene Name}" color={C.blue} />

            <div style={{ position: 'absolute', inset: 0, display: 'flex', gap: 48, padding: '68px 72px 44px' }}>
                {/* Content here */}
            </div>

            <ProgressBar chapterIndex={NN - 1} totalChapters={TOTAL} />
        </AbsoluteFill>
    );
};

Animation rules

Element	Pattern
Eyebrow label	`opacity: easeOut(frame, 0, 14)`
Hero title	`opacity: easeOut(frame, 8, 22)` + `translateY` from 28→0
Subtitle	`opacity: easeOut(frame, 22, 18)`
List items (stagger)	`staggeredEaseOut(frame, i, startAt, 12, 16)`
Cards (stagger up)	`staggeredEaseOut` + `translateY(20→0)`
Cards (stagger right)	`staggeredEaseOut` + `translateX(28→0)`
Late callout boxes	`easeOut(frame, 90+, 18)`

Layout patterns

Left/Right split (most common):

<div style={{ position: 'absolute', inset: 0, display: 'flex', gap: 48, padding: '68px 72px 44px' }}>
    <div style={{ width: 400, flexShrink: 0, ... }}>  {/* Left panel */}
    <div style={{ flex: 1, ... }}>                     {/* Right panel */}
</div>

Full-width column:

<div style={{ position: 'absolute', inset: 0, display: 'flex', flexDirection: 'column', padding: '68px 64px 44px', gap: 16 }}>

Centered (title/CTA scene):

<div style={{ position: 'absolute', inset: 0, display: 'flex', flexDirection: 'column', justifyContent: 'center', alignItems: 'center', padding: '72px 100px', textAlign: 'center' }}>

Card grid:

<div style={{ display: 'grid', gridTemplateColumns: 'repeat(4, 1fr)', gap: 12 }}>

Color and font guidelines

Element	fontSize	fontWeight	Notes
Eyebrow label	14	700	category color, `letterSpacing: 3`
Hero title	44–56	800	`C.text`, `lineHeight: 1.1`
Body text	17–21	400	`C.dim`, `lineHeight: 1.6`
Card label	15–16	700	category color
Monospace detail	12–14	400	`fontFamily: 'Courier New'`
Card container	—	—	`C.surface`, `borderLeft: 3px solid color`, `borderRadius: 10–12`

Step 3.6 — Wire Root.tsx

Multi-scene composition (with transitions)

import { TransitionSeries, linearTiming } from '@remotion/transitions';
import { fade } from '@remotion/transitions/fade';
import { Scene01Intro } from './compositions/Scene01Intro';
// ... other imports

const T = 18; // transition duration in frames

const D = {
    s01: 210, // 7s
    s02: 240 // 8s
    // ...
};

const SCENES = Object.values(D).length;
export const TOTAL_DURATION_FRAMES = Object.values(D).reduce((a, b) => a + b, 0) - (SCENES - 1) * T;

const tr = () => <TransitionSeries.Transition presentation={fade()} timing={linearTiming({ durationInFrames: T })} />;

export const {
    CompositionName
}: React.FC = () => (
    <TransitionSeries>
        <TransitionSeries.Sequence durationInFrames={D.s01}>
            <Scene01Intro />
        </TransitionSeries.Sequence>
        {tr()}
        <TransitionSeries.Sequence durationInFrames={D.s02}>
            <Scene02Next />
        </TransitionSeries.Sequence>
        {/* ... */}
    </TransitionSeries>
);

// Root.tsx
import { Composition } from 'remotion';
import { {CompositionName}, TOTAL_DURATION_FRAMES } from './{CompositionName}';

export const Root: React.FC = () => (
    <Composition id="{CompositionId}" component={{{CompositionName}}} durationInFrames={TOTAL_DURATION_FRAMES} fps={30} width={1920} height={1080} />
);

Single-scene composition

// Root.tsx
import { Composition } from 'remotion';
import { MyScene } from './compositions/MyScene';

export const Root: React.FC = () => <Composition id="MyVideo" component={MyScene} durationInFrames={300} fps={30} width={1920} height={1080} />;

Step 3.7 — Post-scaffold: launch prompt

After creating/updating, report changed files and offer launch:

✅ Created {N} scene files in {PROJECT_PATH}/{source-root}/compositions/
   Total duration: ~{X}s ({FRAMES} frames @ 30fps)

To preview: run `/remotion play` — starts Remotion Studio at http://localhost:3000
To render:  cd {PROJECT_PATH} && npm run render

Update Mode: Specific Scenarios

Add a new scene

Read Root.tsx to find composition orchestrator and current scene count
Read totalChapters across existing scenes
Determine insertion point (end = safest)
Create new scene file following anatomy above
Update Root / composition orchestrator:
- Add import
- Add D.sNN entry
- Add <TransitionSeries.Sequence> block
- MUST ATTENTION update totalChapters in ALL existing scene files (+1)

Modify an existing scene

Read specific scene file
Identify data array or JSX block needing change
Make surgical edits only — do not touch unrelated sections

Change visual style / palette

Edit {source-root}/components/Shared.tsx → C object
Font changes: update fontFamily in AbsoluteFill style per scene (or add global in Shared)

Remotion API Reference

Before implementing beyond basic scene creation, read the relevant sections of references/remotion-skill-api-recipes.md:

Animation timing, sequencing, compositions, assets, images/video/audio, GIFs and fonts: read those sections before implementing these features.
Transitions, overlays, 3D, text effects/measurement and DOM measurement: read the matching section before implementation.
Captions, dynamic metadata, Zod parameters, Mediabunny, FFmpeg/silence detection and audio visualization: read the matching section before using these APIs.
Lottie, charts, maps, transparent rendering, voiceover, sound effects and Tailwind: read the matching section before implementation.

Keep animations frame-driven and use Remotion media components and staticFile() for public assets. Copy specialized implementations from the refs/ owners listed above.

Closing Reminders

Protocols in force (concise digest of the SYNC/shared blocks this skill carries):

MUST ATTENTION wait for user approval of scene plan (Step 3.3) — NEVER implement scenes before approval
MUST ATTENTION read existing project structure (Step 3.4) before modifications — NEVER overwrite blindly
MUST ATTENTION update totalChapters in ALL scene files when adding/removing scenes — one missed file causes visual regression
MUST ATTENTION keep data arrays outside component body — NEVER define const ITEMS inside component function
MUST ATTENTION use npx create-video@latest --yes --blank --no-tailwind for scaffold — NEVER npm init unless fallback needed
MUST ATTENTION use staggeredEaseOut for list/card reveals — NEVER all-at-once opacity
MUST ATTENTION verify PROJECT_EXISTS before Play mode — report missing project and exit
MUST ATTENTION use TaskCreate to plan ALL work before starting — mark each task done immediately
MUST ATTENTION ALL animations driven by useCurrentFrame() — CSS transitions, CSS animations, Tailwind animate/transition classes FORBIDDEN
MUST ATTENTION use Remotion components <Img>, <Video>, <Audio> — NEVER native HTML elements
MUST ATTENTION use staticFile() for all public/ folder assets — NEVER raw relative paths
MUST ATTENTION Copy from appropriate refs/ file — NEVER implement text animations, captions, mediabunny, maps, or voiceover from memory