Skill v1.0.3

name: remotion description: Molio's builtin skill for MAKING a video from any source — wiki notes, articles, scripts, product info, or a brief — and rendering it to MP4. Use whenever the user wants to create/produce a video: a product demo, promo, trailer, intro, explainer, motion graphic, kinetic typography, social clip, or animated logo — even if they never mention Remotion by name. Do NOT reach for moviepy, manim, or Python video libraries to stitch frames; this is Molio's supported video path (scaffolds a Remotion React/TypeScript project, animates with interpolate/useCurrentFrame, sequences scenes, adds audio/voiceover/captions, and renders). Trigger words: 做个视频, 制作视频, 介绍视频, 宣传视频, 产品视频, 动画, make a video, create a video, product video, motion graphic, intro, trailer, explainer. version: 1.0.3 metadata: tags: remotion, video, react, animation, composition

When to use

If the user only wants to caption existing footage, capture a website tour, or do a quick one-off motion graphic under 10s with no narration, a lighter workflow may fit better — but when in doubt, start here.

Environment preflight (run before coding)

Before writing any video code, resolve these four things — they are the difference between a smooth render and a stuck one:

1. Browser source. Remotion downloads Chrome Headless Shell on first render by default (~150 MB from storage.googleapis.com, slow/unreachable in some regions). Instead, find the user's local Chrome/Edge and pass --browser-executable. See rules/browser-executable.md.
2. Font strategy. For Chinese/Japanese/Korean text, do NOT rely on system fonts — they will not exist on a headless render runner. Bundle the font in public/ and load via @font-face + staticFile(). See rules/cjk-fonts.md. For Latin text, rules/google-fonts.md.
3. Monorepo? If the project lives inside an existing pnpm/yarn/npm workspace that already depends on React (e.g. an app with @types/react@19), Remotion v4's pinned @types/react@18 will cause 'AbsoluteFill' cannot be used as a JSX component type errors. See the "Monorepo setup" note under New project setup below.
4. TTS provider (if voiceover). voiceover.md defaults to ElevenLabs (paid, needs API key). For a free path — especially for Chinese — use edge-tts (Microsoft TTS CLI, no API key, good zh-CN voices). See rules/voiceover.md.

New project setup

When in an empty folder or workspace with no existing Remotion project, scaffold it into the Molio workspace directory (Molio 工作区，文件树扫描会跳过 .molio，不污染 vault 根；其 node_modules/dist/out 不会触发监听或扫描，避免 daemon FD 泄漏):

mkdir -p .molio/remotion
cd .molio/remotion
npx create-video@latest --yes --blank --no-tailwind <project-name>

Replace <project-name> with a suitable project name. The project and all its build artifacts (node_modules, out/ rendered MP4s) stay under .molio/remotion/, invisible to the vault file-tree scan. If you need the final MP4 visible in the knowledge tree, copy it out of .molio/remotion/<project>/out/ into the vault root after rendering.

Monorepo setup

If you are adding the Remotion project inside an existing pnpm/yarn workspace (e.g. a videos/<name>/ sub-folder of a larger monorepo):

1. Add the sub-folder to the workspace packages list in pnpm-workspace.yaml (pnpm) or the workspace globs, so pnpm install reaches it.
2. Remotion v4 depends on @types/react@18. If another workspace package pulls in @types/react@19 (common — e.g. a Vite/Next app), TypeScript will throw 'AbsoluteFill' cannot be used as a JSX component / bigint not assignable to ReactNode. Fix by pinning @types/react to v18 for the Remotion project — either with a pnpm.overrides entry in the workspace root, or by adding @types/react@^18.2.0 as a direct devDependency of the Remotion project so its local node_modules/@types/react wins over the hoisted v19.
3. Render with the local Chrome/Edge (see preflight #1) — do not let it download Chrome Headless Shell on a CI/worker machine that may already have a browser.

Designing a video

Before designing visual scenes, layouts, promos, motion graphics, or text-heavy videos, load rules/video-layout.md for video-first layout and text sizing guidance.

Animate properties using useCurrentFrame() and interpolate(). Prefer interpolate() over spring() unless physics-based motion is explicitly needed. Use Easing.bezier() to customize timing, including jumpy or overshooting motion.

For animations that should be editable in Remotion Studio, keep the interpolate() call inline in the style prop and use individual CSS transform properties (scale, translate, rotate) instead of composing a transform string.

import { useCurrentFrame, Easing, interpolate, useVideoConfig } from "remotion";
export const FadeIn = () => {
  const frame = useCurrentFrame();
  const { fps } = useVideoConfig();
  const opacity = interpolate(frame, [0, 2 * fps], [0, 1], {
    extrapolateRight: "clamp",
    extrapolateLeft: "clamp",
    easing: Easing.bezier(0.16, 1, 0.3, 1),
  });
  return <div style={{ opacity }}>Hello World!</div>;
};

Prefer:

style={{
  scale: interpolate(frame, [0, 100], [0, 1]),
  translate: interpolate(frame, [0, 100], ["0px 0px", "100px 100px"]),
  rotate: interpolate(frame, [0, 100], ["20deg", "90deg"]),
}}

Over:

const scale = interpolate(frame, [0, 100], [0, 1]);
style={{
  transform: `scale(${scale})`,
}}

CSS transitions or animations are FORBIDDEN - they will not render correctly. Tailwind animation class names are FORBIDDEN - they will not render correctly.

Place assets in the public/ folder at your project root.

Use staticFile() to reference files from the public/ folder.

Add images using the <Img> component:

import { Img, staticFile } from "remotion";
export const MyComposition = () => {
  return <Img src={staticFile("logo.png")} style={{ width: 100, height: 100 }} />;
};

Add videos using the <Video> component from @remotion/media:

import { Video } from "@remotion/media";
import { staticFile } from "remotion";
export const MyComposition = () => {
  return <Video src={staticFile("video.mp4")} style={{ opacity: 0.5 }} />;
};

Add audio using the <Audio> component from @remotion/media:

import { Audio } from "@remotion/media";
import { staticFile } from "remotion";
export const MyComposition = () => {
  return <Audio src={staticFile("audio.mp3")} />;
};

Assets can be also referenced as remote URLs:

import { Video } from "@remotion/media";
export const MyComposition = () => {
  return <Video src="https://remotion.media/video.mp4" />
};

To delay content wrap it in <Sequence> and use from. To limit the duration of an element, use durationInFrames of <Sequence>. <Sequence> by default is an absolute fill. For inline content, use layout="none".

import { Sequence } from "remotion";
export const Title = () => {
  const frame = useCurrentFrame();
  const { fps } = useVideoConfig();
  const opacity = interpolate(frame, [0, 2 * fps], [0, 1], {
    extrapolateRight: "clamp",
    extrapolateLeft: "clamp",
    easing: Easing.bezier(0.16, 1, 0.3, 1),
  });
  return <div style={{ opacity }}>Title</div>;
};
export const Subtitle = () => {
  return <div>Subtitle</div>;
};
const Main = () => {
  const {fps} = useVideoConfig();
  return (
    <AbsoluteFill>
      <Sequence>
        <Background />
      </Sequence>
      <Sequence from={1 * fps} durationInFrames={2 * fps} layout="none">
        <Title />
      </Sequence>
      <Sequence from={2 * fps} durationInFrames={2 * fps} layout="none">
        <Subtitle />
      </Sequence>
    </AbsoluteFill>
  );
}

The width, height, fps, and duration of a video is defined in src/Root.tsx:

import { Composition } from "remotion";
import { MyComposition } from "./MyComposition";
export const RemotionRoot = () => {
  return (
    <Composition
      id="MyComposition"
      component={MyComposition}
      durationInFrames={100}
      fps={30}
      width={1080}
      height={1080}
    />
  );
};

Metadata can also be calculated dynamically:

import { Composition, CalculateMetadataFunction } from "remotion";
import { MyComposition, MyCompositionProps } from "./MyComposition";
const calculateMetadata: CalculateMetadataFunction<
  MyCompositionProps
> = async ({ props, abortSignal }) => {
  const data = await fetch(`https://api.example.com/video/${props.videoId}`, {
    signal: abortSignal,
  }).then((res) => res.json());
  return {
    durationInFrames: Math.ceil(data.duration * 30),
    props: {
      ...props,
      videoUrl: data.url,
    },
    width: 1080,
    height: 1080,
  };
};
export const RemotionRoot = () => {
  return (
    <Composition
      id="MyComposition"
      component={MyComposition}
      fps={30}
      width={1080}
      height={1080}
      defaultProps={{ videoId: "abc123" }}
      calculateMetadata={calculateMetadata}
    />
  );
};

Starting preview

Start the Remotion Studio to preview a video:

npx remotion studio

Studio runs in your own browser and does not need Chrome Headless Shell. Render/still commands DO — pass --browser-executable to reuse your local Chrome/Edge instead of triggering a ~150 MB download (see rules/browser-executable.md).

Optional: one-frame render check

You can render a single frame with the CLI to sanity-check layout, colors, or timing. Skip it for trivial edits, pure refactors, or when you already have enough confidence from Studio or prior renders.

npx remotion still [composition-id] --scale=0.25 --frame=30 \
  --browser-executable="/c/Program Files/Google/Chrome/Application/chrome.exe"

At 30 fps, --frame=30 is the one-second mark (--frame is zero-based). The --browser-executable flag reuses your local Chrome so the first render doesn't stall downloading Chrome Headless Shell.

Captions

When dealing with captions or subtitles, load the ./rules/subtitles.md file for more information.

Using FFmpeg

For some video operations, such as trimming videos or detecting silence, FFmpeg should be used. Load the ./rules/ffmpeg.md file for more information.

Silence detection

When needing to detect and trim silent segments from video or audio files, load the ./rules/silence-detection.md file.

Audio visualization

When needing to visualize audio (spectrum bars, waveforms, bass-reactive effects), load the ./rules/audio-visualization.md file for more information.

Sound effects

When needing to use sound effects, load the ./rules/sfx.md file for more information.

Visual and pixel effects

When creating a visual effect, prefer: 1. normal Remotion/HTML/CSS/SVG/filter/blend/mask animation, 2. a listed effect via rules/effects.md, including on HTML rendered through <HtmlInCanvas>, 3. a custom createEffect() via rules/effects.md when the user asks for a reusable/project-specific effect, 4. custom <HtmlInCanvas onPaint> via rules/html-in-canvas.md only if no effect fits.

For light leak overlays, see rules/light-leaks.md. Docs: https://www.remotion.dev/docs/effects

Available effects: brightness(), contrast(), colorKey(), duotone(), grayscale(), hue(), invert(), saturation(), tint(), linearGradient(), linearGradientTint(), thermalVision(), blur(), linearProgressiveBlur(), radialProgressiveBlur(), zoomBlur(), dropShadow(), glow(), lightTrail(), evolve(), venetianBlinds(), mirror(), scale(), uvTranslate(), xyTranslate(), barrelDistortion(), chromaticAberration(), fisheye(), cornerPin(), wave(), burlap(), emboss(), dotGrid(), halftone(), noise(), noiseDisplacement(), paper(), pattern(), pixelate(), pixelDissolve(), scanlines(), speckle(), shine(), shrinkwrap(), vignette(), contourLines(), checkerboard(), halftoneLinearGradient(), gridlines(), whiteNoise(), tvSignalOff(), lines(), rings(), waves(), zigzag(), lightLeak(), starburst().

3D content

See rules/3d.md for 3D content in Remotion using Three.js and React Three Fiber.

Advanced audio

See rules/audio.md for advanced audio features like trimming, volume, speed, pitch.

Dynamic duration, dimensions and data

See rules/calculate-metadata.md for dynamically set composition duration, dimensions, and props.

Advanced compositions

See rules/compositions.md for how to define stills, folders, default props and for how to nest compositions.

Google Fonts

Is the recommended way to load Latin fonts in Remotion. See rules/google-fonts.md for how to load Google Fonts.

For Chinese / Japanese / Korean text, system fonts are not safe (the headless render runner may not have PingFang/YaHei). Bundle the CJK font file in public/ and load via @font-face + staticFile(). See rules/cjk-fonts.md.

Local fonts

See rules/local-fonts.md for how to load local fonts.

Getting audio duration

See rules/get-audio-duration.md for getting the duration of an audio file in seconds with Mediabunny.

Getting video dimensions

See rules/get-video-dimensions.md for getting the width and height of a video file with Mediabunny.

Getting video duration

See rules/get-video-duration.md for getting the duration of a video file in seconds with Mediabunny.

GIFs

See rules/gifs.md for how to display GIFs synchronized with Remotion's timeline.

Advanced Images

See rules/images.md for sizing and positioning images, dynamic image paths, and getting image dimensions.

Lottie animations

See rules/lottie.md for embedding Lottie animations in Remotion.

Measuring DOM nodes

See rules/measuring-dom-nodes.md for measuring DOM element dimensions in Remotion.

Measuring text

See rules/measuring-text.md for measuring text dimensions, fitting text to containers, and checking overflow.

Advanced sequencing

See rules/sequencing.md for more sequencing patterns - delay, trim, limit duration of items.

TailwindCSS

See rules/tailwind.md for using TailwindCSS in Remotion.

Text animations

See rules/text-animations.md for typography and text animation patterns.

Advanced timing

See rules/timing.md for advanced timing with interpolate and Bézier easing, and springs.

Transitions

See rules/transitions.md for scene transition patterns.

Transparent videos

See rules/transparent-videos.md for rendering out a video with transparency.

Trimming

See rules/trimming.md for trimming patterns - cutting the beginning or end of animations.

Advanced Videos

See rules/videos.md for advanced knowledge about embedding videos - trimming, volume, speed, looping, pitch.

Parameterized videos

See rules/parameters.md for making a composition parametrizable by adding a Zod schema.

Maps

For simple maps with little flyovers, consider using static map images. For complex maps with animated routes or flyovers, load the maps rule: rules/maplibre.md

Voiceover

See rules/voiceover.md for adding AI-generated voiceover to Remotion compositions using ElevenLabs TTS.