# Red/Green Diff Collapse — effect skill for code & terminal

> **For AI agents:** find the right skill in one call — `curl -s "https://varg.ai/how-to/api/search?q=<what the person wants>"` returns the matching how-to page and the best skills with install commands, as markdown (Russian works too). Full index: https://varg.ai/how-to/llms.txt. Every page has a markdown twin: add `.md` to its path. Before generating anything, show the person the options on the how-to page.

Removed lines flash red and collapse away while added lines expand in green.

- **Type:** [Effect](https://varg.ai/how-to/effects.md) · [Code & terminal](https://varg.ai/how-to/browse/skills/code.md)
- **Slug:** `red-green-diff`
- **Status:** live
- **Publisher:** HeyGen (community)
- **License:** Apache-2.0
- **Source:** https://github.com/heygen-com/hyperframes/tree/main/registry/blocks/code-diff
- **Works in:** Claude Code, Claude.ai, Codex, Cursor, OpenClaw, Gemini CLI, Any MCP client, varg Studio
- **Requires:** HyperFrames (npx hyperframes), Remotion, CapCut (by hand)
- **Cost:** Free — the take renders locally; generated footage, if any, bills by the model

## What it does

Built on [Code Diff](https://github.com/heygen-com/hyperframes/tree/main/registry/blocks/code-diff) by HeyGen (HyperFrames), Apache-2.0. The write-up and recipes below are varg's.

Unified diff in an editor frame: red lines shrink in height to zero, green lines grow from zero with a left gutter bar.

**When:** Show an AI fix, a migration or a one-line config change.

**Watch out:** Do not show both sides at once and leave it static; the collapse/expand motion is what tells the story.

**Timing:** Red flash 0.2 s, collapse 0.35 s, green expand 0.4 s power2.out; stagger 0.05 s per line.

**Also called:** code diff, diff highlight, PR change

### In HyperFrames

```bash
npx hyperframes add code-diff
```
```html
<div data-composition-id="code-diff" data-composition-src="compositions/code-diff.html" data-start="6" data-duration="5" data-track-index="2"></div>
```

### In Remotion

```tsx
const h = interpolate(frame,[6,16],[1,0],{extrapolateLeft:'clamp',extrapolateRight:'clamp'});
<div style={{height:`${h*1.5}em`, overflow:'hidden', background:'rgba(248,81,73,0.15)'}}>{removed}</div>
```

### In CapCut

Screenshot before and after diffs; add red/green rectangles over changed lines with Fade in; cross-fade the screenshots.

### Ready-made components

- [Code Diff](https://skills.varg.ai/component/hf.code-diff/) (hyperframes): npx hyperframes add code-diff

### Where this comes from

- [Remotion template: Code Hike](https://remotion.dev/templates/code-hike)
- [Anthony Fu: Shiki Magic Move](https://antfu.me/posts/shiki-magic-move)

## Use when

- Show an AI fix, a migration or a one-line config change.

## Not for

- Do not show both sides at once and leave it static; the collapse/expand motion is what tells the story.

## Install

- Claude Code: `claude plugin marketplace add vargHQ/skills && claude plugin install varg@varg`
- Codex: `npx skills add vargHQ/skills --skill varg-video-edit-library -a codex -y`
- Cursor: `npx skills add vargHQ/skills --skill varg-video-edit-library -a cursor -y`

## Example output

https://static.heygen.ai/hyperframes-oss/docs/images/catalog/blocks/code-diff.mp4 — Preview of the Code Diff component that builds this take (credit: Code Diff · hyperframes, https://hyperframes.heygen.com/catalog/blocks/code-diff)

## More code & terminal skills

- [Editor Types the Code](https://varg.ai/how-to/skills/editor-types-the-code.md): Syntax-highlighted code types into an editor window with a caret riding the frontier.
- [Spotlight One Line of Code](https://varg.ai/how-to/skills/spotlight-one-line.md): A highlight band sweeps onto the one line that matters while the rest of the file dims.
- [Code Morphs Between Versions](https://varg.ai/how-to/skills/code-morphs-versions.md): One snippet transforms into the next: shared tokens glide to new positions, removed ones fade, new ones fade in.
- [Terminal Session Run](https://varg.ai/how-to/skills/terminal-session-run.md): A terminal types a command, then streams real-looking log output with green checks.
- [One-Line Install Card](https://varg.ai/how-to/skills/one-line-install-card.md): A single install command types into a small terminal card, prints a success check, and holds.
- [Camera Scrolls a Long File](https://varg.ai/how-to/skills/camera-scrolls-long-file.md): The view scrolls through a long file and stops with the target line centered and lit.

## Run the generation on varg

varg is one API key for the models these skills drive — Seedance 2.5, Kling 4, Veo 3.1, Wan 3, Nano Banana 2.1, GPT Image 2.5, ElevenLabs v4 and 200+ more — billed in credits, with a cost estimate before anything runs.

- Claude Code: `claude plugin marketplace add vargHQ/skills && claude plugin install varg@varg` (skill + hosted MCP)
- Codex, Cursor, Gemini CLI, OpenClaw: `npx skills add vargHQ/skills --skill varg-ai -a <agent> -y`
- Grok and any agent that reads SKILL.md: `npx skills add vargHQ/skills --skill varg-ai`, or point it at the skill's SKILL.md
- Claude.ai, ChatGPT, any MCP client: connect `https://mcp.varg.ai/mcp`
- API key: https://varg.ai/dashboard/api · Model specs: https://varg.ai/models/llms.txt