GSAP & ScrollTrigger Development

Overview

GSAP (GreenSock Animation Platform) is the industry-leading JavaScript animation library for creating high-performance, production-quality animations. ScrollTrigger is GSAP's powerful plugin for scroll-driven animations. Together, they enable everything from simple UI transitions to complex scroll-based storytelling experiences.

Core Concepts

The Basics: Tweens

A tween is a single animation from point A to point B.

// Animate TO a state (from current)
gsap.to(".box", {
  x: 200,
  rotation: 360,
  duration: 1,
  ease: "power2.inOut"
});

// Animate FROM a state (to current)
gsap.from(".box", {
  opacity: 0,
  y: -50,
  duration: 0.8
});

// Animate FROM-TO (define both start and end)
gsap.fromTo(".box",
  { opacity: 0, scale: 0.5 }, // FROM
  { opacity: 1, scale: 1, duration: 1 } // TO
);

Timelines: Sequencing Animations

Timelines orchestrate multiple tweens in sequence or overlap.

const tl = gsap.timeline();

// Sequential by default
tl.to(".box1", { x: 100, duration: 1 })
  .to(".box2", { y: 100, duration: 1 })
  .to(".box3", { rotation: 360, duration: 1 });

// With labels for organization
tl.addLabel("start")
  .to(".hero", { opacity: 1, duration: 1 })
  .addLabel("reveal")
  .to(".content", { y: 0, duration: 0.8 }, "reveal") // Start at "reveal" label
  .to(".cta", { scale: 1, duration: 0.5 }, "reveal+=0.5"); // 0.5s after "reveal"

Position Parameter (Timeline Timing)

Control when animations start within a timeline:

const tl = gsap.timeline();

// Default: One after another
tl.to(".box1", { x: 100 })
  .to(".box2", { x: 100 }); // Starts after box1 finishes

// Start at the same time
tl.to(".box1", { x: 100 })
  .to(".box2", { y: 100 }, 0); // Starts at 0 seconds

// Relative positioning
tl.to(".box1", { x: 100, duration: 2 })
  .to(".box2", { y: 100 }, "-=1"); // Starts 1 second before box1 ends
  .to(".box3", { rotation: 360 }, "+=0.5"); // Starts 0.5s after box2 finishes

// At a specific time
tl.to(".box1", { x: 100 }, 2.5); // Starts at 2.5 seconds

ScrollTrigger Fundamentals

Basic Scroll Animation

gsap.registerPlugin(ScrollTrigger);

gsap.to(".box", {
  x: 500,
  scrollTrigger: {
    trigger: ".box",
    start: "top center", // When top of trigger hits center of viewport
    end: "bottom center",
    markers: true, // Development only - shows start/end positions
    scrub: true, // Links animation to scrollbar
    toggleActions: "play none none reverse" // onEnter onLeave onEnterBack onLeaveBack
  }
});

Start & End Positions

Format: "[trigger position] [viewport position]"

// Common patterns
start: "top top"      // Trigger top hits viewport top
start: "top center"   // Trigger top hits viewport center (default)
start: "top bottom"   // Trigger top hits viewport bottom
start: "center center" // Trigger center hits viewport center

// With offsets
start: "top top+=100"   // 100px below viewport top
start: "top 80%"        // 80% down the viewport
end: "+=500"            // 500px after start position
end: "bottom top"       // Trigger bottom hits viewport top

Scrubbing (Scroll-Synced Animation)

// Boolean: Direct link to scrollbar (immediate)
scrub: true

// Number: Smoothing delay in seconds
scrub: 1  // Takes 1 second to "catch up" to scrollbar
scrub: 0.5 // Faster, tighter feel

Toggle Actions

Control animation at four scroll points:

toggleActions: "play pause resume reset"
// onEnter | onLeave | onEnterBack | onLeaveBack

// Actions: play, pause, resume, restart, reset, complete, reverse, none

Common patterns:

how to use gsap-scrolltrigger
CursorClaude CodeClineCodexWindsurfGooseGitHub CopilotVS CodeGemini CLIKiloOpencodeKimi CLIRoo ClineAiderContinueZedBolt.newLovablev0Replit AgentSweepSmol DeveloperDevinCavemanAmpAntigravity
How to use gsap-scrolltrigger on Cursor
AI-first code editor with Composer
1
Prerequisites
Before installing skills in Cursor, ensure your development environment meets these requirements:
›Cursor installed and configured on your development machine
›Node.js version 16.0+ with npm package manager (verify with node --version)
›Active project directory or workspace where you want to add gsap-scrolltrigger
2
Execute installation command
Execute the skills CLI command in your project's root directory to begin installation:
$npx skills add https://github.com/freshtechbro/claudedesignskills --skill gsap-scrolltriggercopy
The skills CLI fetches gsap-scrolltrigger from GitHub repository freshtechbro/claudedesignskills and configures it for Cursor.
3
Select Cursor when prompted
The CLI will show a list of available agents. Use arrow keys to navigate and space to select Cursor:
◆ Which agents do you want to install to?
│
│ ── Universal (.agents/skills) ── always included ────
│   • Amp
│   • Antigravity
│   • Cline
│   • Codex
│ ●Cursor(selected)
│   • Cursor
│   • Windsurf
4
Verify installation
Confirm successful installation by checking the skill directory location:
.cursor/skills/gsap-scrolltrigger
Reload or restart Cursor to activate gsap-scrolltrigger. Access the skill through slash commands (e.g., /gsap-scrolltrigger) or your agent's skill management interface.
⚠
Security & Verification Notice
We perform automated surface-level scans (Gen AI Scanner, Socket, Snyk) during installation. These checks detect common vulnerabilities but do not guarantee complete security. Always review skill source code and verify the publisher's reputation before production use.
Skills execute code in your development environment. Always verify the publisher's identity, review recent commits, and test in isolated environments before production deployment.
Additional Resources
›View source code on GitHub›Skills CLI documentation›Learn more about Cursor›What are agent skills?