Tracely-ai: Skill for Claude Code

GSAP Timeline

When to Use This Skill

Apply when building multi-step animations, coordinating several tweens in sequence or parallel, or when the user asks about timelines, sequencing, or keyframe-style animation in GSAP.

Related skills: For single tweens and eases use gsap-core; for scroll-driven timelines use gsap-scrolltrigger; for React use gsap-react.

Creating a Timeline

const tl = gsap.timeline();
tl.to(".a", { x: 100, duration: 1 })
  .to(".b", { y: 50, duration: 0.5 })
  .to(".c", { opacity: 0, duration: 0.3 });

By default, tweens are appended one after another. Use the position parameter to place tweens at specific times or relative to other tweens.

Position Parameter

Third argument (or position property in vars) controls placement:

• Absolute: 1 — start at 1 second.
• Relative (default): "+=0.5" — 0.5s after end; "-=0.2" — 0.2s before end.
• Label: "labelName" — at that label; "labelName+=0.3" — 0.3s after label.
• Placement: "<" — start when recently-added animation starts; ">" — start when recently-added animation ends (default); "<0.2" — 0.2s after recently-added animation start.

Examples:

tl.to(".a", { x: 100 }, 0);           // at 0
tl.to(".b", { y: 50 }, "+=0.5");      // 0.5s after last end
tl.to(".c", { opacity: 0 }, "<");     // same start as previous
tl.to(".d", { scale: 2 }, "<0.2");    // 0.2s after previous start

Timeline Defaults

Pass defaults into the timeline so all child tweens inherit:

const tl = gsap.timeline({ defaults: { duration: 0.5, ease: "power2.out" } });
tl.to(".a", { x: 100 }).to(".b", { y: 50 }); // both use 0.5s and power2.out

Timeline Options (constructor)

• paused: true — create paused; call .play() to start.
• repeat, yoyo — same as tweens; apply to whole timeline.
• onComplete, onStart, onUpdate — timeline-level callbacks.
• defaults — vars merged into every child tween.