Lottie Motion Builder

Use Lottie for small deployable motion assets, not for full cinematic motion-design work.

Good Fits

• SVG path reveal
• logo or wordmark animation
• loader, empty-state, success-state, and transition animation
• small branded motion element for web, mobile, or app onboarding

Do Not Use It For

• long character animation
• complex scene choreography
• vague "make it cool" requests with no asset grounding
• motion work that does not need to ship as Lottie JSON

Required Inputs

Before building, lock these down:

• source asset: SVG, screenshot, logo, icon, or concrete visual reference;
• target surface: landing page, app UI, loader, hero accent, onboarding, etc.;
• duration and loop behavior;
• target runtime: web, React Native, iOS, Android, or generic Lottie JSON;
• editable controls needed at runtime: background, color, size, stroke, speed, etc.

If the user gives only a vague motion request, ask for or derive one concrete asset first.

Harness Rule

Use the external diffusionstudio/lottie harness rather than inventing a custom player.

• Read references/external-harness.md before setup.
• Bootstrap or refresh the harness with scripts/bootstrap_harness.sh.
• Keep generated animation files inside the harness project while iterating.
• Treat the upstream harness as the rendering contract for preview and slot behavior.

Workflow

1. Confirm the asset, target surface, duration, loop mode, and runtime target.
2. Bootstrap the external harness if needed.
3. Generate or edit public/lottie.json in the harness project.
4. Expose at least one background-color control and any explicitly requested controls.
5. Run the local preview and visually verify the result.
6. Run motion-review-gate when the asset is meant for a product UI surface rather than a throwaway demo.
7. Export the usable artifact set and summarize how to embed it.

Output Contract

Produce these artifacts when the user asks for a usable result:

• animation.json or the final lottie.json;
• one visual verification artifact: screenshot, gif, or short mp4;
• a short embed note for the target runtime;
• any runtime-editable controls used by the animation.

Verification

• The JSON parses in the harness.
• The motion is visible and not blank.
• Loop points are intentional.
• Background control exists.
• Dimensions, duration, and FPS match the request.
• The asset is small enough for the intended product surface.
• Product-surface motion has passed motion-review-gate or the exception is stated.

Reporting

In the final report, include:

• source asset used;
• output path;
• preview path or URL;
• runtime target;
• controls exposed;
• known limitations.